| Safe Haskell | Safe-Inferred |
|---|---|
| Language | Haskell2010 |
Nix.Prelude
Description
This is a Prelude, but, please, do not put things in here,
put them into Nix.Utils. This module is a pass-through-multiplexer,
between our custom code (Nix.Utils) that shadows over the outside prelude that is in use (Relude)
Prelude module has a problem of being imported & used by other projects.
Nix.Utils as a module with a regular name does not have that problem.
Synopsis
- module Nix.Utils
- (++) :: [a] -> [a] -> [a]
- seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b
- filter :: (a -> Bool) -> [a] -> [a]
- zip :: [a] -> [b] -> [(a, b)]
- fst :: (a, b) -> a
- snd :: (a, b) -> b
- otherwise :: Bool
- map :: (a -> b) -> [a] -> [b]
- ($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- coerce :: forall {k :: RuntimeRep} (a :: TYPE k) (b :: TYPE k). Coercible a b => a -> b
- fromIntegral :: (Integral a, Num b) => a -> b
- realToFrac :: (Real a, Fractional b) => a -> b
- guard :: Alternative f => Bool -> f ()
- class IsList l where
- join :: Monad m => m (m a) -> m a
- class Bounded a where
- class Enum a where
- succ :: a -> a
- pred :: a -> a
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
- class Eq a where
- class Fractional a => Floating a where
- class Num a => Fractional a where
- (/) :: a -> a -> a
- recip :: a -> a
- fromRational :: Rational -> a
- class (Real a, Enum a) => Integral a where
- class Applicative m => Monad (m :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- class Num a where
- class Eq a => Ord a where
- class Read a
- class (Num a, Ord a) => Real a where
- toRational :: a -> Rational
- class (RealFrac a, Floating a) => RealFloat a where
- floatRadix :: a -> Integer
- floatDigits :: a -> Int
- floatRange :: a -> (Int, Int)
- decodeFloat :: a -> (Integer, Int)
- encodeFloat :: Integer -> Int -> a
- isNaN :: a -> Bool
- isInfinite :: a -> Bool
- isDenormalized :: a -> Bool
- isNegativeZero :: a -> Bool
- isIEEE :: a -> Bool
- atan2 :: a -> a -> a
- class (Real a, Fractional a) => RealFrac a where
- class Show a
- class Typeable (a :: k)
- class Monad m => MonadFail (m :: Type -> Type) where
- class IsString a where
- fromString :: String -> a
- class Functor f => Applicative (f :: Type -> Type) where
- class Foldable (t :: TYPE LiftedRep -> Type) where
- class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse :: Applicative f => (a -> f b) -> t a -> f (t b)
- sequenceA :: Applicative f => t (f a) -> f (t a)
- mapM :: Monad m => (a -> m b) -> t a -> m (t b)
- sequence :: Monad m => t (m a) -> m (t a)
- class Generic a
- class KnownNat (n :: Nat)
- class Semigroup a where
- class Semigroup a => Monoid a where
- data Bool
- type String = [Char]
- data Char
- data Double = D# Double#
- data Float = F# Float#
- data Int
- data Int8
- data Int16
- data Int32
- data Int64
- data Integer
- data Natural
- data Maybe a
- data Ordering
- data Ratio a
- type Rational = Ratio Integer
- data IO a
- data Word
- data Word8
- data Word16
- data Word32
- data Word64
- data Either a b
- data NonEmpty a = a :| [a]
- type Type = TYPE LiftedRep
- data Constraint
- class a ~R# b => Coercible (a :: k) (b :: k)
- data CallStack
- type family CmpNat (a :: Natural) (b :: Natural) :: Ordering where ...
- class Eq a => Hashable a where
- hashWithSalt :: Int -> a -> Int
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- const :: a -> b -> a
- (.) :: (b -> c) -> (a -> b) -> a -> c
- id :: a -> a
- data ByteString
- data Text
- data Map k a
- data HashMap k v
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- not :: Bool -> Bool
- rights :: [Either a b] -> [b]
- lefts :: [Either a b] -> [a]
- sort :: Ord a => [a] -> [a]
- partitionEithers :: [Either a b] -> ([a], [b])
- swap :: (a, b) -> (b, a)
- class Applicative f => Alternative (f :: Type -> Type) where
- class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where
- isRight :: Either a b -> Bool
- flip :: (a -> b -> c) -> b -> a -> c
- transpose :: [[a]] -> [[a]]
- concat :: Foldable t => t [a] -> [a]
- odd :: Integral a => a -> Bool
- even :: Integral a => a -> Bool
- reverse :: [a] -> [a]
- all :: Foldable t => (a -> Bool) -> t a -> Bool
- uncurry :: (a -> b -> c) -> (a, b) -> c
- stdin :: Handle
- stdout :: Handle
- (<**>) :: Applicative f => f a -> f (a -> b) -> f b
- data Handle
- class Bifunctor (p :: Type -> Type -> Type) where
- forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- newtype Predicate a = Predicate {
- getPredicate :: a -> Bool
- newtype Op a b = Op {
- getOp :: b -> a
- newtype Equivalence a = Equivalence {
- getEquivalence :: a -> a -> Bool
- class Contravariant (f :: Type -> Type) where
- newtype Comparison a = Comparison {
- getComparison :: a -> a -> Ordering
- phantom :: (Functor f, Contravariant f) => f a -> f b
- defaultEquivalence :: Eq a => Equivalence a
- defaultComparison :: Ord a => Comparison a
- comparisonEquivalence :: Comparison a -> Equivalence a
- (>$<) :: Contravariant f => (a -> b) -> f b -> f a
- (>$$<) :: Contravariant f => f b -> (a -> b) -> f a
- ($<) :: Contravariant f => f b -> b -> f a
- newtype Compose (f :: k -> Type) (g :: k1 -> k) (a :: k1) = Compose {
- getCompose :: f (g a)
- data Void
- vacuous :: Functor f => f Void -> f a
- absurd :: Void -> a
- data WrappedMonoid m
- mtimesDefault :: (Integral b, Monoid a) => b -> a -> a
- cycle1 :: Semigroup m => m -> m
- sortWith :: Ord b => (a -> b) -> [a] -> [a]
- class (Bifunctor t, Bifoldable t) => Bitraversable (t :: Type -> Type -> Type) where
- bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d)
- bisequence :: (Bitraversable t, Applicative f) => t (f a) (f b) -> f (t a b)
- bimapDefault :: Bitraversable t => (a -> b) -> (c -> d) -> t a c -> t b d
- bifor :: (Bitraversable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f (t c d)
- bifoldMapDefault :: (Bitraversable t, Monoid m) => (a -> m) -> (b -> m) -> t a b -> m
- class Bifoldable (p :: TYPE LiftedRep -> TYPE LiftedRep -> Type) where
- bitraverse_ :: (Bifoldable t, Applicative f) => (a -> f c) -> (b -> f d) -> t a b -> f ()
- bisequence_ :: (Bifoldable t, Applicative f) => t (f a) (f b) -> f ()
- bior :: Bifoldable t => t Bool Bool -> Bool
- binull :: Bifoldable t => t a b -> Bool
- bilength :: Bifoldable t => t a b -> Int
- bifor_ :: (Bifoldable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f ()
- bifoldrM :: (Bifoldable t, Monad m) => (a -> c -> m c) -> (b -> c -> m c) -> c -> t a b -> m c
- bifoldr' :: Bifoldable t => (a -> c -> c) -> (b -> c -> c) -> c -> t a b -> c
- bifoldlM :: (Bifoldable t, Monad m) => (a -> b -> m a) -> (a -> c -> m a) -> a -> t b c -> m a
- bifoldl' :: Bifoldable t => (a -> b -> a) -> (a -> c -> a) -> a -> t b c -> a
- bifind :: Bifoldable t => (a -> Bool) -> t a a -> Maybe a
- bielem :: (Bifoldable t, Eq a) => a -> t a a -> Bool
- biasum :: (Bifoldable t, Alternative f) => t (f a) (f a) -> f a
- biany :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool
- biand :: Bifoldable t => t Bool Bool -> Bool
- biall :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool
- biList :: Bifoldable t => t a a -> [a]
- nonEmpty :: [a] -> Maybe (NonEmpty a)
- showStackTrace :: IO (Maybe String)
- getStackTrace :: IO (Maybe [Location])
- class Monad m => MonadIO (m :: Type -> Type) where
- class IsLabel (x :: Symbol) a where
- fromLabel :: a
- zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()
- zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]
- unless :: Applicative f => Bool -> f () -> f ()
- replicateM_ :: Applicative m => Int -> m a -> m ()
- replicateM :: Applicative m => Int -> m a -> m [a]
- mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a
- mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])
- forever :: Applicative f => f a -> f b
- filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
- (<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
- (<$!>) :: Monad m => (a -> b) -> m a -> m b
- mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)
- mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)
- forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)
- newtype ZipList a = ZipList {
- getZipList :: [a]
- optional :: Alternative f => f a -> f (Maybe a)
- (&&&) :: Arrow a => a b c -> a b c' -> a b (c, c')
- newtype Identity a = Identity {
- runIdentity :: a
- withFile :: FilePath -> IOMode -> (Handle -> IO r) -> IO r
- stderr :: Handle
- withFrozenCallStack :: HasCallStack => (HasCallStack => a) -> a
- callStack :: HasCallStack => CallStack
- data TVar a
- data STM a
- writeTVar :: TVar a -> a -> STM ()
- throwSTM :: Exception e => e -> STM a
- readTVar :: TVar a -> STM a
- newTVar :: a -> STM (TVar a)
- catchSTM :: Exception e => STM a -> (e -> STM a) -> STM a
- data BufferMode
- data IORef a
- type FilePath = String
- prettySrcLoc :: SrcLoc -> String
- prettyCallStack :: CallStack -> String
- class (Typeable e, Show e) => Exception e where
- toException :: e -> SomeException
- fromException :: SomeException -> Maybe e
- displayException :: e -> String
- newtype Const a (b :: k) = Const {
- getConst :: a
- traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f ()
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f ()
- or :: Foldable t => t Bool -> Bool
- for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f ()
- foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
- find :: Foldable t => (a -> Bool) -> t a -> Maybe a
- concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
- asum :: (Foldable t, Alternative f) => t (f a) -> f a
- any :: Foldable t => (a -> Bool) -> t a -> Bool
- and :: Foldable t => t Bool -> Bool
- unfoldr :: (b -> Maybe (a, b)) -> b -> [a]
- tails :: [a] -> [[a]]
- subsequences :: [a] -> [[a]]
- sortOn :: Ord b => (a -> b) -> [a] -> [a]
- sortBy :: (a -> a -> Ordering) -> [a] -> [a]
- permutations :: [a] -> [[a]]
- isPrefixOf :: Eq a => [a] -> [a] -> Bool
- intersperse :: a -> [a] -> [a]
- intercalate :: [a] -> [[a]] -> [a]
- inits :: [a] -> [[a]]
- group :: Eq a => [a] -> [[a]]
- genericTake :: Integral i => i -> [a] -> [a]
- genericSplitAt :: Integral i => i -> [a] -> ([a], [a])
- genericReplicate :: Integral i => i -> a -> [a]
- genericLength :: Num i => [a] -> i
- genericDrop :: Integral i => i -> [a] -> [a]
- newtype Last a = Last {}
- newtype First a = First {}
- newtype Ap (f :: k -> Type) (a :: k) = Ap {
- getAp :: f a
- newtype Sum a = Sum {
- getSum :: a
- newtype Product a = Product {
- getProduct :: a
- newtype Endo a = Endo {
- appEndo :: a -> a
- newtype Dual a = Dual {
- getDual :: a
- newtype Any = Any {}
- newtype Alt (f :: k -> Type) (a :: k) = Alt {
- getAlt :: f a
- newtype All = All {}
- stimesMonoid :: (Integral b, Monoid a) => b -> a -> a
- stimesIdempotent :: Integral b => b -> a -> a
- data SomeNat = KnownNat n => SomeNat (Proxy n)
- type Nat = Natural
- someNatVal :: Natural -> SomeNat
- natVal :: forall (n :: Nat) proxy. KnownNat n => proxy n -> Natural
- newtype Down a = Down {
- getDown :: a
- comparing :: Ord a => (b -> a) -> b -> b -> Ordering
- reads :: Read a => ReadS a
- readMaybe :: Read a => String -> Maybe a
- isLeft :: Either a b -> Bool
- fromRight :: b -> Either a b -> b
- fromLeft :: a -> Either a b -> a
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- data Proxy (t :: k) = Proxy
- (>>>) :: forall {k} cat (a :: k) (b :: k) (c :: k). Category cat => cat a b -> cat b c -> cat a c
- (<<<) :: forall {k} cat (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c
- data IOMode
- byteSwap64 :: Word64 -> Word64
- byteSwap32 :: Word32 -> Word32
- byteSwap16 :: Word16 -> Word16
- xor :: Bits a => a -> a -> a
- toIntegralSized :: (Integral a, Integral b, Bits a, Bits b) => a -> Maybe b
- numerator :: Ratio a -> a
- lcm :: Integral a => a -> a -> a
- gcd :: Integral a => a -> a -> a
- denominator :: Ratio a -> a
- (^^) :: (Fractional a, Integral b) => a -> b -> a
- (^) :: (Num a, Integral b) => a -> b -> a
- boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a]
- boundedEnumFrom :: (Enum a, Bounded a) => a -> [a]
- chr :: Int -> Char
- zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
- zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
- unzip3 :: [(a, b, c)] -> ([a], [b], [c])
- unzip :: [(a, b)] -> ([a], [b])
- uncons :: [a] -> Maybe (a, [a])
- takeWhile :: (a -> Bool) -> [a] -> [a]
- take :: Int -> [a] -> [a]
- splitAt :: Int -> [a] -> ([a], [a])
- span :: (a -> Bool) -> [a] -> ([a], [a])
- scanr1 :: (a -> a -> a) -> [a] -> [a]
- scanr :: (a -> b -> b) -> b -> [a] -> [b]
- scanl1 :: (a -> a -> a) -> [a] -> [a]
- scanl' :: (b -> a -> b) -> b -> [a] -> [b]
- scanl :: (b -> a -> b) -> b -> [a] -> [b]
- replicate :: Int -> a -> [a]
- repeat :: a -> [a]
- iterate :: (a -> a) -> a -> [a]
- dropWhile :: (a -> Bool) -> [a] -> [a]
- drop :: Int -> [a] -> [a]
- break :: (a -> Bool) -> [a] -> ([a], [a])
- maybeToList :: Maybe a -> [a]
- maybe :: b -> (a -> b) -> Maybe a -> b
- mapMaybe :: (a -> Maybe b) -> [a] -> [b]
- listToMaybe :: [a] -> Maybe a
- isNothing :: Maybe a -> Bool
- isJust :: Maybe a -> Bool
- fromMaybe :: a -> Maybe a -> a
- catMaybes :: [Maybe a] -> [a]
- bool :: a -> a -> Bool -> a
- on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
- fix :: (a -> a) -> a
- (&) :: a -> (a -> b) -> b
- void :: Functor f => f a -> f ()
- (<&>) :: Functor f => f a -> (a -> b) -> f b
- ($>) :: Functor f => f a -> b -> f b
- curry :: ((a, b) -> c) -> a -> b -> c
- data MVar a
- subtract :: Num a => a -> a -> a
- currentCallStack :: IO [String]
- when :: Applicative f => Bool -> f () -> f ()
- ord :: Char -> Int
- minInt :: Int
- maxInt :: Int
- liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d
- asTypeOf :: a -> a -> a
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- ($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- type HasCallStack = ?callStack :: CallStack
- getCallStack :: CallStack -> [([Char], SrcLoc)]
- stimesIdempotentMonoid :: (Integral b, Monoid a) => b -> a -> a
- data SomeException = Exception e => SomeException e
- (&&) :: Bool -> Bool -> Bool
- (||) :: Bool -> Bool -> Bool
- fromShort :: ShortByteString -> ByteString
- data ShortByteString
- toShort :: ByteString -> ShortByteString
- data IdentityT (f :: k -> Type) (a :: k)
- data IntMap a
- data IntSet
- data Seq a
- data Set a
- class NFData a where
- rnf :: a -> ()
- deepseq :: NFData a => a -> b -> b
- ($!!) :: NFData a => (a -> b) -> a -> b
- newtype MaybeT (m :: Type -> Type) a = MaybeT {}
- newtype ExceptT e (m :: Type -> Type) a = ExceptT (m (Either e a))
- class Monad m => MonadState s (m :: Type -> Type) | m -> s where
- newtype StateT s (m :: Type -> Type) a = StateT {
- runStateT :: s -> m (a, s)
- class MonadTrans (t :: (Type -> Type) -> Type -> Type) where
- newtype ReaderT r (m :: Type -> Type) a = ReaderT {
- runReaderT :: r -> m a
- modify' :: MonadState s m => (s -> s) -> m ()
- modify :: MonadState s m => (s -> s) -> m ()
- gets :: MonadState s m => (s -> a) -> m a
- class Monad m => MonadReader r (m :: Type -> Type) | m -> r where
- asks :: MonadReader r m => (r -> a) -> m a
- runExceptT :: ExceptT e m a -> m (Either e a)
- runReader :: Reader r a -> r -> a
- withReader :: (r' -> r) -> Reader r a -> Reader r' a
- withReaderT :: forall r' r (m :: Type -> Type) a. (r' -> r) -> ReaderT r m a -> ReaderT r' m a
- type Reader r = ReaderT r Identity
- evalState :: State s a -> s -> a
- evalStateT :: Monad m => StateT s m a -> s -> m a
- execState :: State s a -> s -> s
- execStateT :: Monad m => StateT s m a -> s -> m s
- runState :: State s a -> s -> (a, s)
- withState :: (s -> s) -> State s a -> State s a
- type State s = StateT s Identity
- lookupEnv :: MonadIO m => String -> m (Maybe String)
- getArgs :: MonadIO m => m [String]
- putStrLn :: MonadIO m => String -> m ()
- putStr :: MonadIO m => String -> m ()
- print :: forall a m. (MonadIO m, Show a) => a -> m ()
- getLine :: MonadIO m => m Text
- anyM :: (Foldable f, Monad m) => (a -> m Bool) -> f a -> m Bool
- allM :: (Foldable f, Monad m) => (a -> m Bool) -> f a -> m Bool
- orM :: (Foldable f, Monad m) => f (m Bool) -> m Bool
- andM :: (Foldable f, Monad m) => f (m Bool) -> m Bool
- notElem :: (Foldable f, DisallowElem f, Eq a) => a -> f a -> Bool
- elem :: (Foldable f, DisallowElem f, Eq a) => a -> f a -> Bool
- product :: forall a f. (Foldable f, Num a) => f a -> a
- sum :: forall a f. (Foldable f, Num a) => f a -> a
- foldMapM :: (Monoid b, Monad m, Foldable f) => (a -> m b) -> f a -> m b
- foldMapA :: (Semigroup b, Monoid b, Applicative m, Foldable f) => (a -> m b) -> f a -> m b
- asumMap :: forall b m f a. (Foldable f, Alternative m) => (a -> m b) -> f a -> m b
- flipfoldl' :: Foldable f => (a -> b -> b) -> b -> f a -> b
- newEmptyTMVarIO :: MonadIO m => m (TMVar a)
- newTMVarIO :: MonadIO m => a -> m (TMVar a)
- readTVarIO :: MonadIO m => TVar a -> m a
- newTVarIO :: MonadIO m => a -> m (TVar a)
- atomically :: MonadIO m => STM a -> m a
- tryTakeMVar :: MonadIO m => MVar a -> m (Maybe a)
- tryReadMVar :: MonadIO m => MVar a -> m (Maybe a)
- tryPutMVar :: MonadIO m => MVar a -> a -> m Bool
- takeMVar :: MonadIO m => MVar a -> m a
- swapMVar :: MonadIO m => MVar a -> a -> m a
- readMVar :: MonadIO m => MVar a -> m a
- putMVar :: MonadIO m => MVar a -> a -> m ()
- newMVar :: MonadIO m => a -> m (MVar a)
- newEmptyMVar :: MonadIO m => m (MVar a)
- hGetBuffering :: MonadIO m => Handle -> m BufferMode
- hSetBuffering :: MonadIO m => Handle -> BufferMode -> m ()
- hIsEOF :: MonadIO m => Handle -> m Bool
- hFlush :: MonadIO m => Handle -> m ()
- partitionWith :: (a -> Either b c) -> [a] -> ([b], [c])
- maybeAt :: Int -> [a] -> Maybe a
- (!!?) :: [a] -> Int -> Maybe a
- type family OneItem x
- class One x where
- integerToNatural :: Integer -> Maybe Natural
- integerToBounded :: (Integral a, Bounded a) => Integer -> Maybe a
- (||^) :: Monad m => m Bool -> m Bool -> m Bool
- (&&^) :: Monad m => m Bool -> m Bool -> m Bool
- guarded :: Alternative f => (a -> Bool) -> a -> f a
- guardM :: MonadPlus m => m Bool -> m ()
- ifM :: Monad m => m Bool -> m a -> m a -> m a
- unlessM :: Monad m => m Bool -> m () -> m ()
- whenM :: Monad m => m Bool -> m () -> m ()
- evaluateNF_ :: (NFData a, MonadIO m) => a -> m ()
- evaluateNF :: (NFData a, MonadIO m) => a -> m a
- evaluateWHNF_ :: MonadIO m => a -> m ()
- evaluateWHNF :: MonadIO m => a -> m a
- bug :: (HasCallStack, Exception e) => e -> a
- pattern Exc :: Exception e => e -> SomeException
- data Bug = Bug SomeException CallStack
- tail :: IsNonEmpty f a [a] "tail" => f a -> [a]
- last :: IsNonEmpty f a a "last" => f a -> a
- init :: IsNonEmpty f a [a] "init" => f a -> [a]
- head :: IsNonEmpty f a a "head" => f a -> a
- whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m ()
- whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f ()
- viaNonEmpty :: (NonEmpty a -> b) -> [a] -> Maybe b
- infinitely :: Applicative f => f a -> f Void
- chainedTo :: Monad m => (a -> m b) -> m a -> m b
- whenRightM_ :: Monad m => m (Either l r) -> (r -> m ()) -> m ()
- whenRightM :: Monad m => a -> m (Either l r) -> (r -> m a) -> m a
- whenRight_ :: Applicative f => Either l r -> (r -> f ()) -> f ()
- whenRight :: Applicative f => a -> Either l r -> (r -> f a) -> f a
- whenLeftM_ :: Monad m => m (Either l r) -> (l -> m ()) -> m ()
- whenLeftM :: Monad m => a -> m (Either l r) -> (l -> m a) -> m a
- whenLeft_ :: Applicative f => Either l r -> (l -> f ()) -> f ()
- whenLeft :: Applicative f => a -> Either l r -> (l -> f a) -> f a
- maybeToLeft :: r -> Maybe l -> Either l r
- maybeToRight :: l -> Maybe r -> Either l r
- rightToMaybe :: Either l r -> Maybe r
- leftToMaybe :: Either l r -> Maybe l
- undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a
- error :: forall (r :: RuntimeRep) (a :: TYPE r) t. (HasCallStack, IsText t) => t -> a
- traceId :: String -> String
- traceShowM :: (Show a, Applicative f) => a -> f ()
- traceShowWith :: Show b => (a -> b) -> a -> a
- traceShowId :: Show a => a -> a
- traceShow :: Show a => a -> b -> b
- data Undefined = Undefined
- appendFileLBS :: MonadIO m => FilePath -> LByteString -> m ()
- writeFileLBS :: MonadIO m => FilePath -> LByteString -> m ()
- readFileLBS :: MonadIO m => FilePath -> m LByteString
- appendFileBS :: MonadIO m => FilePath -> ByteString -> m ()
- writeFileBS :: MonadIO m => FilePath -> ByteString -> m ()
- readFileBS :: MonadIO m => FilePath -> m ByteString
- appendFileLText :: MonadIO m => FilePath -> LText -> m ()
- writeFileLText :: MonadIO m => FilePath -> LText -> m ()
- readFileLText :: MonadIO m => FilePath -> m LText
- appendFileText :: MonadIO m => FilePath -> Text -> m ()
- writeFileText :: MonadIO m => FilePath -> Text -> m ()
- readFileText :: MonadIO m => FilePath -> m Text
- appendFile :: MonadIO m => FilePath -> String -> m ()
- writeFile :: MonadIO m => FilePath -> String -> m ()
- readFile' :: MonadIO m => FilePath -> m String
- putLBSLn :: MonadIO m => LByteString -> m ()
- putLBS :: MonadIO m => LByteString -> m ()
- putBSLn :: MonadIO m => ByteString -> m ()
- putBS :: MonadIO m => ByteString -> m ()
- putLTextLn :: MonadIO m => LText -> m ()
- putLText :: MonadIO m => LText -> m ()
- putTextLn :: MonadIO m => Text -> m ()
- putText :: MonadIO m => Text -> m ()
- fromStrict :: LazyStrict l s => s -> l
- fromLazy :: LazyStrict l s => l -> s
- show :: forall b a. (Show a, IsString b) => a -> b
- readEither :: Read a => String -> Either Text a
- type LText = Text
- type LByteString = ByteString
- class ConvertUtf8 a b where
- encodeUtf8 :: a -> b
- decodeUtf8 :: b -> a
- decodeUtf8Strict :: b -> Either UnicodeException a
- class ToText a where
- class ToLText a where
- class ToString a where
- class LazyStrict l s | l -> s, s -> l where
- unwords :: IsText t "unwords" => [t] -> t
- words :: IsText t "words" => t -> [t]
- unlines :: IsText t "unlines" => [t] -> t
- lines :: IsText t "lines" => t -> [t]
- intNubOn :: (a -> Int) -> [a] -> [a]
- intNub :: [Int] -> [Int]
- unstableNub :: Hashable a => [a] -> [a]
- sortNub :: Ord a => [a] -> [a]
- hashNub :: Hashable a => [a] -> [a]
- ordNubOn :: Ord b => (a -> b) -> [a] -> [a]
- ordNub :: Ord a => [a] -> [a]
- memptyIfTrue :: Monoid m => Bool -> m -> m
- memptyIfFalse :: Monoid m => Bool -> m -> m
- maybeToMonoid :: Monoid m => Maybe m -> m
- hoistEither :: forall (m :: Type -> Type) e a. Applicative m => Either e a -> ExceptT e m a
- hoistMaybe :: forall (m :: Type -> Type) a. Applicative m => Maybe a -> MaybeT m a
- executingState :: s -> State s a -> s
- executingStateT :: Functor f => s -> StateT s f a -> f s
- evaluatingState :: s -> State s a -> a
- evaluatingStateT :: Functor f => s -> StateT s f a -> f a
- usingState :: s -> State s a -> (a, s)
- usingStateT :: s -> StateT s m a -> m (a, s)
- etaReaderT :: forall r (m :: Type -> Type) a. ReaderT r m a -> ReaderT r m a
- usingReader :: r -> Reader r a -> a
- usingReaderT :: r -> ReaderT r m a -> m a
- mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b]
- whenNothingM_ :: Monad m => m (Maybe a) -> m () -> m ()
- whenNothingM :: Monad m => m (Maybe a) -> m a -> m a
- whenNothing_ :: Applicative f => Maybe a -> f () -> f ()
- whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
- (?:) :: Maybe a -> a -> a
- cycle :: [a] -> [a]
- atomicWriteIORef :: MonadIO m => IORef a -> a -> m ()
- atomicModifyIORef'_ :: MonadIO m => IORef a -> (a -> a) -> m ()
- atomicModifyIORef_ :: MonadIO m => IORef a -> (a -> a) -> m ()
- atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
- atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b
- modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m ()
- modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m ()
- writeIORef :: MonadIO m => IORef a -> a -> m ()
- readIORef :: MonadIO m => IORef a -> m a
- newIORef :: MonadIO m => a -> m (IORef a)
- die :: MonadIO m => String -> m a
- exitSuccess :: MonadIO m => m a
- exitFailure :: MonadIO m => m a
- exitWith :: MonadIO m => ExitCode -> m a
- inverseMap :: (Bounded a, Enum a, Ord k) => (a -> k) -> k -> Maybe a
- universeNonEmpty :: (Bounded a, Enum a) => NonEmpty a
- universe :: (Bounded a, Enum a) => [a]
- (??) :: Functor f => f (a -> b) -> a -> f b
- flap :: Functor f => f (a -> b) -> a -> f b
- (<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b)
- identity :: a -> a
- appliedTo :: Applicative f => f a -> f (a -> b) -> f b
- data HashSet a
- exceptToMaybeT :: forall (m :: Type -> Type) e a. Functor m => ExceptT e m a -> MaybeT m a
- maybeToExceptT :: forall (m :: Type -> Type) e a. Functor m => e -> MaybeT m a -> ExceptT e m a
- lenientDecode :: OnDecodeError
- strictDecode :: OnDecodeError
- type OnDecodeError = OnError Word8 Char
- type OnError a b = String -> Maybe a -> Maybe b
- data UnicodeException
- decodeUtf8' :: ByteString -> Either UnicodeException Text
- decodeUtf8With :: OnDecodeError -> ByteString -> Text
- isEmptyTMVar :: TMVar a -> STM Bool
- mkWeakTMVar :: TMVar a -> IO () -> IO (Weak (TMVar a))
- newEmptyTMVar :: STM (TMVar a)
- newTMVar :: a -> STM (TMVar a)
- putTMVar :: TMVar a -> a -> STM ()
- readTMVar :: TMVar a -> STM a
- swapTMVar :: TMVar a -> a -> STM a
- takeTMVar :: TMVar a -> STM a
- tryPutTMVar :: TMVar a -> a -> STM Bool
- tryReadTMVar :: TMVar a -> STM (Maybe a)
- tryTakeTMVar :: TMVar a -> STM (Maybe a)
- data TMVar a
- modifyTVar' :: TVar a -> (a -> a) -> STM ()
Documentation
module Nix.Utils
(++) :: [a] -> [a] -> [a] infixr 5 #
Append two lists, i.e.,
[x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn] [x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
If the first list is not finite, the result is the first list.
seq :: forall {r :: RuntimeRep} a (b :: TYPE r). a -> b -> b infixr 0 #
The value of seq a b is bottom if a is bottom, and
otherwise equal to b. In other words, it evaluates the first
argument a to weak head normal form (WHNF). seq is usually
introduced to improve performance by avoiding unneeded laziness.
A note on evaluation order: the expression seq a b does
not guarantee that a will be evaluated before b.
The only guarantee given by seq is that the both a
and b will be evaluated before seq returns a value.
In particular, this means that b may be evaluated before
a. If you need to guarantee a specific order of evaluation,
you must use the function pseq from the "parallel" package.
filter :: (a -> Bool) -> [a] -> [a] #
\(\mathcal{O}(n)\). filter, applied to a predicate and a list, returns
the list of those elements that satisfy the predicate; i.e.,
filter p xs = [ x | x <- xs, p x]
>>>filter odd [1, 2, 3][1,3]
zip :: [a] -> [b] -> [(a, b)] #
\(\mathcal{O}(\min(m,n))\). zip takes two lists and returns a list of
corresponding pairs.
>>>zip [1, 2] ['a', 'b'][(1,'a'),(2,'b')]
If one input list is shorter than the other, excess elements of the longer list are discarded, even if one of the lists is infinite:
>>>zip [1] ['a', 'b'][(1,'a')]>>>zip [1, 2] ['a'][(1,'a')]>>>zip [] [1..][]>>>zip [1..] [][]
zip is right-lazy:
>>>zip [] undefined[]>>>zip undefined []*** Exception: Prelude.undefined ...
zip is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
map :: (a -> b) -> [a] -> [b] #
\(\mathcal{O}(n)\). map f xs is the list obtained by applying f to
each element of xs, i.e.,
map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] map f [x1, x2, ...] == [f x1, f x2, ...]
>>>map (+1) [1, 2, 3][2,3,4]
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #
Application operator. This operator is redundant, since ordinary
application (f x) means the same as (f . However, $ x)$ has
low, right-associative binding precedence, so it sometimes allows
parentheses to be omitted; for example:
f $ g $ h x = f (g (h x))
It is also useful in higher-order situations, such as map ($ 0) xszipWith ($) fs xs
Note that ( is levity-polymorphic in its result type, so that
$)foo where $ Truefoo :: Bool -> Int# is well-typed.
coerce :: forall {k :: RuntimeRep} (a :: TYPE k) (b :: TYPE k). Coercible a b => a -> b #
The function coerce allows you to safely convert between values of
types that have the same representation with no run-time overhead. In the
simplest case you can use it instead of a newtype constructor, to go from
the newtype's concrete type to the abstract type. But it also works in
more complicated settings, e.g. converting a list of newtypes to a list of
concrete types.
This function is runtime-representation polymorphic, but the
RuntimeRep type argument is marked as Inferred, meaning
that it is not available for visible type application. This means
the typechecker will accept coerce @Int @Age 42.
fromIntegral :: (Integral a, Num b) => a -> b #
general coercion from integral types
realToFrac :: (Real a, Fractional b) => a -> b #
general coercion to fractional types
guard :: Alternative f => Bool -> f () #
Conditional failure of Alternative computations. Defined by
guard True =pure() guard False =empty
Examples
Common uses of guard include conditionally signaling an error in
an error monad and conditionally rejecting the current choice in an
Alternative-based parser.
As an example of signaling an error in the error monad Maybe,
consider a safe division function safeDiv x y that returns
Nothing when the denominator y is zero and Just (x `div`
y)
>>>safeDiv 4 0Nothing
>>>safeDiv 4 2Just 2
A definition of safeDiv using guards, but not guard:
safeDiv :: Int -> Int -> Maybe Int
safeDiv x y | y /= 0 = Just (x `div` y)
| otherwise = Nothing
A definition of safeDiv using guard and Monad do-notation:
safeDiv :: Int -> Int -> Maybe Int safeDiv x y = do guard (y /= 0) return (x `div` y)
The IsList class and its methods are intended to be used in
conjunction with the OverloadedLists extension.
Since: base-4.7.0.0
Methods
The fromList function constructs the structure l from the given
list of Item l
Instances
join :: Monad m => m (m a) -> m a #
The join function is the conventional monad join operator. It
is used to remove one level of monadic structure, projecting its
bound argument into the outer level.
'join bssdo expression
do bs <- bss bs
Examples
A common use of join is to run an IO computation returned from
an STM transaction, since STM transactions
can't perform IO directly. Recall that
atomically :: STM a -> IO a
is used to run STM transactions atomically. So, by
specializing the types of atomically and join to
atomically:: STM (IO b) -> IO (IO b)join:: IO (IO b) -> IO b
we can compose them as
join.atomically:: STM (IO b) -> IO b
The Bounded class is used to name the upper and lower limits of a
type. Ord is not a superclass of Bounded since types that are not
totally ordered may also have upper and lower bounds.
The Bounded class may be derived for any enumeration type;
minBound is the first constructor listed in the data declaration
and maxBound is the last.
Bounded may also be derived for single-constructor datatypes whose
constituent types are in Bounded.
Instances
Class Enum defines operations on sequentially ordered types.
The enumFrom... methods are used in Haskell's translation of
arithmetic sequences.
Instances of Enum may be derived for any enumeration type (types
whose constructors have no fields). The nullary constructors are
assumed to be numbered left-to-right by fromEnum from 0 through n-1.
See Chapter 10 of the Haskell Report for more details.
For any type that is an instance of class Bounded as well as Enum,
the following should hold:
- The calls
succmaxBoundpredminBound fromEnumandtoEnumshould give a runtime error if the result value is not representable in the result type. For example,toEnum7 ::BoolenumFromandenumFromThenshould be defined with an implicit bound, thus:
enumFrom x = enumFromTo x maxBound
enumFromThen x y = enumFromThenTo x y bound
where
bound | fromEnum y >= fromEnum x = maxBound
| otherwise = minBoundMethods
the successor of a value. For numeric types, succ adds 1.
the predecessor of a value. For numeric types, pred subtracts 1.
Convert from an Int.
Convert to an Int.
It is implementation-dependent what fromEnum returns when
applied to a value that is too large to fit in an Int.
Used in Haskell's translation of [n..] with [n..] = enumFrom n,
a possible implementation being enumFrom n = n : enumFrom (succ n).
For example:
enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]
enumFromThen :: a -> a -> [a] #
Used in Haskell's translation of [n,n'..]
with [n,n'..] = enumFromThen n n', a possible implementation being
enumFromThen n n' = n : n' : worker (f x) (f x n'),
worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
For example:
enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]
enumFromTo :: a -> a -> [a] #
Used in Haskell's translation of [n..m] with
[n..m] = enumFromTo n m, a possible implementation being
enumFromTo n m
| n <= m = n : enumFromTo (succ n) m
| otherwise = [].
For example:
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromThenTo :: a -> a -> a -> [a] #
Used in Haskell's translation of [n,n'..m] with
[n,n'..m] = enumFromThenTo n n' m, a possible implementation
being enumFromThenTo n n' m = worker (f x) (c x) n m,
x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0)
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y and
worker s c v m
| c v m = v : worker s c (s v) m
| otherwise = []
For example:
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
The Eq class defines equality (==) and inequality (/=).
All the basic datatypes exported by the Prelude are instances of Eq,
and Eq may be derived for any datatype whose constituents are also
instances of Eq.
The Haskell Report defines no laws for Eq. However, instances are
encouraged to follow these properties:
Instances
class Fractional a => Floating a where #
Trigonometric and hyperbolic functions and related functions.
The Haskell Report defines no laws for Floating. However, (, +)(
and *)exp are customarily expected to define an exponential field and have
the following properties:
exp (a + b)=exp a * exp bexp (fromInteger 0)=fromInteger 1
Minimal complete definition
pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh
Instances
class Num a => Fractional a where #
Fractional numbers, supporting real division.
The Haskell Report defines no laws for Fractional. However, ( and
+)( are customarily expected to define a division ring and have the
following properties:*)
recipgives the multiplicative inversex * recip x=recip x * x=fromInteger 1
Note that it isn't customarily expected that a type instance of
Fractional implement a field. However, all instances in base do.
Minimal complete definition
fromRational, (recip | (/))
Methods
Fractional division.
Reciprocal fraction.
fromRational :: Rational -> a #
Conversion from a Rational (that is Ratio IntegerfromRational
to a value of type Rational, so such literals have type
(.Fractional a) => a
Instances
| Fractional Number | |
| Fractional CDouble | |
| Fractional CFloat | |
| Fractional Half | |
| Fractional Scientific | WARNING: These methods also compute
|
Defined in Data.Scientific Methods (/) :: Scientific -> Scientific -> Scientific # recip :: Scientific -> Scientific # fromRational :: Rational -> Scientific # | |
| Fractional DiffTime | |
| Fractional NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods (/) :: NominalDiffTime -> NominalDiffTime -> NominalDiffTime # recip :: NominalDiffTime -> NominalDiffTime # fromRational :: Rational -> NominalDiffTime # | |
| RealFloat a => Fractional (Complex a) | Since: base-2.1 |
| Fractional a => Fractional (Identity a) | Since: base-4.9.0.0 |
| Fractional a => Fractional (Down a) | Since: base-4.14.0.0 |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| HasResolution a => Fractional (Fixed a) | Since: base-2.1 |
| Fractional a => Fractional (Op a b) | |
| Fractional a => Fractional (Const a b) | Since: base-4.9.0.0 |
| Fractional a => Fractional (Tagged s a) | |
class (Real a, Enum a) => Integral a where #
Integral numbers, supporting integer division.
The Haskell Report defines no laws for Integral. However, Integral
instances are customarily expected to define a Euclidean domain and have the
following properties for the div/mod and quot/rem pairs, given
suitable Euclidean functions f and g:
x=y * quot x y + rem x ywithrem x y=fromInteger 0org (rem x y)<g yx=y * div x y + mod x ywithmod x y=fromInteger 0orf (mod x y)<f y
An example of a suitable Euclidean function, for Integer's instance, is
abs.
Methods
quot :: a -> a -> a infixl 7 #
integer division truncated toward zero
integer remainder, satisfying
(x `quot` y)*y + (x `rem` y) == x
integer division truncated toward negative infinity
integer modulus, satisfying
(x `div` y)*y + (x `mod` y) == x
conversion to Integer
Instances
class Applicative m => Monad (m :: Type -> Type) where #
The Monad class defines the basic operations over a monad,
a concept from a branch of mathematics known as category theory.
From the perspective of a Haskell programmer, however, it is best to
think of a monad as an abstract datatype of actions.
Haskell's do expressions provide a convenient syntax for writing
monadic expressions.
Instances of Monad should satisfy the following:
- Left identity
returna>>=k = k a- Right identity
m>>=return= m- Associativity
m>>=(\x -> k x>>=h) = (m>>=k)>>=h
Furthermore, the Monad and Applicative operations should relate as follows:
The above laws imply:
and that pure and (<*>) satisfy the applicative functor laws.
The instances of Monad for lists, Maybe and IO
defined in the Prelude satisfy these laws.
Minimal complete definition
Methods
(>>=) :: m a -> (a -> m b) -> m b infixl 1 #
Sequentially compose two actions, passing any value produced by the first as an argument to the second.
'as ' can be understood as the >>= bsdo expression
do a <- as bs a
(>>) :: m a -> m b -> m b infixl 1 #
Sequentially compose two actions, discarding any value produced by the first, like sequencing operators (such as the semicolon) in imperative languages.
'as ' can be understood as the >> bsdo expression
do as bs
Inject a value into the monadic type.
Instances
| Monad IResult | |
| Monad Parser | |
| Monad Result | |
| Monad Graph |
|
| Monad List | |
| Monad Extended | |
| Monad Minimum | |
| Monad NonNegative | |
Defined in Algebra.Graph.Label Methods (>>=) :: NonNegative a -> (a -> NonNegative b) -> NonNegative b # (>>) :: NonNegative a -> NonNegative b -> NonNegative b # return :: a -> NonNegative a # | |
| Monad Complex | Since: base-4.9.0.0 |
| Monad Identity | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| Monad Down | Since: base-4.11.0.0 |
| Monad First | Since: base-4.9.0.0 |
| Monad Last | Since: base-4.9.0.0 |
| Monad Max | Since: base-4.9.0.0 |
| Monad Min | Since: base-4.9.0.0 |
| Monad Dual | Since: base-4.8.0.0 |
| Monad Product | Since: base-4.8.0.0 |
| Monad Sum | Since: base-4.8.0.0 |
| Monad STM | Since: base-4.3.0.0 |
| Monad Par1 | Since: base-4.9.0.0 |
| Monad P | Since: base-2.1 |
| Monad ReadP | Since: base-2.1 |
| Monad ReadPrec | Since: base-2.1 |
| Monad Get | |
| Monad PutM | |
| Monad Put | |
| Monad Seq | |
| Monad Tree | |
| Monad CryptoFailable | |
Defined in Crypto.Error.Types Methods (>>=) :: CryptoFailable a -> (a -> CryptoFailable b) -> CryptoFailable b # (>>) :: CryptoFailable a -> CryptoFailable b -> CryptoFailable b # return :: a -> CryptoFailable a # | |
| Monad DNonEmpty | |
| Monad DList | |
| Monad IO | Since: base-2.1 |
| Monad ParserM | |
| Monad ParserResult | |
Defined in Options.Applicative.Types Methods (>>=) :: ParserResult a -> (a -> ParserResult b) -> ParserResult b # (>>) :: ParserResult a -> ParserResult b -> ParserResult b # return :: a -> ParserResult a # | |
| Monad ReadM | |
| Monad Array | |
| Monad SmallArray | |
Defined in Data.Primitive.SmallArray Methods (>>=) :: SmallArray a -> (a -> SmallArray b) -> SmallArray b # (>>) :: SmallArray a -> SmallArray b -> SmallArray b # return :: a -> SmallArray a # | |
| Monad Q | |
| Monad Vector | |
| Monad Id | |
| Monad Stream | |
| Monad NonEmpty | Since: base-4.9.0.0 |
| Monad Maybe | Since: base-2.1 |
| Monad Solo | Since: base-4.15 |
| Monad [] | Since: base-2.1 |
| Monad (Parser i) | |
| Monad m => Monad (WrappedMonad m) | Since: base-4.7.0.0 |
Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b # (>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # return :: a -> WrappedMonad m a # | |
| ArrowApply a => Monad (ArrowMonad a) | Since: base-2.1 |
Defined in Control.Arrow Methods (>>=) :: ArrowMonad a a0 -> (a0 -> ArrowMonad a b) -> ArrowMonad a b # (>>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # return :: a0 -> ArrowMonad a a0 # | |
| Monad (ST s) | Since: base-2.1 |
| Monad (Either e) | Since: base-4.4.0.0 |
| Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Monad (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Monad (ST s) | Since: base-2.1 |
| Monad (Decoder s) | Since: cborg-0.2.0.0 |
| Monad (IncrementalDecoder s) | |
| Monad (SetM s) | |
| Functor f => Monad (Free f) | |
| Monad (Lint s) Source # | |
| Monad m => Monad (WithStringContextT m) Source # | |
Defined in Nix.String Methods (>>=) :: WithStringContextT m a -> (a -> WithStringContextT m b) -> WithStringContextT m b # (>>) :: WithStringContextT m a -> WithStringContextT m b -> WithStringContextT m b # return :: a -> WithStringContextT m a # | |
| Monad (LogicT m) | |
| Semigroup a => Monad (These a) | |
| Monad (IParser t) | |
| Semigroup a => Monad (These a) | |
| Monad m => Monad (ListT m) | |
| Monad m => Monad (MaybeT m) | |
| Monoid a => Monad ((,) a) | Since: base-4.9.0.0 |
| Monad m => Monad (Kleisli m a) | Since: base-4.14.0.0 |
| Monad f => Monad (Ap f) | Since: base-4.12.0.0 |
| Monad f => Monad (Alt f) | Since: base-4.8.0.0 |
| Monad f => Monad (Rec1 f) | Since: base-4.9.0.0 |
| (Applicative f, Monad f) => Monad (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMissing f x a -> (a -> WhenMissing f x b) -> WhenMissing f x b # (>>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # return :: a -> WhenMissing f x a # | |
| (Functor f, Monad m) => Monad (FreeT f m) | |
| Monad m => Monad (FreshIdT i m) Source # | |
| Monad m => Monad (StandardTF r m) Source # | |
Defined in Nix.Standard Methods (>>=) :: StandardTF r m a -> (a -> StandardTF r m b) -> StandardTF r m b # (>>) :: StandardTF r m a -> StandardTF r m b -> StandardTF r m b # return :: a -> StandardTF r m a # | |
| Monad (t (Fix1 t)) => Monad (Fix1 t) Source # | |
| Monad (Tagged s) | |
| (Monoid w, Functor m, Monad m) => Monad (AccumT w m) | |
| (Monad m, Error e) => Monad (ErrorT e m) | |
| Monad m => Monad (ExceptT e m) | |
| Monad m => Monad (IdentityT m) | |
| Monad m => Monad (ReaderT r m) | |
| Monad m => Monad (SelectT r m) | |
| Monad m => Monad (StateT s m) | |
| Monad m => Monad (StateT s m) | |
| Monad m => Monad (WriterT w m) | |
| (Monoid w, Monad m) => Monad (WriterT w m) | |
| (Monoid w, Monad m) => Monad (WriterT w m) | |
| (Monoid a, Monoid b) => Monad ((,,) a b) | Since: base-4.14.0.0 |
| (Monad f, Monad g) => Monad (Product f g) | Since: base-4.9.0.0 |
| (Monad f, Monad g) => Monad (f :*: g) | Since: base-4.9.0.0 |
| Monad (Cokleisli w a) | |
| (Monad f, Applicative f) => Monad (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods (>>=) :: WhenMatched f x y a -> (a -> WhenMatched f x y b) -> WhenMatched f x y b # (>>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # return :: a -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Monad (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMissing f k x a -> (a -> WhenMissing f k x b) -> WhenMissing f k x b # (>>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # return :: a -> WhenMissing f k x a # | |
| Monad (t (Fix1T t m) m) => Monad (Fix1T t m) Source # | |
| Stream s => Monad (ParsecT e s m) |
|
| Monad (ContT r m) | |
| (Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c) | Since: base-4.14.0.0 |
| Monad ((->) r) | Since: base-2.1 |
| Monad f => Monad (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Monad (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods (>>=) :: WhenMatched f k x y a -> (a -> WhenMatched f k x y b) -> WhenMatched f k x y b # (>>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # return :: a -> WhenMatched f k x y a # | |
| Monad m => Monad (RWST r w s m) | |
| (Monoid w, Monad m) => Monad (RWST r w s m) | |
| (Monoid w, Monad m) => Monad (RWST r w s m) | |
| Monad state => Monad (Builder collection mutCollection step state err) | |
Defined in Basement.MutableBuilder Methods (>>=) :: Builder collection mutCollection step state err a -> (a -> Builder collection mutCollection step state err b) -> Builder collection mutCollection step state err b # (>>) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err b # return :: a -> Builder collection mutCollection step state err a # | |
class Functor (f :: Type -> Type) where #
A type f is a Functor if it provides a function fmap which, given any types a and b
lets you apply any function from (a -> b) to turn an f a into an f b, preserving the
structure of f. Furthermore f needs to adhere to the following:
Note, that the second law follows from the free theorem of the type fmap and
the first law, so you need only check that the former condition holds.
Minimal complete definition
Methods
fmap :: (a -> b) -> f a -> f b #
fmap is used to apply a function of type (a -> b) to a value of type f a,
where f is a functor, to produce a value of type f b.
Note that for any type constructor with more than one parameter (e.g., Either),
only the last type parameter can be modified with fmap (e.g., b in `Either a b`).
Some type constructors with two parameters or more have a Bifunctor
Examples
Convert from a Maybe IntMaybe String
using show:
>>>fmap show NothingNothing>>>fmap show (Just 3)Just "3"
Convert from an Either Int IntEither Int String using show:
>>>fmap show (Left 17)Left 17>>>fmap show (Right 17)Right "17"
Double each element of a list:
>>>fmap (*2) [1,2,3][2,4,6]
Apply even to the second element of a pair:
>>>fmap even (2,2)(2,True)
It may seem surprising that the function is only applied to the last element of the tuple
compared to the list example above which applies it to every element in the list.
To understand, remember that tuples are type constructors with multiple type parameters:
a tuple of 3 elements (a,b,c) can also be written (,,) a b c and its Functor instance
is defined for Functor ((,,) a b) (i.e., only the third parameter is free to be mapped over
with fmap).
It explains why fmap can be used with tuples containing values of different types as in the
following example:
>>>fmap even ("hello", 1.0, 4)("hello",1.0,True)
Instances
Basic numeric class.
The Haskell Report defines no laws for Num. However, ( and +)( are
customarily expected to define a ring and have the following properties:*)
- Associativity of
(+) (x + y) + z=x + (y + z)- Commutativity of
(+) x + y=y + xfromInteger0x + fromInteger 0=xnegategives the additive inversex + negate x=fromInteger 0- Associativity of
(*) (x * y) * z=x * (y * z)fromInteger1x * fromInteger 1=xandfromInteger 1 * x=x- Distributivity of
(with respect to*)(+) a * (b + c)=(a * b) + (a * c)and(b + c) * a=(b * a) + (c * a)
Note that it isn't customarily expected that a type instance of both Num
and Ord implement an ordered ring. Indeed, in base only Integer and
Rational do.
Methods
Unary negation.
Absolute value.
Sign of a number.
The functions abs and signum should satisfy the law:
abs x * signum x == x
For real numbers, the signum is either -1 (negative), 0 (zero)
or 1 (positive).
fromInteger :: Integer -> a #
Conversion from an Integer.
An integer literal represents the application of the function
fromInteger to the appropriate value of type Integer,
so such literals have type (.Num a) => a
Instances
The Ord class is used for totally ordered datatypes.
Instances of Ord can be derived for any user-defined datatype whose
constituent types are in Ord. The declared order of the constructors in
the data declaration determines the ordering in derived Ord instances. The
Ordering datatype allows a single comparison to determine the precise
ordering of two objects.
Ord, as defined by the Haskell report, implements a total order and has the
following properties:
- Comparability
x <= y || y <= x=True- Transitivity
- if
x <= y && y <= z=True, thenx <= z=True - Reflexivity
x <= x=True- Antisymmetry
- if
x <= y && y <= x=True, thenx == y=True
The following operator interactions are expected to hold:
x >= y=y <= xx < y=x <= y && x /= yx > y=y < xx < y=compare x y == LTx > y=compare x y == GTx == y=compare x y == EQmin x y == if x <= y then x else y=Truemax x y == if x >= y then x else y=True
Note that (7.) and (8.) do not require min and max to return either of
their arguments. The result is merely required to equal one of the
arguments in terms of (==).
Minimal complete definition: either compare or <=.
Using compare can be more efficient for complex types.
Methods
compare :: a -> a -> Ordering #
(<) :: a -> a -> Bool infix 4 #
(<=) :: a -> a -> Bool infix 4 #
(>) :: a -> a -> Bool infix 4 #
Instances
Parsing of Strings, producing values.
Derived instances of Read make the following assumptions, which
derived instances of Show obey:
- If the constructor is defined to be an infix operator, then the
derived
Readinstance will parse only infix applications of the constructor (not the prefix form). - Associativity is not used to reduce the occurrence of parentheses, although precedence may be.
- If the constructor is defined using record syntax, the derived
Readwill parse only the record-syntax form, and furthermore, the fields must be given in the same order as the original declaration. - The derived
Readinstance allows arbitrary Haskell whitespace between tokens of the input string. Extra parentheses are also allowed.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Read in Haskell 2010 is equivalent to
instance (Read a) => Read (Tree a) where
readsPrec d r = readParen (d > app_prec)
(\r -> [(Leaf m,t) |
("Leaf",s) <- lex r,
(m,t) <- readsPrec (app_prec+1) s]) r
++ readParen (d > up_prec)
(\r -> [(u:^:v,w) |
(u,s) <- readsPrec (up_prec+1) r,
(":^:",t) <- lex s,
(v,w) <- readsPrec (up_prec+1) t]) r
where app_prec = 10
up_prec = 5Note that right-associativity of :^: is unused.
The derived instance in GHC is equivalent to
instance (Read a) => Read (Tree a) where
readPrec = parens $ (prec app_prec $ do
Ident "Leaf" <- lexP
m <- step readPrec
return (Leaf m))
+++ (prec up_prec $ do
u <- step readPrec
Symbol ":^:" <- lexP
v <- step readPrec
return (u :^: v))
where app_prec = 10
up_prec = 5
readListPrec = readListPrecDefaultWhy do both readsPrec and readPrec exist, and why does GHC opt to
implement readPrec in derived Read instances instead of readsPrec?
The reason is that readsPrec is based on the ReadS type, and although
ReadS is mentioned in the Haskell 2010 Report, it is not a very efficient
parser data structure.
readPrec, on the other hand, is based on a much more efficient ReadPrec
datatype (a.k.a "new-style parsers"), but its definition relies on the use
of the RankNTypes language extension. Therefore, readPrec (and its
cousin, readListPrec) are marked as GHC-only. Nevertheless, it is
recommended to use readPrec instead of readsPrec whenever possible
for the efficiency improvements it brings.
As mentioned above, derived Read instances in GHC will implement
readPrec instead of readsPrec. The default implementations of
readsPrec (and its cousin, readList) will simply use readPrec under
the hood. If you are writing a Read instance by hand, it is recommended
to write it like so:
instanceReadT wherereadPrec= ...readListPrec=readListPrecDefault
Instances
class (Num a, Ord a) => Real a where #
Methods
toRational :: a -> Rational #
the rational equivalent of its real argument with full precision
Instances
class (RealFrac a, Floating a) => RealFloat a where #
Efficient, machine-independent access to the components of a floating-point number.
Minimal complete definition
floatRadix, floatDigits, floatRange, decodeFloat, encodeFloat, isNaN, isInfinite, isDenormalized, isNegativeZero, isIEEE
Methods
floatRadix :: a -> Integer #
a constant function, returning the radix of the representation
(often 2)
floatDigits :: a -> Int #
a constant function, returning the number of digits of
floatRadix in the significand
floatRange :: a -> (Int, Int) #
a constant function, returning the lowest and highest values the exponent may assume
decodeFloat :: a -> (Integer, Int) #
The function decodeFloat applied to a real floating-point
number returns the significand expressed as an Integer and an
appropriately scaled exponent (an Int). If decodeFloat x(m,n), then x is equal in value to m*b^^n, where b
is the floating-point radix, and furthermore, either m and n
are both zero or else b^(d-1) <= , where abs m < b^dd is
the value of floatDigits xdecodeFloat 0 = (0,0)decodeFloat (-0.0) = (0,0)decodeFloat xisNaN xisInfinite xTrue.
encodeFloat :: Integer -> Int -> a #
encodeFloat performs the inverse of decodeFloat in the
sense that for finite x with the exception of -0.0,
uncurry encodeFloat (decodeFloat x) = xencodeFloat m nm*b^^n (or ±Infinity if overflow
occurs); usually the closer, but if m contains too many bits,
the result may be rounded in the wrong direction.
True if the argument is an IEEE "not-a-number" (NaN) value
isInfinite :: a -> Bool #
True if the argument is an IEEE infinity or negative infinity
isDenormalized :: a -> Bool #
True if the argument is too small to be represented in
normalized format
isNegativeZero :: a -> Bool #
True if the argument is an IEEE negative zero
True if the argument is an IEEE floating point number
a version of arctangent taking two real floating-point arguments.
For real floating x and y, atan2 y x(x,y). atan2 y x-pi,
pi]. It follows the Common Lisp semantics for the origin when
signed zeroes are supported. atan2 y 1y in a type
that is RealFloat, should return the same value as atan yatan2 is provided, but implementors
can provide a more accurate implementation.
Instances
class (Real a, Fractional a) => RealFrac a where #
Extracting components of fractions.
Minimal complete definition
Methods
properFraction :: Integral b => a -> (b, a) #
The function properFraction takes a real fractional number x
and returns a pair (n,f) such that x = n+f, and:
nis an integral number with the same sign asx; andfis a fraction with the same type and sign asx, and with absolute value less than1.
The default definitions of the ceiling, floor, truncate
and round functions are in terms of properFraction.
truncate :: Integral b => a -> b #
truncate xx between zero and x
round :: Integral b => a -> b #
round xx;
the even integer if x is equidistant between two integers
ceiling :: Integral b => a -> b #
ceiling xx
floor :: Integral b => a -> b #
floor xx
Instances
| RealFrac Number | |
| RealFrac CDouble | |
| RealFrac CFloat | |
| RealFrac Half | |
| RealFrac Scientific | WARNING: the methods of the |
Defined in Data.Scientific Methods properFraction :: Integral b => Scientific -> (b, Scientific) # truncate :: Integral b => Scientific -> b # round :: Integral b => Scientific -> b # ceiling :: Integral b => Scientific -> b # floor :: Integral b => Scientific -> b # | |
| RealFrac DiffTime | |
| RealFrac NominalDiffTime | |
Defined in Data.Time.Clock.Internal.NominalDiffTime Methods properFraction :: Integral b => NominalDiffTime -> (b, NominalDiffTime) # truncate :: Integral b => NominalDiffTime -> b # round :: Integral b => NominalDiffTime -> b # ceiling :: Integral b => NominalDiffTime -> b # floor :: Integral b => NominalDiffTime -> b # | |
| RealFrac a => RealFrac (Identity a) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Down a) | Since: base-4.14.0.0 |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| HasResolution a => RealFrac (Fixed a) | Since: base-2.1 |
| RealFrac a => RealFrac (Const a b) | Since: base-4.9.0.0 |
| RealFrac a => RealFrac (Tagged s a) | |
Conversion of values to readable Strings.
Derived instances of Show have the following properties, which
are compatible with derived instances of Read:
- The result of
showis a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used. - If the constructor is defined to be an infix operator, then
showsPrecwill produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
xis less thand(associativity is ignored). Thus, ifdis0then the result is never surrounded in parentheses; ifdis11it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
showwill produce the record-syntax form, with the fields given in the same order as the original declaration.
For example, given the declarations
infixr 5 :^: data Tree a = Leaf a | Tree a :^: Tree a
the derived instance of Show is equivalent to
instance (Show a) => Show (Tree a) where
showsPrec d (Leaf m) = showParen (d > app_prec) $
showString "Leaf " . showsPrec (app_prec+1) m
where app_prec = 10
showsPrec d (u :^: v) = showParen (d > up_prec) $
showsPrec (up_prec+1) u .
showString " :^: " .
showsPrec (up_prec+1) v
where up_prec = 5Note that right-associativity of :^: is ignored. For example,
show(Leaf 1 :^: Leaf 2 :^: Leaf 3)"Leaf 1 :^: (Leaf 2 :^: Leaf 3)".
Instances
The class Typeable allows a concrete representation of a type to
be calculated.
Minimal complete definition
typeRep#
class Monad m => MonadFail (m :: Type -> Type) where #
When a value is bound in do-notation, the pattern on the left
hand side of <- might not match. In this case, this class
provides a function to recover.
A Monad without a MonadFail instance may only be used in conjunction
with pattern that always match, such as newtypes, tuples, data types with
only a single data constructor, and irrefutable patterns (~pat).
Instances of MonadFail should satisfy the following law: fail s should
be a left zero for >>=,
fail s >>= f = fail s
If your Monad is also MonadPlus, a popular definition is
fail _ = mzero
Since: base-4.9.0.0
Instances
Class for string-like datastructures; used by the overloaded string extension (-XOverloadedStrings in GHC).
Methods
fromString :: String -> a #
Instances
class Functor f => Applicative (f :: Type -> Type) where #
A functor with application, providing operations to
A minimal complete definition must include implementations of pure
and of either <*> or liftA2. If it defines both, then they must behave
the same as their default definitions:
(<*>) =liftA2id
liftA2f x y = f<$>x<*>y
Further, any definition must satisfy the following:
- Identity
pureid<*>v = v- Composition
pure(.)<*>u<*>v<*>w = u<*>(v<*>w)- Homomorphism
puref<*>purex =pure(f x)- Interchange
u
<*>purey =pure($y)<*>u
The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:
As a consequence of these laws, the Functor instance for f will satisfy
It may be useful to note that supposing
forall x y. p (q x y) = f x . g y
it follows from the above that
liftA2p (liftA2q u v) =liftA2f u .liftA2g v
If f is also a Monad, it should satisfy
(which implies that pure and <*> satisfy the applicative functor laws).
Methods
Lift a value.
(<*>) :: f (a -> b) -> f a -> f b infixl 4 #
Sequential application.
A few functors support an implementation of <*> that is more
efficient than the default one.
Example
Used in combination with (, <$>)( can be used to build a record.<*>)
>>>data MyState = MyState {arg1 :: Foo, arg2 :: Bar, arg3 :: Baz}
>>>produceFoo :: Applicative f => f Foo
>>>produceBar :: Applicative f => f Bar>>>produceBaz :: Applicative f => f Baz
>>>mkState :: Applicative f => f MyState>>>mkState = MyState <$> produceFoo <*> produceBar <*> produceBaz
liftA2 :: (a -> b -> c) -> f a -> f b -> f c #
Lift a binary function to actions.
Some functors support an implementation of liftA2 that is more
efficient than the default one. In particular, if fmap is an
expensive operation, it is likely better to use liftA2 than to
fmap over the structure and then use <*>.
This became a typeclass method in 4.10.0.0. Prior to that, it was
a function defined in terms of <*> and fmap.
Example
>>>liftA2 (,) (Just 3) (Just 5)Just (3,5)
(*>) :: f a -> f b -> f b infixl 4 #
Sequence actions, discarding the value of the first argument.
Examples
If used in conjunction with the Applicative instance for Maybe,
you can chain Maybe computations, with a possible "early return"
in case of Nothing.
>>>Just 2 *> Just 3Just 3
>>>Nothing *> Just 3Nothing
Of course a more interesting use case would be to have effectful computations instead of just returning pure values.
>>>import Data.Char>>>import Text.ParserCombinators.ReadP>>>let p = string "my name is " *> munch1 isAlpha <* eof>>>readP_to_S p "my name is Simon"[("Simon","")]
(<*) :: f a -> f b -> f a infixl 4 #
Sequence actions, discarding the value of the second argument.
Instances
| Applicative IResult | |
| Applicative Parser | |
| Applicative Result | |
| Applicative Graph |
|
| Applicative List | |
| Applicative Extended | |
| Applicative Minimum | |
| Applicative NonNegative | |
Defined in Algebra.Graph.Label Methods pure :: a -> NonNegative a # (<*>) :: NonNegative (a -> b) -> NonNegative a -> NonNegative b # liftA2 :: (a -> b -> c) -> NonNegative a -> NonNegative b -> NonNegative c # (*>) :: NonNegative a -> NonNegative b -> NonNegative b # (<*) :: NonNegative a -> NonNegative b -> NonNegative a # | |
| Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN
= ZipList (zipWithN f xs1 ... xsN)where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
= ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
= ZipList {getZipList = ["a5","b6b6","c7c7c7"]}Since: base-2.1 |
| Applicative Complex | Since: base-4.9.0.0 |
| Applicative Identity | Since: base-4.8.0.0 |
| Applicative First | Since: base-4.8.0.0 |
| Applicative Last | Since: base-4.8.0.0 |
| Applicative Down | Since: base-4.11.0.0 |
| Applicative First | Since: base-4.9.0.0 |
| Applicative Last | Since: base-4.9.0.0 |
| Applicative Max | Since: base-4.9.0.0 |
| Applicative Min | Since: base-4.9.0.0 |
| Applicative Dual | Since: base-4.8.0.0 |
| Applicative Product | Since: base-4.8.0.0 |
| Applicative Sum | Since: base-4.8.0.0 |
| Applicative STM | Since: base-4.8.0.0 |
| Applicative Par1 | Since: base-4.9.0.0 |
| Applicative P | Since: base-4.5.0.0 |
| Applicative ReadP | Since: base-4.6.0.0 |
| Applicative ReadPrec | Since: base-4.6.0.0 |
| Applicative Get | |
| Applicative PutM | |
| Applicative Put | |
| Applicative Seq | Since: containers-0.5.4 |
| Applicative Tree | |
| Applicative CryptoFailable | |
Defined in Crypto.Error.Types Methods pure :: a -> CryptoFailable a # (<*>) :: CryptoFailable (a -> b) -> CryptoFailable a -> CryptoFailable b # liftA2 :: (a -> b -> c) -> CryptoFailable a -> CryptoFailable b -> CryptoFailable c # (*>) :: CryptoFailable a -> CryptoFailable b -> CryptoFailable b # (<*) :: CryptoFailable a -> CryptoFailable b -> CryptoFailable a # | |
| Applicative DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal | |
| Applicative DList | |
| Applicative IO | Since: base-2.1 |
| Applicative Parser | |
| Applicative ParserM | |
| Applicative ParserResult | |
Defined in Options.Applicative.Types Methods pure :: a -> ParserResult a # (<*>) :: ParserResult (a -> b) -> ParserResult a -> ParserResult b # liftA2 :: (a -> b -> c) -> ParserResult a -> ParserResult b -> ParserResult c # (*>) :: ParserResult a -> ParserResult b -> ParserResult b # (<*) :: ParserResult a -> ParserResult b -> ParserResult a # | |
| Applicative ReadM | |
| Applicative Array | |
| Applicative SmallArray | |
Defined in Data.Primitive.SmallArray Methods pure :: a -> SmallArray a # (<*>) :: SmallArray (a -> b) -> SmallArray a -> SmallArray b # liftA2 :: (a -> b -> c) -> SmallArray a -> SmallArray b -> SmallArray c # (*>) :: SmallArray a -> SmallArray b -> SmallArray b # (<*) :: SmallArray a -> SmallArray b -> SmallArray a # | |
| Applicative Q | |
| Applicative Vector | |
| Applicative Id | |
| Applicative Stream | |
| Applicative NonEmpty | Since: base-4.9.0.0 |
| Applicative Maybe | Since: base-2.1 |
| Applicative Solo | Since: base-4.15 |
| Applicative [] | Since: base-2.1 |
| Applicative (Parser i) | |
| Monad m => Applicative (WrappedMonad m) | Since: base-2.1 |
Defined in Control.Applicative Methods pure :: a -> WrappedMonad m a # (<*>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # liftA2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c # (*>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<*) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a # | |
| Arrow a => Applicative (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow Methods pure :: a0 -> ArrowMonad a a0 # (<*>) :: ArrowMonad a (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # liftA2 :: (a0 -> b -> c) -> ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a c # (*>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # (<*) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a a0 # | |
| Applicative (ST s) | Since: base-2.1 |
| Applicative (Either e) | Since: base-3.0 |
| Applicative (StateL s) | Since: base-4.0 |
| Applicative (StateR s) | Since: base-4.0 |
| Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Applicative (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| Applicative (ST s) | Since: base-4.4.0.0 |
| Applicative (Decoder s) | Since: cborg-0.2.0.0 |
| Applicative (IncrementalDecoder s) | |
Defined in Codec.CBOR.Read Methods pure :: a -> IncrementalDecoder s a # (<*>) :: IncrementalDecoder s (a -> b) -> IncrementalDecoder s a -> IncrementalDecoder s b # liftA2 :: (a -> b -> c) -> IncrementalDecoder s a -> IncrementalDecoder s b -> IncrementalDecoder s c # (*>) :: IncrementalDecoder s a -> IncrementalDecoder s b -> IncrementalDecoder s b # (<*) :: IncrementalDecoder s a -> IncrementalDecoder s b -> IncrementalDecoder s a # | |
| Applicative (SetM s) | |
| Functor f => Applicative (Free f) | |
| Applicative (Lint s) Source # | |
| Applicative (StdCited m) Source # | |
Defined in Nix.Standard | |
| Applicative m => Applicative (WithStringContextT m) Source # | |
Defined in Nix.String Methods pure :: a -> WithStringContextT m a # (<*>) :: WithStringContextT m (a -> b) -> WithStringContextT m a -> WithStringContextT m b # liftA2 :: (a -> b -> c) -> WithStringContextT m a -> WithStringContextT m b -> WithStringContextT m c # (*>) :: WithStringContextT m a -> WithStringContextT m b -> WithStringContextT m b # (<*) :: WithStringContextT m a -> WithStringContextT m b -> WithStringContextT m a # | |
| Applicative (LogicT f) | |
| Semigroup a => Applicative (These a) | |
| Applicative (IParser t) | |
| Semigroup a => Applicative (These a) | |
| Applicative m => Applicative (ListT m) | |
| (Functor m, Monad m) => Applicative (MaybeT m) | |
| Monoid a => Applicative ((,) a) | For tuples, the ("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)Since: base-2.1 |
| Arrow a => Applicative (WrappedArrow a b) | Since: base-2.1 |
Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<*>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (*>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # | |
| Applicative m => Applicative (Kleisli m a) | Since: base-4.14.0.0 |
Defined in Control.Arrow | |
| Monoid m => Applicative (Const m :: Type -> Type) | Since: base-2.0.1 |
| Applicative f => Applicative (Ap f) | Since: base-4.12.0.0 |
| Applicative f => Applicative (Alt f) | Since: base-4.8.0.0 |
| Applicative f => Applicative (Rec1 f) | Since: base-4.9.0.0 |
| Applicative (Mag a b) | |
| Biapplicative p => Applicative (Join p) | |
| (Monoid e, Applicative m) => Applicative (EnvT e m) | |
| (Applicative f, Monad f) => Applicative (WhenMissing f x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMissing f x a # (<*>) :: WhenMissing f x (a -> b) -> WhenMissing f x a -> WhenMissing f x b # liftA2 :: (a -> b -> c) -> WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x c # (*>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # (<*) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x a # | |
| (Functor f, Monad m) => Applicative (FreeT f m) | |
Defined in Control.Monad.Trans.Free | |
| (Generic1 f, Applicative (Rep1 f)) => Applicative (Generically1 f) | |
Defined in GHC.Generics.Generically Methods pure :: a -> Generically1 f a # (<*>) :: Generically1 f (a -> b) -> Generically1 f a -> Generically1 f b # liftA2 :: (a -> b -> c) -> Generically1 f a -> Generically1 f b -> Generically1 f c # (*>) :: Generically1 f a -> Generically1 f b -> Generically1 f b # (<*) :: Generically1 f a -> Generically1 f b -> Generically1 f a # | |
| Applicative (NCited m v) Source # | |
| Applicative m => Applicative (FreshIdT i m) Source # | |
| Monad m => Applicative (StandardTF r m) Source # | |
Defined in Nix.Standard Methods pure :: a -> StandardTF r m a # (<*>) :: StandardTF r m (a -> b) -> StandardTF r m a -> StandardTF r m b # liftA2 :: (a -> b -> c) -> StandardTF r m a -> StandardTF r m b -> StandardTF r m c # (*>) :: StandardTF r m a -> StandardTF r m b -> StandardTF r m b # (<*) :: StandardTF r m a -> StandardTF r m b -> StandardTF r m a # | |
| Applicative (t (Fix1 t)) => Applicative (Fix1 t) Source # | |
| Applicative f => Applicative (Indexing f) | |
| Applicative (Tagged s) | |
| (Monoid w, Functor m, Monad m) => Applicative (AccumT w m) | |
Defined in Control.Monad.Trans.Accum | |
| (Functor m, Monad m) => Applicative (ErrorT e m) | |
Defined in Control.Monad.Trans.Error | |
| (Functor m, Monad m) => Applicative (ExceptT e m) | |
Defined in Control.Monad.Trans.Except | |
| Applicative m => Applicative (IdentityT m) | |
Defined in Control.Monad.Trans.Identity | |
| Applicative m => Applicative (ReaderT r m) | |
Defined in Control.Monad.Trans.Reader | |
| (Functor m, Monad m) => Applicative (SelectT r m) | |
Defined in Control.Monad.Trans.Select | |
| (Functor m, Monad m) => Applicative (StateT s m) | |
Defined in Control.Monad.Trans.State.Lazy | |
| (Functor m, Monad m) => Applicative (StateT s m) | |
Defined in Control.Monad.Trans.State.Strict | |
| (Functor m, Monad m) => Applicative (WriterT w m) | |
Defined in Control.Monad.Trans.Writer.CPS | |
| (Monoid w, Applicative m) => Applicative (WriterT w m) | |
Defined in Control.Monad.Trans.Writer.Lazy | |
| (Monoid w, Applicative m) => Applicative (WriterT w m) | |
Defined in Control.Monad.Trans.Writer.Strict | |
| Monoid a => Applicative (Constant a :: Type -> Type) | |
Defined in Data.Functor.Constant | |
| (Monoid a, Monoid b) => Applicative ((,,) a b) | Since: base-4.14.0.0 |
| (Applicative f, Applicative g) => Applicative (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product | |
| (Applicative f, Applicative g) => Applicative (f :*: g) | Since: base-4.9.0.0 |
| Monoid c => Applicative (K1 i c :: Type -> Type) | Since: base-4.12.0.0 |
| Applicative (Cokleisli w a) | |
Defined in Control.Comonad Methods pure :: a0 -> Cokleisli w a a0 # (<*>) :: Cokleisli w a (a0 -> b) -> Cokleisli w a a0 -> Cokleisli w a b # liftA2 :: (a0 -> b -> c) -> Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a c # (*>) :: Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a b # (<*) :: Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a a0 # | |
| (Monad f, Applicative f) => Applicative (WhenMatched f x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.IntMap.Internal Methods pure :: a -> WhenMatched f x y a # (<*>) :: WhenMatched f x y (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # liftA2 :: (a -> b -> c) -> WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y c # (*>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # (<*) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y a # | |
| (Applicative f, Monad f) => Applicative (WhenMissing f k x) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMissing f k x a # (<*>) :: WhenMissing f k x (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # liftA2 :: (a -> b -> c) -> WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x c # (*>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # (<*) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x a # | |
| Applicative (Cited t f m) Source # | |
Defined in Nix.Cited.Basic | |
| Applicative (t (Fix1T t m) m) => Applicative (Fix1T t m) Source # | |
| Stream s => Applicative (ParsecT e s m) |
|
Defined in Text.Megaparsec.Internal Methods pure :: a -> ParsecT e s m a # (<*>) :: ParsecT e s m (a -> b) -> ParsecT e s m a -> ParsecT e s m b # liftA2 :: (a -> b -> c) -> ParsecT e s m a -> ParsecT e s m b -> ParsecT e s m c # (*>) :: ParsecT e s m a -> ParsecT e s m b -> ParsecT e s m b # (<*) :: ParsecT e s m a -> ParsecT e s m b -> ParsecT e s m a # | |
| Applicative (ContT r m) | |
Defined in Control.Monad.Trans.Cont | |
| (Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c) | Since: base-4.14.0.0 |
Defined in GHC.Base | |
| Applicative ((->) r) | Since: base-2.1 |
| (Applicative f, Applicative g) => Applicative (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Applicative f, Applicative g) => Applicative (f :.: g) | Since: base-4.9.0.0 |
| Applicative f => Applicative (M1 i c f) | Since: base-4.9.0.0 |
| (Monad f, Applicative f) => Applicative (WhenMatched f k x y) | Equivalent to Since: containers-0.5.9 |
Defined in Data.Map.Internal Methods pure :: a -> WhenMatched f k x y a # (<*>) :: WhenMatched f k x y (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # liftA2 :: (a -> b -> c) -> WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y c # (*>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # (<*) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y a # | |
| (Functor m, Monad m) => Applicative (RWST r w s m) | |
Defined in Control.Monad.Trans.RWS.CPS | |
| (Monoid w, Functor m, Monad m) => Applicative (RWST r w s m) | |
Defined in Control.Monad.Trans.RWS.Lazy | |
| (Monoid w, Functor m, Monad m) => Applicative (RWST r w s m) | |
Defined in Control.Monad.Trans.RWS.Strict | |
| Monad state => Applicative (Builder collection mutCollection step state err) | |
Defined in Basement.MutableBuilder Methods pure :: a -> Builder collection mutCollection step state err a # (<*>) :: Builder collection mutCollection step state err (a -> b) -> Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b # liftA2 :: (a -> b -> c) -> Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err c # (*>) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err b # (<*) :: Builder collection mutCollection step state err a -> Builder collection mutCollection step state err b -> Builder collection mutCollection step state err a # | |
class Foldable (t :: TYPE LiftedRep -> Type) where #
The Foldable class represents data structures that can be reduced to a summary value one element at a time. Strict left-associative folds are a good fit for space-efficient reduction, while lazy right-associative folds are a good fit for corecursive iteration, or for folds that short-circuit after processing an initial subsequence of the structure's elements.
Instances can be derived automatically by enabling the DeriveFoldable
extension. For example, a derived instance for a binary tree might be:
{-# LANGUAGE DeriveFoldable #-}
data Tree a = Empty
| Leaf a
| Node (Tree a) a (Tree a)
deriving FoldableA more detailed description can be found in the Overview section of Data.Foldable.
For the class laws see the Laws section of Data.Foldable.
Methods
fold :: Monoid m => t m -> m #
Given a structure with elements whose type is a Monoid, combine them
via the monoid's ( operator. This fold is right-associative and
lazy in the accumulator. When you need a strict left-associative fold,
use <>)foldMap' instead, with id as the map.
Examples
Basic usage:
>>>fold [[1, 2, 3], [4, 5], [6], []][1,2,3,4,5,6]
>>>fold $ Node (Leaf (Sum 1)) (Sum 3) (Leaf (Sum 5))Sum {getSum = 9}
Folds of unbounded structures do not terminate when the monoid's
( operator is strict:<>)
>>>fold (repeat Nothing)* Hangs forever *
Lazy corecursive folds of unbounded structures are fine:
>>>take 12 $ fold $ map (\i -> [i..i+2]) [0..][0,1,2,1,2,3,2,3,4,3,4,5]>>>sum $ take 4000000 $ fold $ map (\i -> [i..i+2]) [0..]2666668666666
foldMap :: Monoid m => (a -> m) -> t a -> m #
Map each element of the structure into a monoid, and combine the
results with (. This fold is right-associative and lazy in the
accumulator. For strict left-associative folds consider <>)foldMap'
instead.
Examples
Basic usage:
>>>foldMap Sum [1, 3, 5]Sum {getSum = 9}
>>>foldMap Product [1, 3, 5]Product {getProduct = 15}
>>>foldMap (replicate 3) [1, 2, 3][1,1,1,2,2,2,3,3,3]
When a Monoid's ( is lazy in its second argument, <>)foldMap can
return a result even from an unbounded structure. For example, lazy
accumulation enables Data.ByteString.Builder to efficiently serialise
large data structures and produce the output incrementally:
>>>import qualified Data.ByteString.Lazy as L>>>import qualified Data.ByteString.Builder as B>>>let bld :: Int -> B.Builder; bld i = B.intDec i <> B.word8 0x20>>>let lbs = B.toLazyByteString $ foldMap bld [0..]>>>L.take 64 lbs"0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24"
foldMap' :: Monoid m => (a -> m) -> t a -> m #
A left-associative variant of foldMap that is strict in the
accumulator. Use this method for strict reduction when partial
results are merged via (.<>)
Examples
Define a Monoid over finite bit strings under xor. Use it to
strictly compute the xor of a list of Int values.
>>>:set -XGeneralizedNewtypeDeriving>>>import Data.Bits (Bits, FiniteBits, xor, zeroBits)>>>import Data.Foldable (foldMap')>>>import Numeric (showHex)>>>>>>newtype X a = X a deriving (Eq, Bounded, Enum, Bits, FiniteBits)>>>instance Bits a => Semigroup (X a) where X a <> X b = X (a `xor` b)>>>instance Bits a => Monoid (X a) where mempty = X zeroBits>>>>>>let bits :: [Int]; bits = [0xcafe, 0xfeed, 0xdeaf, 0xbeef, 0x5411]>>>(\ (X a) -> showString "0x" . showHex a $ "") $ foldMap' X bits"0x42"
Since: base-4.13.0.0
foldr :: (a -> b -> b) -> b -> t a -> b #
Right-associative fold of a structure, lazy in the accumulator.
In the case of lists, foldr, when applied to a binary operator, a
starting value (typically the right-identity of the operator), and a
list, reduces the list using the binary operator, from right to left:
foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
Note that since the head of the resulting expression is produced by an
application of the operator to the first element of the list, given an
operator lazy in its right argument, foldr can produce a terminating
expression from an unbounded list.
For a general Foldable structure this should be semantically identical
to,
foldr f z =foldrf z .toList
Examples
Basic usage:
>>>foldr (||) False [False, True, False]True
>>>foldr (||) False []False
>>>foldr (\c acc -> acc ++ [c]) "foo" ['a', 'b', 'c', 'd']"foodcba"
Infinite structures
⚠️ Applying foldr to infinite structures usually doesn't terminate.
It may still terminate under one of the following conditions:
- the folding function is short-circuiting
- the folding function is lazy on its second argument
Short-circuiting
( short-circuits on ||)True values, so the following terminates
because there is a True value finitely far from the left side:
>>>foldr (||) False (True : repeat False)True
But the following doesn't terminate:
>>>foldr (||) False (repeat False ++ [True])* Hangs forever *
Laziness in the second argument
Applying foldr to infinite structures terminates when the operator is
lazy in its second argument (the initial accumulator is never used in
this case, and so could be left undefined, but [] is more clear):
>>>take 5 $ foldr (\i acc -> i : fmap (+3) acc) [] (repeat 1)[1,4,7,10,13]
foldl' :: (b -> a -> b) -> b -> t a -> b #
Left-associative fold of a structure but with strict application of the operator.
This ensures that each step of the fold is forced to Weak Head Normal
Form before being applied, avoiding the collection of thunks that would
otherwise occur. This is often what you want to strictly reduce a
finite structure to a single strict result (e.g. sum).
For a general Foldable structure this should be semantically identical
to,
foldl' f z =foldl'f z .toList
Since: base-4.6.0.0
List of elements of a structure, from left to right. If the entire list is intended to be reduced via a fold, just fold the structure directly bypassing the list.
Examples
Basic usage:
>>>toList Nothing[]
>>>toList (Just 42)[42]
>>>toList (Left "foo")[]
>>>toList (Node (Leaf 5) 17 (Node Empty 12 (Leaf 8)))[5,17,12,8]
For lists, toList is the identity:
>>>toList [1, 2, 3][1,2,3]
Since: base-4.8.0.0
Test whether the structure is empty. The default implementation is Left-associative and lazy in both the initial element and the accumulator. Thus optimised for structures where the first element can be accessed in constant time. Structures where this is not the case should have a non-default implementation.
Examples
Basic usage:
>>>null []True
>>>null [1]False
null is expected to terminate even for infinite structures.
The default implementation terminates provided the structure
is bounded on the left (there is a leftmost element).
>>>null [1..]False
Since: base-4.8.0.0
Returns the size/length of a finite structure as an Int. The
default implementation just counts elements starting with the leftmost.
Instances for structures that can compute the element count faster
than via element-by-element counting, should provide a specialised
implementation.
Examples
Basic usage:
>>>length []0
>>>length ['a', 'b', 'c']3>>>length [1..]* Hangs forever *
Since: base-4.8.0.0
Instances
| Foldable KeyMap | |
Defined in Data.Aeson.KeyMap Methods fold :: Monoid m => KeyMap m -> m # foldMap :: Monoid m => (a -> m) -> KeyMap a -> m # foldMap' :: Monoid m => (a -> m) -> KeyMap a -> m # foldr :: (a -> b -> b) -> b -> KeyMap a -> b # foldr' :: (a -> b -> b) -> b -> KeyMap a -> b # foldl :: (b -> a -> b) -> b -> KeyMap a -> b # foldl' :: (b -> a -> b) -> b -> KeyMap a -> b # foldr1 :: (a -> a -> a) -> KeyMap a -> a # foldl1 :: (a -> a -> a) -> KeyMap a -> a # elem :: Eq a => a -> KeyMap a -> Bool # maximum :: Ord a => KeyMap a -> a # minimum :: Ord a => KeyMap a -> a # | |
| Foldable IResult | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => IResult m -> m # foldMap :: Monoid m => (a -> m) -> IResult a -> m # foldMap' :: Monoid m => (a -> m) -> IResult a -> m # foldr :: (a -> b -> b) -> b -> IResult a -> b # foldr' :: (a -> b -> b) -> b -> IResult a -> b # foldl :: (b -> a -> b) -> b -> IResult a -> b # foldl' :: (b -> a -> b) -> b -> IResult a -> b # foldr1 :: (a -> a -> a) -> IResult a -> a # foldl1 :: (a -> a -> a) -> IResult a -> a # elem :: Eq a => a -> IResult a -> Bool # maximum :: Ord a => IResult a -> a # minimum :: Ord a => IResult a -> a # | |
| Foldable Result | |
Defined in Data.Aeson.Types.Internal Methods fold :: Monoid m => Result m -> m # foldMap :: Monoid m => (a -> m) -> Result a -> m # foldMap' :: Monoid m => (a -> m) -> Result a -> m # foldr :: (a -> b -> b) -> b -> Result a -> b # foldr' :: (a -> b -> b) -> b -> Result a -> b # foldl :: (b -> a -> b) -> b -> Result a -> b # foldl' :: (b -> a -> b) -> b -> Result a -> b # foldr1 :: (a -> a -> a) -> Result a -> a # foldl1 :: (a -> a -> a) -> Result a -> a # elem :: Eq a => a -> Result a -> Bool # maximum :: Ord a => Result a -> a # minimum :: Ord a => Result a -> a # | |
| Foldable List | |
Defined in Algebra.Graph.Internal Methods fold :: Monoid m => List m -> m # foldMap :: Monoid m => (a -> m) -> List a -> m # foldMap' :: Monoid m => (a -> m) -> List a -> m # foldr :: (a -> b -> b) -> b -> List a -> b # foldr' :: (a -> b -> b) -> b -> List a -> b # foldl :: (b -> a -> b) -> b -> List a -> b # foldl' :: (b -> a -> b) -> b -> List a -> b # foldr1 :: (a -> a -> a) -> List a -> a # foldl1 :: (a -> a -> a) -> List a -> a # elem :: Eq a => a -> List a -> Bool # maximum :: Ord a => List a -> a # | |
| Foldable ZipList | Since: base-4.9.0.0 |
Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # | |
| Foldable Complex | Since: base-4.9.0.0 |
Defined in Data.Complex Methods fold :: Monoid m => Complex m -> m # foldMap :: Monoid m => (a -> m) -> Complex a -> m # foldMap' :: Monoid m => (a -> m) -> Complex a -> m # foldr :: (a -> b -> b) -> b -> Complex a -> b # foldr' :: (a -> b -> b) -> b -> Complex a -> b # foldl :: (b -> a -> b) -> b -> Complex a -> b # foldl' :: (b -> a -> b) -> b -> Complex a -> b # foldr1 :: (a -> a -> a) -> Complex a -> a # foldl1 :: (a -> a -> a) -> Complex a -> a # elem :: Eq a => a -> Complex a -> Bool # maximum :: Ord a => Complex a -> a # minimum :: Ord a => Complex a -> a # | |
| Foldable Identity | Since: base-4.8.0.0 |
Defined in Data.Functor.Identity Methods fold :: Monoid m => Identity m -> m # foldMap :: Monoid m => (a -> m) -> Identity a -> m # foldMap' :: Monoid m => (a -> m) -> Identity a -> m # foldr :: (a -> b -> b) -> b -> Identity a -> b # foldr' :: (a -> b -> b) -> b -> Identity a -> b # foldl :: (b -> a -> b) -> b -> Identity a -> b # foldl' :: (b -> a -> b) -> b -> Identity a -> b # foldr1 :: (a -> a -> a) -> Identity a -> a # foldl1 :: (a -> a -> a) -> Identity a -> a # elem :: Eq a => a -> Identity a -> Bool # maximum :: Ord a => Identity a -> a # minimum :: Ord a => Identity a -> a # | |
| Foldable First | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Down | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # | |
| Foldable First | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Foldable Last | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Foldable Max | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Max m -> m # foldMap :: Monoid m => (a -> m) -> Max a -> m # foldMap' :: Monoid m => (a -> m) -> Max a -> m # foldr :: (a -> b -> b) -> b -> Max a -> b # foldr' :: (a -> b -> b) -> b -> Max a -> b # foldl :: (b -> a -> b) -> b -> Max a -> b # foldl' :: (b -> a -> b) -> b -> Max a -> b # foldr1 :: (a -> a -> a) -> Max a -> a # foldl1 :: (a -> a -> a) -> Max a -> a # elem :: Eq a => a -> Max a -> Bool # maximum :: Ord a => Max a -> a # | |
| Foldable Min | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Min m -> m # foldMap :: Monoid m => (a -> m) -> Min a -> m # foldMap' :: Monoid m => (a -> m) -> Min a -> m # foldr :: (a -> b -> b) -> b -> Min a -> b # foldr' :: (a -> b -> b) -> b -> Min a -> b # foldl :: (b -> a -> b) -> b -> Min a -> b # foldl' :: (b -> a -> b) -> b -> Min a -> b # foldr1 :: (a -> a -> a) -> Min a -> a # foldl1 :: (a -> a -> a) -> Min a -> a # elem :: Eq a => a -> Min a -> Bool # maximum :: Ord a => Min a -> a # | |
| Foldable Dual | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # | |
| Foldable Product | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m # foldMap :: Monoid m => (a -> m) -> Product a -> m # foldMap' :: Monoid m => (a -> m) -> Product a -> m # foldr :: (a -> b -> b) -> b -> Product a -> b # foldr' :: (a -> b -> b) -> b -> Product a -> b # foldl :: (b -> a -> b) -> b -> Product a -> b # foldl' :: (b -> a -> b) -> b -> Product a -> b # foldr1 :: (a -> a -> a) -> Product a -> a # foldl1 :: (a -> a -> a) -> Product a -> a # elem :: Eq a => a -> Product a -> Bool # maximum :: Ord a => Product a -> a # minimum :: Ord a => Product a -> a # | |
| Foldable Sum | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m # foldMap :: Monoid m => (a -> m) -> Sum a -> m # foldMap' :: Monoid m => (a -> m) -> Sum a -> m # foldr :: (a -> b -> b) -> b -> Sum a -> b # foldr' :: (a -> b -> b) -> b -> Sum a -> b # foldl :: (b -> a -> b) -> b -> Sum a -> b # foldl' :: (b -> a -> b) -> b -> Sum a -> b # foldr1 :: (a -> a -> a) -> Sum a -> a # foldl1 :: (a -> a -> a) -> Sum a -> a # elem :: Eq a => a -> Sum a -> Bool # maximum :: Ord a => Sum a -> a # | |
| Foldable Par1 | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Par1 m -> m # foldMap :: Monoid m => (a -> m) -> Par1 a -> m # foldMap' :: Monoid m => (a -> m) -> Par1 a -> m # foldr :: (a -> b -> b) -> b -> Par1 a -> b # foldr' :: (a -> b -> b) -> b -> Par1 a -> b # foldl :: (b -> a -> b) -> b -> Par1 a -> b # foldl' :: (b -> a -> b) -> b -> Par1 a -> b # foldr1 :: (a -> a -> a) -> Par1 a -> a # foldl1 :: (a -> a -> a) -> Par1 a -> a # elem :: Eq a => a -> Par1 a -> Bool # maximum :: Ord a => Par1 a -> a # | |
| Foldable SCC | Since: containers-0.5.9 |
Defined in Data.Graph Methods fold :: Monoid m => SCC m -> m # foldMap :: Monoid m => (a -> m) -> SCC a -> m # foldMap' :: Monoid m => (a -> m) -> SCC a -> m # foldr :: (a -> b -> b) -> b -> SCC a -> b # foldr' :: (a -> b -> b) -> b -> SCC a -> b # foldl :: (b -> a -> b) -> b -> SCC a -> b # foldl' :: (b -> a -> b) -> b -> SCC a -> b # foldr1 :: (a -> a -> a) -> SCC a -> a # foldl1 :: (a -> a -> a) -> SCC a -> a # elem :: Eq a => a -> SCC a -> Bool # maximum :: Ord a => SCC a -> a # | |
| Foldable IntMap | Folds in order of increasing key. |
Defined in Data.IntMap.Internal Methods fold :: Monoid m => IntMap m -> m # foldMap :: Monoid m => (a -> m) -> IntMap a -> m # foldMap' :: Monoid m => (a -> m) -> IntMap a -> m # foldr :: (a -> b -> b) -> b -> IntMap a -> b # foldr' :: (a -> b -> b) -> b -> IntMap a -> b # foldl :: (b -> a -> b) -> b -> IntMap a -> b # foldl' :: (b -> a -> b) -> b -> IntMap a -> b # foldr1 :: (a -> a -> a) -> IntMap a -> a # foldl1 :: (a -> a -> a) -> IntMap a -> a # elem :: Eq a => a -> IntMap a -> Bool # maximum :: Ord a => IntMap a -> a # minimum :: Ord a => IntMap a -> a # | |
| Foldable Digit | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Digit m -> m # foldMap :: Monoid m => (a -> m) -> Digit a -> m # foldMap' :: Monoid m => (a -> m) -> Digit a -> m # foldr :: (a -> b -> b) -> b -> Digit a -> b # foldr' :: (a -> b -> b) -> b -> Digit a -> b # foldl :: (b -> a -> b) -> b -> Digit a -> b # foldl' :: (b -> a -> b) -> b -> Digit a -> b # foldr1 :: (a -> a -> a) -> Digit a -> a # foldl1 :: (a -> a -> a) -> Digit a -> a # elem :: Eq a => a -> Digit a -> Bool # maximum :: Ord a => Digit a -> a # minimum :: Ord a => Digit a -> a # | |
| Foldable Elem | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Elem m -> m # foldMap :: Monoid m => (a -> m) -> Elem a -> m # foldMap' :: Monoid m => (a -> m) -> Elem a -> m # foldr :: (a -> b -> b) -> b -> Elem a -> b # foldr' :: (a -> b -> b) -> b -> Elem a -> b # foldl :: (b -> a -> b) -> b -> Elem a -> b # foldl' :: (b -> a -> b) -> b -> Elem a -> b # foldr1 :: (a -> a -> a) -> Elem a -> a # foldl1 :: (a -> a -> a) -> Elem a -> a # elem :: Eq a => a -> Elem a -> Bool # maximum :: Ord a => Elem a -> a # | |
| Foldable FingerTree | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => FingerTree m -> m # foldMap :: Monoid m => (a -> m) -> FingerTree a -> m # foldMap' :: Monoid m => (a -> m) -> FingerTree a -> m # foldr :: (a -> b -> b) -> b -> FingerTree a -> b # foldr' :: (a -> b -> b) -> b -> FingerTree a -> b # foldl :: (b -> a -> b) -> b -> FingerTree a -> b # foldl' :: (b -> a -> b) -> b -> FingerTree a -> b # foldr1 :: (a -> a -> a) -> FingerTree a -> a # foldl1 :: (a -> a -> a) -> FingerTree a -> a # toList :: FingerTree a -> [a] # null :: FingerTree a -> Bool # length :: FingerTree a -> Int # elem :: Eq a => a -> FingerTree a -> Bool # maximum :: Ord a => FingerTree a -> a # minimum :: Ord a => FingerTree a -> a # sum :: Num a => FingerTree a -> a # product :: Num a => FingerTree a -> a # | |
| Foldable Node | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Node m -> m # foldMap :: Monoid m => (a -> m) -> Node a -> m # foldMap' :: Monoid m => (a -> m) -> Node a -> m # foldr :: (a -> b -> b) -> b -> Node a -> b # foldr' :: (a -> b -> b) -> b -> Node a -> b # foldl :: (b -> a -> b) -> b -> Node a -> b # foldl' :: (b -> a -> b) -> b -> Node a -> b # foldr1 :: (a -> a -> a) -> Node a -> a # foldl1 :: (a -> a -> a) -> Node a -> a # elem :: Eq a => a -> Node a -> Bool # maximum :: Ord a => Node a -> a # | |
| Foldable Seq | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Seq m -> m # foldMap :: Monoid m => (a -> m) -> Seq a -> m # foldMap' :: Monoid m => (a -> m) -> Seq a -> m # foldr :: (a -> b -> b) -> b -> Seq a -> b # foldr' :: (a -> b -> b) -> b -> Seq a -> b # foldl :: (b -> a -> b) -> b -> Seq a -> b # foldl' :: (b -> a -> b) -> b -> Seq a -> b # foldr1 :: (a -> a -> a) -> Seq a -> a # foldl1 :: (a -> a -> a) -> Seq a -> a # elem :: Eq a => a -> Seq a -> Bool # maximum :: Ord a => Seq a -> a # | |
| Foldable ViewL | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewL m -> m # foldMap :: Monoid m => (a -> m) -> ViewL a -> m # foldMap' :: Monoid m => (a -> m) -> ViewL a -> m # foldr :: (a -> b -> b) -> b -> ViewL a -> b # foldr' :: (a -> b -> b) -> b -> ViewL a -> b # foldl :: (b -> a -> b) -> b -> ViewL a -> b # foldl' :: (b -> a -> b) -> b -> ViewL a -> b # foldr1 :: (a -> a -> a) -> ViewL a -> a # foldl1 :: (a -> a -> a) -> ViewL a -> a # elem :: Eq a => a -> ViewL a -> Bool # maximum :: Ord a => ViewL a -> a # minimum :: Ord a => ViewL a -> a # | |
| Foldable ViewR | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => ViewR m -> m # foldMap :: Monoid m => (a -> m) -> ViewR a -> m # foldMap' :: Monoid m => (a -> m) -> ViewR a -> m # foldr :: (a -> b -> b) -> b -> ViewR a -> b # foldr' :: (a -> b -> b) -> b -> ViewR a -> b # foldl :: (b -> a -> b) -> b -> ViewR a -> b # foldl' :: (b -> a -> b) -> b -> ViewR a -> b # foldr1 :: (a -> a -> a) -> ViewR a -> a # foldl1 :: (a -> a -> a) -> ViewR a -> a # elem :: Eq a => a -> ViewR a -> Bool # maximum :: Ord a => ViewR a -> a # minimum :: Ord a => ViewR a -> a # | |
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| Foldable Tree | |
Defined in Data.Tree Methods fold :: Monoid m => Tree m -> m # foldMap :: Monoid m => (a -> m) -> Tree a -> m # foldMap' :: Monoid m => (a -> m) -> Tree a -> m # foldr :: (a -> b -> b) -> b -> Tree a -> b # foldr' :: (a -> b -> b) -> b -> Tree a -> b # foldl :: (b -> a -> b) -> b -> Tree a -> b # foldl' :: (b -> a -> b) -> b -> Tree a -> b # foldr1 :: (a -> a -> a) -> Tree a -> a # foldl1 :: (a -> a -> a) -> Tree a -> a # elem :: Eq a => a -> Tree a -> Bool # maximum :: Ord a => Tree a -> a # | |
| Foldable DNonEmpty | |
Defined in Data.DList.DNonEmpty.Internal Methods fold :: Monoid m => DNonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> DNonEmpty a -> m # foldr :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> DNonEmpty a -> b # foldl :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> DNonEmpty a -> b # foldr1 :: (a -> a -> a) -> DNonEmpty a -> a # foldl1 :: (a -> a -> a) -> DNonEmpty a -> a # toList :: DNonEmpty a -> [a] # length :: DNonEmpty a -> Int # elem :: Eq a => a -> DNonEmpty a -> Bool # maximum :: Ord a => DNonEmpty a -> a # minimum :: Ord a => DNonEmpty a -> a # | |
| Foldable DList | |
Defined in Data.DList.Internal Methods fold :: Monoid m => DList m -> m # foldMap :: Monoid m => (a -> m) -> DList a -> m # foldMap' :: Monoid m => (a -> m) -> DList a -> m # foldr :: (a -> b -> b) -> b -> DList a -> b # foldr' :: (a -> b -> b) -> b -> DList a -> b # foldl :: (b -> a -> b) -> b -> DList a -> b # foldl' :: (b -> a -> b) -> b -> DList a -> b # foldr1 :: (a -> a -> a) -> DList a -> a # foldl1 :: (a -> a -> a) -> DList a -> a # elem :: Eq a => a -> DList a -> Bool # maximum :: Ord a => DList a -> a # minimum :: Ord a => DList a -> a # | |
| Foldable Hashed | |
Defined in Data.Hashable.Class Methods fold :: Monoid m => Hashed m -> m # foldMap :: Monoid m => (a -> m) -> Hashed a -> m # foldMap' :: Monoid m => (a -> m) -> Hashed a -> m # foldr :: (a -> b -> b) -> b -> Hashed a -> b # foldr' :: (a -> b -> b) -> b -> Hashed a -> b # foldl :: (b -> a -> b) -> b -> Hashed a -> b # foldl' :: (b -> a -> b) -> b -> Hashed a -> b # foldr1 :: (a -> a -> a) -> Hashed a -> a # foldl1 :: (a -> a -> a) -> Hashed a -> a # elem :: Eq a => a -> Hashed a -> Bool # maximum :: Ord a => Hashed a -> a # minimum :: Ord a => Hashed a -> a # | |
| Foldable Deeper Source # | |
Defined in Nix.Convert Methods fold :: Monoid m => Deeper m -> m # foldMap :: Monoid m => (a -> m) -> Deeper a -> m # foldMap' :: Monoid m => (a -> m) -> Deeper a -> m # foldr :: (a -> b -> b) -> b -> Deeper a -> b # foldr' :: (a -> b -> b) -> b -> Deeper a -> b # foldl :: (b -> a -> b) -> b -> Deeper a -> b # foldl' :: (b -> a -> b) -> b -> Deeper a -> b # foldr1 :: (a -> a -> a) -> Deeper a -> a # foldl1 :: (a -> a -> a) -> Deeper a -> a # elem :: Eq a => a -> Deeper a -> Bool # maximum :: Ord a => Deeper a -> a # minimum :: Ord a => Deeper a -> a # | |
| Foldable Binding Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => Binding m -> m # foldMap :: Monoid m => (a -> m) -> Binding a -> m # foldMap' :: Monoid m => (a -> m) -> Binding a -> m # foldr :: (a -> b -> b) -> b -> Binding a -> b # foldr' :: (a -> b -> b) -> b -> Binding a -> b # foldl :: (b -> a -> b) -> b -> Binding a -> b # foldl' :: (b -> a -> b) -> b -> Binding a -> b # foldr1 :: (a -> a -> a) -> Binding a -> a # foldl1 :: (a -> a -> a) -> Binding a -> a # elem :: Eq a => a -> Binding a -> Bool # maximum :: Ord a => Binding a -> a # minimum :: Ord a => Binding a -> a # | |
| Foldable NExprF Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => NExprF m -> m # foldMap :: Monoid m => (a -> m) -> NExprF a -> m # foldMap' :: Monoid m => (a -> m) -> NExprF a -> m # foldr :: (a -> b -> b) -> b -> NExprF a -> b # foldr' :: (a -> b -> b) -> b -> NExprF a -> b # foldl :: (b -> a -> b) -> b -> NExprF a -> b # foldl' :: (b -> a -> b) -> b -> NExprF a -> b # foldr1 :: (a -> a -> a) -> NExprF a -> a # foldl1 :: (a -> a -> a) -> NExprF a -> a # elem :: Eq a => a -> NExprF a -> Bool # maximum :: Ord a => NExprF a -> a # minimum :: Ord a => NExprF a -> a # | |
| Foldable NKeyName Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => NKeyName m -> m # foldMap :: Monoid m => (a -> m) -> NKeyName a -> m # foldMap' :: Monoid m => (a -> m) -> NKeyName a -> m # foldr :: (a -> b -> b) -> b -> NKeyName a -> b # foldr' :: (a -> b -> b) -> b -> NKeyName a -> b # foldl :: (b -> a -> b) -> b -> NKeyName a -> b # foldl' :: (b -> a -> b) -> b -> NKeyName a -> b # foldr1 :: (a -> a -> a) -> NKeyName a -> a # foldl1 :: (a -> a -> a) -> NKeyName a -> a # elem :: Eq a => a -> NKeyName a -> Bool # maximum :: Ord a => NKeyName a -> a # minimum :: Ord a => NKeyName a -> a # | |
| Foldable NString Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => NString m -> m # foldMap :: Monoid m => (a -> m) -> NString a -> m # foldMap' :: Monoid m => (a -> m) -> NString a -> m # foldr :: (a -> b -> b) -> b -> NString a -> b # foldr' :: (a -> b -> b) -> b -> NString a -> b # foldl :: (b -> a -> b) -> b -> NString a -> b # foldl' :: (b -> a -> b) -> b -> NString a -> b # foldr1 :: (a -> a -> a) -> NString a -> a # foldl1 :: (a -> a -> a) -> NString a -> a # elem :: Eq a => a -> NString a -> Bool # maximum :: Ord a => NString a -> a # minimum :: Ord a => NString a -> a # | |
| Foldable Params Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => Params m -> m # foldMap :: Monoid m => (a -> m) -> Params a -> m # foldMap' :: Monoid m => (a -> m) -> Params a -> m # foldr :: (a -> b -> b) -> b -> Params a -> b # foldr' :: (a -> b -> b) -> b -> Params a -> b # foldl :: (b -> a -> b) -> b -> Params a -> b # foldl' :: (b -> a -> b) -> b -> Params a -> b # foldr1 :: (a -> a -> a) -> Params a -> a # foldl1 :: (a -> a -> a) -> Params a -> a # elem :: Eq a => a -> Params a -> Bool # maximum :: Ord a => Params a -> a # minimum :: Ord a => Params a -> a # | |
| Foldable NSymbolicF Source # | |
Defined in Nix.Lint Methods fold :: Monoid m => NSymbolicF m -> m # foldMap :: Monoid m => (a -> m) -> NSymbolicF a -> m # foldMap' :: Monoid m => (a -> m) -> NSymbolicF a -> m # foldr :: (a -> b -> b) -> b -> NSymbolicF a -> b # foldr' :: (a -> b -> b) -> b -> NSymbolicF a -> b # foldl :: (b -> a -> b) -> b -> NSymbolicF a -> b # foldl' :: (b -> a -> b) -> b -> NSymbolicF a -> b # foldr1 :: (a -> a -> a) -> NSymbolicF a -> a # foldl1 :: (a -> a -> a) -> NSymbolicF a -> a # toList :: NSymbolicF a -> [a] # null :: NSymbolicF a -> Bool # length :: NSymbolicF a -> Int # elem :: Eq a => a -> NSymbolicF a -> Bool # maximum :: Ord a => NSymbolicF a -> a # minimum :: Ord a => NSymbolicF a -> a # sum :: Num a => NSymbolicF a -> a # product :: Num a => NSymbolicF a -> a # | |
| Foldable Scope Source # | |
Defined in Nix.Scope Methods fold :: Monoid m => Scope m -> m # foldMap :: Monoid m => (a -> m) -> Scope a -> m # foldMap' :: Monoid m => (a -> m) -> Scope a -> m # foldr :: (a -> b -> b) -> b -> Scope a -> b # foldr' :: (a -> b -> b) -> b -> Scope a -> b # foldl :: (b -> a -> b) -> b -> Scope a -> b # foldl' :: (b -> a -> b) -> b -> Scope a -> b # foldr1 :: (a -> a -> a) -> Scope a -> a # foldl1 :: (a -> a -> a) -> Scope a -> a # elem :: Eq a => a -> Scope a -> Bool # maximum :: Ord a => Scope a -> a # minimum :: Ord a => Scope a -> a # | |
| Foldable HistoriedResponse | |
Defined in Network.HTTP.Client Methods fold :: Monoid m => HistoriedResponse m -> m # foldMap :: Monoid m => (a -> m) -> HistoriedResponse a -> m # foldMap' :: Monoid m => (a -> m) -> HistoriedResponse a -> m # foldr :: (a -> b -> b) -> b -> HistoriedResponse a -> b # foldr' :: (a -> b -> b) -> b -> HistoriedResponse a -> b # foldl :: (b -> a -> b) -> b -> HistoriedResponse a -> b # foldl' :: (b -> a -> b) -> b -> HistoriedResponse a -> b # foldr1 :: (a -> a -> a) -> HistoriedResponse a -> a # foldl1 :: (a -> a -> a) -> HistoriedResponse a -> a # toList :: HistoriedResponse a -> [a] # null :: HistoriedResponse a -> Bool # length :: HistoriedResponse a -> Int # elem :: Eq a => a -> HistoriedResponse a -> Bool # maximum :: Ord a => HistoriedResponse a -> a # minimum :: Ord a => HistoriedResponse a -> a # sum :: Num a => HistoriedResponse a -> a # product :: Num a => HistoriedResponse a -> a # | |
| Foldable Response | |
Defined in Network.HTTP.Client.Types Methods fold :: Monoid m => Response m -> m # foldMap :: Monoid m => (a -> m) -> Response a -> m # foldMap' :: Monoid m => (a -> m) -> Response a -> m # foldr :: (a -> b -> b) -> b -> Response a -> b # foldr' :: (a -> b -> b) -> b -> Response a -> b # foldl :: (b -> a -> b) -> b -> Response a -> b # foldl' :: (b -> a -> b) -> b -> Response a -> b # foldr1 :: (a -> a -> a) -> Response a -> a # foldl1 :: (a -> a -> a) -> Response a -> a # elem :: Eq a => a -> Response a -> Bool # maximum :: Ord a => Response a -> a # minimum :: Ord a => Response a -> a # | |
| Foldable SimpleDocStream | Collect all annotations from a document. |
Defined in Prettyprinter.Internal Methods fold :: Monoid m => SimpleDocStream m -> m # foldMap :: Monoid m => (a -> m) -> SimpleDocStream a -> m # foldMap' :: Monoid m => (a -> m) -> SimpleDocStream a -> m # foldr :: (a -> b -> b) -> b -> SimpleDocStream a -> b # foldr' :: (a -> b -> b) -> b -> SimpleDocStream a -> b # foldl :: (b -> a -> b) -> b -> SimpleDocStream a -> b # foldl' :: (b -> a -> b) -> b -> SimpleDocStream a -> b # foldr1 :: (a -> a -> a) -> SimpleDocStream a -> a # foldl1 :: (a -> a -> a) -> SimpleDocStream a -> a # toList :: SimpleDocStream a -> [a] # null :: SimpleDocStream a -> Bool # length :: SimpleDocStream a -> Int # elem :: Eq a => a -> SimpleDocStream a -> Bool # maximum :: Ord a => SimpleDocStream a -> a # minimum :: Ord a => SimpleDocStream a -> a # sum :: Num a => SimpleDocStream a -> a # product :: Num a => SimpleDocStream a -> a # | |
| Foldable Array | |
Defined in Data.Primitive.Array Methods fold :: Monoid m => Array m -> m # foldMap :: Monoid m => (a -> m) -> Array a -> m # foldMap' :: Monoid m => (a -> m) -> Array a -> m # foldr :: (a -> b -> b) -> b -> Array a -> b # foldr' :: (a -> b -> b) -> b -> Array a -> b # foldl :: (b -> a -> b) -> b -> Array a -> b # foldl' :: (b -> a -> b) -> b -> Array a -> b # foldr1 :: (a -> a -> a) -> Array a -> a # foldl1 :: (a -> a -> a) -> Array a -> a # elem :: Eq a => a -> Array a -> Bool # maximum :: Ord a => Array a -> a # minimum :: Ord a => Array a -> a # | |
| Foldable SmallArray | |
Defined in Data.Primitive.SmallArray Methods fold :: Monoid m => SmallArray m -> m # foldMap :: Monoid m => (a -> m) -> SmallArray a -> m # foldMap' :: Monoid m => (a -> m) -> SmallArray a -> m # foldr :: (a -> b -> b) -> b -> SmallArray a -> b # foldr' :: (a -> b -> b) -> b -> SmallArray a -> b # foldl :: (b -> a -> b) -> b -> SmallArray a -> b # foldl' :: (b -> a -> b) -> b -> SmallArray a -> b # foldr1 :: (a -> a -> a) -> SmallArray a -> a # foldl1 :: (a -> a -> a) -> SmallArray a -> a # toList :: SmallArray a -> [a] # null :: SmallArray a -> Bool # length :: SmallArray a -> Int # elem :: Eq a => a -> SmallArray a -> Bool # maximum :: Ord a => SmallArray a -> a # minimum :: Ord a => SmallArray a -> a # sum :: Num a => SmallArray a -> a # product :: Num a => SmallArray a -> a # | |
| Foldable Maybe | |
Defined in Data.Strict.Maybe Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable HashSet | |
Defined in Data.HashSet.Internal Methods fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldMap' :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |
| Foldable Vector | |
Defined in Data.Vector Methods fold :: Monoid m => Vector m -> m # foldMap :: Monoid m => (a -> m) -> Vector a -> m # foldMap' :: Monoid m => (a -> m) -> Vector a -> m # foldr :: (a -> b -> b) -> b -> Vector a -> b # foldr' :: (a -> b -> b) -> b -> Vector a -> b # foldl :: (b -> a -> b) -> b -> Vector a -> b # foldl' :: (b -> a -> b) -> b -> Vector a -> b # foldr1 :: (a -> a -> a) -> Vector a -> a # foldl1 :: (a -> a -> a) -> Vector a -> a # elem :: Eq a => a -> Vector a -> Bool # maximum :: Ord a => Vector a -> a # minimum :: Ord a => Vector a -> a # | |
| Foldable NonEmpty | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # | |
| Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Foldable Solo | Since: base-4.15 |
Defined in Data.Foldable Methods fold :: Monoid m => Solo m -> m # foldMap :: Monoid m => (a -> m) -> Solo a -> m # foldMap' :: Monoid m => (a -> m) -> Solo a -> m # foldr :: (a -> b -> b) -> b -> Solo a -> b # foldr' :: (a -> b -> b) -> b -> Solo a -> b # foldl :: (b -> a -> b) -> b -> Solo a -> b # foldl' :: (b -> a -> b) -> b -> Solo a -> b # foldr1 :: (a -> a -> a) -> Solo a -> a # foldl1 :: (a -> a -> a) -> Solo a -> a # elem :: Eq a => a -> Solo a -> Bool # maximum :: Ord a => Solo a -> a # | |
| Foldable [] | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => [m] -> m # foldMap :: Monoid m => (a -> m) -> [a] -> m # foldMap' :: Monoid m => (a -> m) -> [a] -> m # foldr :: (a -> b -> b) -> b -> [a] -> b # foldr' :: (a -> b -> b) -> b -> [a] -> b # foldl :: (b -> a -> b) -> b -> [a] -> b # foldl' :: (b -> a -> b) -> b -> [a] -> b # foldr1 :: (a -> a -> a) -> [a] -> a # foldl1 :: (a -> a -> a) -> [a] -> a # elem :: Eq a => a -> [a] -> Bool # maximum :: Ord a => [a] -> a # | |
| Foldable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # | |
| Foldable (Proxy :: TYPE LiftedRep -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Foldable (Arg a) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods fold :: Monoid m => Arg a m -> m # foldMap :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Arg a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Arg a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Arg a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Arg a a0 -> a0 # elem :: Eq a0 => a0 -> Arg a a0 -> Bool # maximum :: Ord a0 => Arg a a0 -> a0 # minimum :: Ord a0 => Arg a a0 -> a0 # | |
| Foldable (Array i) | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Array i m -> m # foldMap :: Monoid m => (a -> m) -> Array i a -> m # foldMap' :: Monoid m => (a -> m) -> Array i a -> m # foldr :: (a -> b -> b) -> b -> Array i a -> b # foldr' :: (a -> b -> b) -> b -> Array i a -> b # foldl :: (b -> a -> b) -> b -> Array i a -> b # foldl' :: (b -> a -> b) -> b -> Array i a -> b # foldr1 :: (a -> a -> a) -> Array i a -> a # foldl1 :: (a -> a -> a) -> Array i a -> a # elem :: Eq a => a -> Array i a -> Bool # maximum :: Ord a => Array i a -> a # minimum :: Ord a => Array i a -> a # | |
| Foldable (U1 :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => U1 m -> m # foldMap :: Monoid m => (a -> m) -> U1 a -> m # foldMap' :: Monoid m => (a -> m) -> U1 a -> m # foldr :: (a -> b -> b) -> b -> U1 a -> b # foldr' :: (a -> b -> b) -> b -> U1 a -> b # foldl :: (b -> a -> b) -> b -> U1 a -> b # foldl' :: (b -> a -> b) -> b -> U1 a -> b # foldr1 :: (a -> a -> a) -> U1 a -> a # foldl1 :: (a -> a -> a) -> U1 a -> a # elem :: Eq a => a -> U1 a -> Bool # maximum :: Ord a => U1 a -> a # | |
| Foldable (UAddr :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UAddr m -> m # foldMap :: Monoid m => (a -> m) -> UAddr a -> m # foldMap' :: Monoid m => (a -> m) -> UAddr a -> m # foldr :: (a -> b -> b) -> b -> UAddr a -> b # foldr' :: (a -> b -> b) -> b -> UAddr a -> b # foldl :: (b -> a -> b) -> b -> UAddr a -> b # foldl' :: (b -> a -> b) -> b -> UAddr a -> b # foldr1 :: (a -> a -> a) -> UAddr a -> a # foldl1 :: (a -> a -> a) -> UAddr a -> a # elem :: Eq a => a -> UAddr a -> Bool # maximum :: Ord a => UAddr a -> a # minimum :: Ord a => UAddr a -> a # | |
| Foldable (UChar :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UChar m -> m # foldMap :: Monoid m => (a -> m) -> UChar a -> m # foldMap' :: Monoid m => (a -> m) -> UChar a -> m # foldr :: (a -> b -> b) -> b -> UChar a -> b # foldr' :: (a -> b -> b) -> b -> UChar a -> b # foldl :: (b -> a -> b) -> b -> UChar a -> b # foldl' :: (b -> a -> b) -> b -> UChar a -> b # foldr1 :: (a -> a -> a) -> UChar a -> a # foldl1 :: (a -> a -> a) -> UChar a -> a # elem :: Eq a => a -> UChar a -> Bool # maximum :: Ord a => UChar a -> a # minimum :: Ord a => UChar a -> a # | |
| Foldable (UDouble :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UDouble m -> m # foldMap :: Monoid m => (a -> m) -> UDouble a -> m # foldMap' :: Monoid m => (a -> m) -> UDouble a -> m # foldr :: (a -> b -> b) -> b -> UDouble a -> b # foldr' :: (a -> b -> b) -> b -> UDouble a -> b # foldl :: (b -> a -> b) -> b -> UDouble a -> b # foldl' :: (b -> a -> b) -> b -> UDouble a -> b # foldr1 :: (a -> a -> a) -> UDouble a -> a # foldl1 :: (a -> a -> a) -> UDouble a -> a # elem :: Eq a => a -> UDouble a -> Bool # maximum :: Ord a => UDouble a -> a # minimum :: Ord a => UDouble a -> a # | |
| Foldable (UFloat :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
| Foldable (UInt :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UInt m -> m # foldMap :: Monoid m => (a -> m) -> UInt a -> m # foldMap' :: Monoid m => (a -> m) -> UInt a -> m # foldr :: (a -> b -> b) -> b -> UInt a -> b # foldr' :: (a -> b -> b) -> b -> UInt a -> b # foldl :: (b -> a -> b) -> b -> UInt a -> b # foldl' :: (b -> a -> b) -> b -> UInt a -> b # foldr1 :: (a -> a -> a) -> UInt a -> a # foldl1 :: (a -> a -> a) -> UInt a -> a # elem :: Eq a => a -> UInt a -> Bool # maximum :: Ord a => UInt a -> a # | |
| Foldable (UWord :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UWord m -> m # foldMap :: Monoid m => (a -> m) -> UWord a -> m # foldMap' :: Monoid m => (a -> m) -> UWord a -> m # foldr :: (a -> b -> b) -> b -> UWord a -> b # foldr' :: (a -> b -> b) -> b -> UWord a -> b # foldl :: (b -> a -> b) -> b -> UWord a -> b # foldl' :: (b -> a -> b) -> b -> UWord a -> b # foldr1 :: (a -> a -> a) -> UWord a -> a # foldl1 :: (a -> a -> a) -> UWord a -> a # elem :: Eq a => a -> UWord a -> Bool # maximum :: Ord a => UWord a -> a # minimum :: Ord a => UWord a -> a # | |
| Foldable (V1 :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => V1 m -> m # foldMap :: Monoid m => (a -> m) -> V1 a -> m # foldMap' :: Monoid m => (a -> m) -> V1 a -> m # foldr :: (a -> b -> b) -> b -> V1 a -> b # foldr' :: (a -> b -> b) -> b -> V1 a -> b # foldl :: (b -> a -> b) -> b -> V1 a -> b # foldl' :: (b -> a -> b) -> b -> V1 a -> b # foldr1 :: (a -> a -> a) -> V1 a -> a # foldl1 :: (a -> a -> a) -> V1 a -> a # elem :: Eq a => a -> V1 a -> Bool # maximum :: Ord a => V1 a -> a # | |
| Foldable (Map k) | Folds in order of increasing key. |
Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # | |
| Foldable f => Foldable (Free f) | |
Defined in Control.Monad.Free Methods fold :: Monoid m => Free f m -> m # foldMap :: Monoid m => (a -> m) -> Free f a -> m # foldMap' :: Monoid m => (a -> m) -> Free f a -> m # foldr :: (a -> b -> b) -> b -> Free f a -> b # foldr' :: (a -> b -> b) -> b -> Free f a -> b # foldl :: (b -> a -> b) -> b -> Free f a -> b # foldl' :: (b -> a -> b) -> b -> Free f a -> b # foldr1 :: (a -> a -> a) -> Free f a -> a # foldl1 :: (a -> a -> a) -> Free f a -> a # elem :: Eq a => a -> Free f a -> Bool # maximum :: Ord a => Free f a -> a # minimum :: Ord a => Free f a -> a # | |
| Foldable (Antiquoted v) Source # | |
Defined in Nix.Expr.Types Methods fold :: Monoid m => Antiquoted v m -> m # foldMap :: Monoid m => (a -> m) -> Antiquoted v a -> m # foldMap' :: Monoid m => (a -> m) -> Antiquoted v a -> m # foldr :: (a -> b -> b) -> b -> Antiquoted v a -> b # foldr' :: (a -> b -> b) -> b -> Antiquoted v a -> b # foldl :: (b -> a -> b) -> b -> Antiquoted v a -> b # foldl' :: (b -> a -> b) -> b -> Antiquoted v a -> b # foldr1 :: (a -> a -> a) -> Antiquoted v a -> a # foldl1 :: (a -> a -> a) -> Antiquoted v a -> a # toList :: Antiquoted v a -> [a] # null :: Antiquoted v a -> Bool # length :: Antiquoted v a -> Int # elem :: Eq a => a -> Antiquoted v a -> Bool # maximum :: Ord a => Antiquoted v a -> a # minimum :: Ord a => Antiquoted v a -> a # sum :: Num a => Antiquoted v a -> a # product :: Num a => Antiquoted v a -> a # | |
| Foldable (AnnUnit ann) Source # | |
Defined in Nix.Expr.Types.Annotated Methods fold :: Monoid m => AnnUnit ann m -> m # foldMap :: Monoid m => (a -> m) -> AnnUnit ann a -> m # foldMap' :: Monoid m => (a -> m) -> AnnUnit ann a -> m # foldr :: (a -> b -> b) -> b -> AnnUnit ann a -> b # foldr' :: (a -> b -> b) -> b -> AnnUnit ann a -> b # foldl :: (b -> a -> b) -> b -> AnnUnit ann a -> b # foldl' :: (b -> a -> b) -> b -> AnnUnit ann a -> b # foldr1 :: (a -> a -> a) -> AnnUnit ann a -> a # foldl1 :: (a -> a -> a) -> AnnUnit ann a -> a # toList :: AnnUnit ann a -> [a] # null :: AnnUnit ann a -> Bool # length :: AnnUnit ann a -> Int # elem :: Eq a => a -> AnnUnit ann a -> Bool # maximum :: Ord a => AnnUnit ann a -> a # minimum :: Ord a => AnnUnit ann a -> a # | |
| Foldable (StdCited m) Source # | |
Defined in Nix.Standard Methods fold :: Monoid m0 => StdCited m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> StdCited m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> StdCited m a -> m0 # foldr :: (a -> b -> b) -> b -> StdCited m a -> b # foldr' :: (a -> b -> b) -> b -> StdCited m a -> b # foldl :: (b -> a -> b) -> b -> StdCited m a -> b # foldl' :: (b -> a -> b) -> b -> StdCited m a -> b # foldr1 :: (a -> a -> a) -> StdCited m a -> a # foldl1 :: (a -> a -> a) -> StdCited m a -> a # toList :: StdCited m a -> [a] # null :: StdCited m a -> Bool # length :: StdCited m a -> Int # elem :: Eq a => a -> StdCited m a -> Bool # maximum :: Ord a => StdCited m a -> a # minimum :: Ord a => StdCited m a -> a # | |
| Foldable m => Foldable (Deferred m) Source # | |
Defined in Nix.Thunk.Basic Methods fold :: Monoid m0 => Deferred m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Deferred m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Deferred m a -> m0 # foldr :: (a -> b -> b) -> b -> Deferred m a -> b # foldr' :: (a -> b -> b) -> b -> Deferred m a -> b # foldl :: (b -> a -> b) -> b -> Deferred m a -> b # foldl' :: (b -> a -> b) -> b -> Deferred m a -> b # foldr1 :: (a -> a -> a) -> Deferred m a -> a # foldl1 :: (a -> a -> a) -> Deferred m a -> a # toList :: Deferred m a -> [a] # null :: Deferred m a -> Bool # length :: Deferred m a -> Int # elem :: Eq a => a -> Deferred m a -> Bool # maximum :: Ord a => Deferred m a -> a # minimum :: Ord a => Deferred m a -> a # | |
| Foldable (LogicT Identity) | Since: logict-0.5.0 |
Defined in Control.Monad.Logic Methods fold :: Monoid m => LogicT Identity m -> m # foldMap :: Monoid m => (a -> m) -> LogicT Identity a -> m # foldMap' :: Monoid m => (a -> m) -> LogicT Identity a -> m # foldr :: (a -> b -> b) -> b -> LogicT Identity a -> b # foldr' :: (a -> b -> b) -> b -> LogicT Identity a -> b # foldl :: (b -> a -> b) -> b -> LogicT Identity a -> b # foldl' :: (b -> a -> b) -> b -> LogicT Identity a -> b # foldr1 :: (a -> a -> a) -> LogicT Identity a -> a # foldl1 :: (a -> a -> a) -> LogicT Identity a -> a # toList :: LogicT Identity a -> [a] # null :: LogicT Identity a -> Bool # length :: LogicT Identity a -> Int # elem :: Eq a => a -> LogicT Identity a -> Bool # maximum :: Ord a => LogicT Identity a -> a # minimum :: Ord a => LogicT Identity a -> a # | |
| (Applicative m, Foldable m) => Foldable (LogicT m) | Since: logict-0.5.0 |
Defined in Control.Monad.Logic Methods fold :: Monoid m0 => LogicT m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> LogicT m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> LogicT m a -> m0 # foldr :: (a -> b -> b) -> b -> LogicT m a -> b # foldr' :: (a -> b -> b) -> b -> LogicT m a -> b # foldl :: (b -> a -> b) -> b -> LogicT m a -> b # foldl' :: (b -> a -> b) -> b -> LogicT m a -> b # foldr1 :: (a -> a -> a) -> LogicT m a -> a # foldl1 :: (a -> a -> a) -> LogicT m a -> a # elem :: Eq a => a -> LogicT m a -> Bool # maximum :: Ord a => LogicT m a -> a # minimum :: Ord a => LogicT m a -> a # | |
| Foldable m => Foldable (ML m) | |
Defined in Control.Monad.Logic Methods fold :: Monoid m0 => ML m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> ML m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> ML m a -> m0 # foldr :: (a -> b -> b) -> b -> ML m a -> b # foldr' :: (a -> b -> b) -> b -> ML m a -> b # foldl :: (b -> a -> b) -> b -> ML m a -> b # foldl' :: (b -> a -> b) -> b -> ML m a -> b # foldr1 :: (a -> a -> a) -> ML m a -> a # foldl1 :: (a -> a -> a) -> ML m a -> a # elem :: Eq a => a -> ML m a -> Bool # maximum :: Ord a => ML m a -> a # | |
| Foldable m => Foldable (MLView m) | |
Defined in Control.Monad.Logic Methods fold :: Monoid m0 => MLView m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> MLView m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> MLView m a -> m0 # foldr :: (a -> b -> b) -> b -> MLView m a -> b # foldr' :: (a -> b -> b) -> b -> MLView m a -> b # foldl :: (b -> a -> b) -> b -> MLView m a -> b # foldl' :: (b -> a -> b) -> b -> MLView m a -> b # foldr1 :: (a -> a -> a) -> MLView m a -> a # foldl1 :: (a -> a -> a) -> MLView m a -> a # elem :: Eq a => a -> MLView m a -> Bool # maximum :: Ord a => MLView m a -> a # minimum :: Ord a => MLView m a -> a # | |
| Foldable (Either e) | |
Defined in Data.Strict.Either Methods fold :: Monoid m => Either e m -> m # foldMap :: Monoid m => (a -> m) -> Either e a -> m # foldMap' :: Monoid m => (a -> m) -> Either e a -> m # foldr :: (a -> b -> b) -> b -> Either e a -> b # foldr' :: (a -> b -> b) -> b -> Either e a -> b # foldl :: (b -> a -> b) -> b -> Either e a -> b # foldl' :: (b -> a -> b) -> b -> Either e a -> b # foldr1 :: (a -> a -> a) -> Either e a -> a # foldl1 :: (a -> a -> a) -> Either e a -> a # elem :: Eq a => a -> Either e a -> Bool # maximum :: Ord a => Either e a -> a # minimum :: Ord a => Either e a -> a # | |
| Foldable (These a) | |
Defined in Data.Strict.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable (Pair e) | |
Defined in Data.Strict.Tuple Methods fold :: Monoid m => Pair e m -> m # foldMap :: Monoid m => (a -> m) -> Pair e a -> m # foldMap' :: Monoid m => (a -> m) -> Pair e a -> m # foldr :: (a -> b -> b) -> b -> Pair e a -> b # foldr' :: (a -> b -> b) -> b -> Pair e a -> b # foldl :: (b -> a -> b) -> b -> Pair e a -> b # foldl' :: (b -> a -> b) -> b -> Pair e a -> b # foldr1 :: (a -> a -> a) -> Pair e a -> a # foldl1 :: (a -> a -> a) -> Pair e a -> a # elem :: Eq a => a -> Pair e a -> Bool # maximum :: Ord a => Pair e a -> a # minimum :: Ord a => Pair e a -> a # | |
| Foldable (These a) | |
Defined in Data.These Methods fold :: Monoid m => These a m -> m # foldMap :: Monoid m => (a0 -> m) -> These a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> These a a0 -> m # foldr :: (a0 -> b -> b) -> b -> These a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> These a a0 -> b # foldl :: (b -> a0 -> b) -> b -> These a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> These a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> These a a0 -> a0 # toList :: These a a0 -> [a0] # elem :: Eq a0 => a0 -> These a a0 -> Bool # maximum :: Ord a0 => These a a0 -> a0 # minimum :: Ord a0 => These a a0 -> a0 # | |
| Foldable f => Foldable (ListT f) | |
Defined in Control.Monad.Trans.List Methods fold :: Monoid m => ListT f m -> m # foldMap :: Monoid m => (a -> m) -> ListT f a -> m # foldMap' :: Monoid m => (a -> m) -> ListT f a -> m # foldr :: (a -> b -> b) -> b -> ListT f a -> b # foldr' :: (a -> b -> b) -> b -> ListT f a -> b # foldl :: (b -> a -> b) -> b -> ListT f a -> b # foldl' :: (b -> a -> b) -> b -> ListT f a -> b # foldr1 :: (a -> a -> a) -> ListT f a -> a # foldl1 :: (a -> a -> a) -> ListT f a -> a # elem :: Eq a => a -> ListT f a -> Bool # maximum :: Ord a => ListT f a -> a # minimum :: Ord a => ListT f a -> a # | |
| Foldable f => Foldable (MaybeT f) | |
Defined in Control.Monad.Trans.Maybe Methods fold :: Monoid m => MaybeT f m -> m # foldMap :: Monoid m => (a -> m) -> MaybeT f a -> m # foldMap' :: Monoid m => (a -> m) -> MaybeT f a -> m # foldr :: (a -> b -> b) -> b -> MaybeT f a -> b # foldr' :: (a -> b -> b) -> b -> MaybeT f a -> b # foldl :: (b -> a -> b) -> b -> MaybeT f a -> b # foldl' :: (b -> a -> b) -> b -> MaybeT f a -> b # foldr1 :: (a -> a -> a) -> MaybeT f a -> a # foldl1 :: (a -> a -> a) -> MaybeT f a -> a # elem :: Eq a => a -> MaybeT f a -> Bool # maximum :: Ord a => MaybeT f a -> a # minimum :: Ord a => MaybeT f a -> a # | |
| Foldable (HashMap k) | |
Defined in Data.HashMap.Internal Methods fold :: Monoid m => HashMap k m -> m # foldMap :: Monoid m => (a -> m) -> HashMap k a -> m # foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m # foldr :: (a -> b -> b) -> b -> HashMap k a -> b # foldr' :: (a -> b -> b) -> b -> HashMap k a -> b # foldl :: (b -> a -> b) -> b -> HashMap k a -> b # foldl' :: (b -> a -> b) -> b -> HashMap k a -> b # foldr1 :: (a -> a -> a) -> HashMap k a -> a # foldl1 :: (a -> a -> a) -> HashMap k a -> a # toList :: HashMap k a -> [a] # length :: HashMap k a -> Int # elem :: Eq a => a -> HashMap k a -> Bool # maximum :: Ord a => HashMap k a -> a # minimum :: Ord a => HashMap k a -> a # | |
| Foldable ((,) a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (a, m) -> m # foldMap :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldMap' :: Monoid m => (a0 -> m) -> (a, a0) -> m # foldr :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldr' :: (a0 -> b -> b) -> b -> (a, a0) -> b # foldl :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldl' :: (b -> a0 -> b) -> b -> (a, a0) -> b # foldr1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # foldl1 :: (a0 -> a0 -> a0) -> (a, a0) -> a0 # elem :: Eq a0 => a0 -> (a, a0) -> Bool # maximum :: Ord a0 => (a, a0) -> a0 # minimum :: Ord a0 => (a, a0) -> a0 # | |
| Foldable (Const m :: TYPE LiftedRep -> Type) | Since: base-4.7.0.0 |
Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # | |
| Foldable f => Foldable (Ap f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m # foldMap :: Monoid m => (a -> m) -> Ap f a -> m # foldMap' :: Monoid m => (a -> m) -> Ap f a -> m # foldr :: (a -> b -> b) -> b -> Ap f a -> b # foldr' :: (a -> b -> b) -> b -> Ap f a -> b # foldl :: (b -> a -> b) -> b -> Ap f a -> b # foldl' :: (b -> a -> b) -> b -> Ap f a -> b # foldr1 :: (a -> a -> a) -> Ap f a -> a # foldl1 :: (a -> a -> a) -> Ap f a -> a # elem :: Eq a => a -> Ap f a -> Bool # maximum :: Ord a => Ap f a -> a # | |
| Foldable f => Foldable (Alt f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # | |
| Foldable f => Foldable (Rec1 f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Rec1 f m -> m # foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m # foldMap' :: Monoid m => (a -> m) -> Rec1 f a -> m # foldr :: (a -> b -> b) -> b -> Rec1 f a -> b # foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b # foldl :: (b -> a -> b) -> b -> Rec1 f a -> b # foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b # foldr1 :: (a -> a -> a) -> Rec1 f a -> a # foldl1 :: (a -> a -> a) -> Rec1 f a -> a # elem :: Eq a => a -> Rec1 f a -> Bool # maximum :: Ord a => Rec1 f a -> a # minimum :: Ord a => Rec1 f a -> a # | |
| Bifoldable p => Foldable (Join p) | |
Defined in Data.Bifunctor.Join Methods fold :: Monoid m => Join p m -> m # foldMap :: Monoid m => (a -> m) -> Join p a -> m # foldMap' :: Monoid m => (a -> m) -> Join p a -> m # foldr :: (a -> b -> b) -> b -> Join p a -> b # foldr' :: (a -> b -> b) -> b -> Join p a -> b # foldl :: (b -> a -> b) -> b -> Join p a -> b # foldl' :: (b -> a -> b) -> b -> Join p a -> b # foldr1 :: (a -> a -> a) -> Join p a -> a # foldl1 :: (a -> a -> a) -> Join p a -> a # elem :: Eq a => a -> Join p a -> Bool # maximum :: Ord a => Join p a -> a # minimum :: Ord a => Join p a -> a # | |
| Foldable w => Foldable (EnvT e w) | |
Defined in Control.Comonad.Trans.Env Methods fold :: Monoid m => EnvT e w m -> m # foldMap :: Monoid m => (a -> m) -> EnvT e w a -> m # foldMap' :: Monoid m => (a -> m) -> EnvT e w a -> m # foldr :: (a -> b -> b) -> b -> EnvT e w a -> b # foldr' :: (a -> b -> b) -> b -> EnvT e w a -> b # foldl :: (b -> a -> b) -> b -> EnvT e w a -> b # foldl' :: (b -> a -> b) -> b -> EnvT e w a -> b # foldr1 :: (a -> a -> a) -> EnvT e w a -> a # foldl1 :: (a -> a -> a) -> EnvT e w a -> a # elem :: Eq a => a -> EnvT e w a -> Bool # maximum :: Ord a => EnvT e w a -> a # minimum :: Ord a => EnvT e w a -> a # | |
| Foldable f => Foldable (FreeF f a) | |
Defined in Control.Monad.Trans.Free Methods fold :: Monoid m => FreeF f a m -> m # foldMap :: Monoid m => (a0 -> m) -> FreeF f a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> FreeF f a a0 -> m # foldr :: (a0 -> b -> b) -> b -> FreeF f a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> FreeF f a a0 -> b # foldl :: (b -> a0 -> b) -> b -> FreeF f a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> FreeF f a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> FreeF f a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> FreeF f a a0 -> a0 # toList :: FreeF f a a0 -> [a0] # null :: FreeF f a a0 -> Bool # length :: FreeF f a a0 -> Int # elem :: Eq a0 => a0 -> FreeF f a a0 -> Bool # maximum :: Ord a0 => FreeF f a a0 -> a0 # minimum :: Ord a0 => FreeF f a a0 -> a0 # | |
| (Foldable m, Foldable f) => Foldable (FreeT f m) | |
Defined in Control.Monad.Trans.Free Methods fold :: Monoid m0 => FreeT f m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> FreeT f m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> FreeT f m a -> m0 # foldr :: (a -> b -> b) -> b -> FreeT f m a -> b # foldr' :: (a -> b -> b) -> b -> FreeT f m a -> b # foldl :: (b -> a -> b) -> b -> FreeT f m a -> b # foldl' :: (b -> a -> b) -> b -> FreeT f m a -> b # foldr1 :: (a -> a -> a) -> FreeT f m a -> a # foldl1 :: (a -> a -> a) -> FreeT f m a -> a # toList :: FreeT f m a -> [a] # length :: FreeT f m a -> Int # elem :: Eq a => a -> FreeT f m a -> Bool # maximum :: Ord a => FreeT f m a -> a # minimum :: Ord a => FreeT f m a -> a # | |
| Foldable (NCited m v) Source # | |
Defined in Nix.Cited Methods fold :: Monoid m0 => NCited m v m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> NCited m v a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> NCited m v a -> m0 # foldr :: (a -> b -> b) -> b -> NCited m v a -> b # foldr' :: (a -> b -> b) -> b -> NCited m v a -> b # foldl :: (b -> a -> b) -> b -> NCited m v a -> b # foldl' :: (b -> a -> b) -> b -> NCited m v a -> b # foldr1 :: (a -> a -> a) -> NCited m v a -> a # foldl1 :: (a -> a -> a) -> NCited m v a -> a # toList :: NCited m v a -> [a] # null :: NCited m v a -> Bool # length :: NCited m v a -> Int # elem :: Eq a => a -> NCited m v a -> Bool # maximum :: Ord a => NCited m v a -> a # minimum :: Ord a => NCited m v a -> a # | |
| Foldable (NValueF p m) Source # | Folds what the value is known to contain at time of fold. |
Defined in Nix.Value Methods fold :: Monoid m0 => NValueF p m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> NValueF p m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> NValueF p m a -> m0 # foldr :: (a -> b -> b) -> b -> NValueF p m a -> b # foldr' :: (a -> b -> b) -> b -> NValueF p m a -> b # foldl :: (b -> a -> b) -> b -> NValueF p m a -> b # foldl' :: (b -> a -> b) -> b -> NValueF p m a -> b # foldr1 :: (a -> a -> a) -> NValueF p m a -> a # foldl1 :: (a -> a -> a) -> NValueF p m a -> a # toList :: NValueF p m a -> [a] # null :: NValueF p m a -> Bool # length :: NValueF p m a -> Int # elem :: Eq a => a -> NValueF p m a -> Bool # maximum :: Ord a => NValueF p m a -> a # minimum :: Ord a => NValueF p m a -> a # | |
| Foldable (Tagged s) | |
Defined in Data.Tagged Methods fold :: Monoid m => Tagged s m -> m # foldMap :: Monoid m => (a -> m) -> Tagged s a -> m # foldMap' :: Monoid m => (a -> m) -> Tagged s a -> m # foldr :: (a -> b -> b) -> b -> Tagged s a -> b # foldr' :: (a -> b -> b) -> b -> Tagged s a -> b # foldl :: (b -> a -> b) -> b -> Tagged s a -> b # foldl' :: (b -> a -> b) -> b -> Tagged s a -> b # foldr1 :: (a -> a -> a) -> Tagged s a -> a # foldl1 :: (a -> a -> a) -> Tagged s a -> a # elem :: Eq a => a -> Tagged s a -> Bool # maximum :: Ord a => Tagged s a -> a # minimum :: Ord a => Tagged s a -> a # | |
| (Foldable f, Foldable g) => Foldable (These1 f g) | |
Defined in Data.Functor.These Methods fold :: Monoid m => These1 f g m -> m # foldMap :: Monoid m => (a -> m) -> These1 f g a -> m # foldMap' :: Monoid m => (a -> m) -> These1 f g a -> m # foldr :: (a -> b -> b) -> b -> These1 f g a -> b # foldr' :: (a -> b -> b) -> b -> These1 f g a -> b # foldl :: (b -> a -> b) -> b -> These1 f g a -> b # foldl' :: (b -> a -> b) -> b -> These1 f g a -> b # foldr1 :: (a -> a -> a) -> These1 f g a -> a # foldl1 :: (a -> a -> a) -> These1 f g a -> a # toList :: These1 f g a -> [a] # null :: These1 f g a -> Bool # length :: These1 f g a -> Int # elem :: Eq a => a -> These1 f g a -> Bool # maximum :: Ord a => These1 f g a -> a # minimum :: Ord a => These1 f g a -> a # | |
| Foldable f => Foldable (ErrorT e f) | |
Defined in Control.Monad.Trans.Error Methods fold :: Monoid m => ErrorT e f m -> m # foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ErrorT e f a -> m # foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b # foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b # foldr1 :: (a -> a -> a) -> ErrorT e f a -> a # foldl1 :: (a -> a -> a) -> ErrorT e f a -> a # toList :: ErrorT e f a -> [a] # null :: ErrorT e f a -> Bool # length :: ErrorT e f a -> Int # elem :: Eq a => a -> ErrorT e f a -> Bool # maximum :: Ord a => ErrorT e f a -> a # minimum :: Ord a => ErrorT e f a -> a # | |
| Foldable f => Foldable (ExceptT e f) | |
Defined in Control.Monad.Trans.Except Methods fold :: Monoid m => ExceptT e f m -> m # foldMap :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldMap' :: Monoid m => (a -> m) -> ExceptT e f a -> m # foldr :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldr' :: (a -> b -> b) -> b -> ExceptT e f a -> b # foldl :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldl' :: (b -> a -> b) -> b -> ExceptT e f a -> b # foldr1 :: (a -> a -> a) -> ExceptT e f a -> a # foldl1 :: (a -> a -> a) -> ExceptT e f a -> a # toList :: ExceptT e f a -> [a] # null :: ExceptT e f a -> Bool # length :: ExceptT e f a -> Int # elem :: Eq a => a -> ExceptT e f a -> Bool # maximum :: Ord a => ExceptT e f a -> a # minimum :: Ord a => ExceptT e f a -> a # | |
| Foldable f => Foldable (IdentityT f) | |
Defined in Control.Monad.Trans.Identity Methods fold :: Monoid m => IdentityT f m -> m # foldMap :: Monoid m => (a -> m) -> IdentityT f a -> m # foldMap' :: Monoid m => (a -> m) -> IdentityT f a -> m # foldr :: (a -> b -> b) -> b -> IdentityT f a -> b # foldr' :: (a -> b -> b) -> b -> IdentityT f a -> b # foldl :: (b -> a -> b) -> b -> IdentityT f a -> b # foldl' :: (b -> a -> b) -> b -> IdentityT f a -> b # foldr1 :: (a -> a -> a) -> IdentityT f a -> a # foldl1 :: (a -> a -> a) -> IdentityT f a -> a # toList :: IdentityT f a -> [a] # null :: IdentityT f a -> Bool # length :: IdentityT f a -> Int # elem :: Eq a => a -> IdentityT f a -> Bool # maximum :: Ord a => IdentityT f a -> a # minimum :: Ord a => IdentityT f a -> a # | |
| Foldable f => Foldable (WriterT w f) | |
Defined in Control.Monad.Trans.Writer.Lazy Methods fold :: Monoid m => WriterT w f m -> m # foldMap :: Monoid m => (a -> m) -> WriterT w f a -> m # foldMap' :: Monoid m => (a -> m) -> WriterT w f a -> m # foldr :: (a -> b -> b) -> b -> WriterT w f a -> b # foldr' :: (a -> b -> b) -> b -> WriterT w f a -> b # foldl :: (b -> a -> b) -> b -> WriterT w f a -> b # foldl' :: (b -> a -> b) -> b -> WriterT w f a -> b # foldr1 :: (a -> a -> a) -> WriterT w f a -> a # foldl1 :: (a -> a -> a) -> WriterT w f a -> a # toList :: WriterT w f a -> [a] # null :: WriterT w f a -> Bool # length :: WriterT w f a -> Int # elem :: Eq a => a -> WriterT w f a -> Bool # maximum :: Ord a => WriterT w f a -> a # minimum :: Ord a => WriterT w f a -> a # | |
| Foldable f => Foldable (WriterT w f) | |
Defined in Control.Monad.Trans.Writer.Strict Methods fold :: Monoid m => WriterT w f m -> m # foldMap :: Monoid m => (a -> m) -> WriterT w f a -> m # foldMap' :: Monoid m => (a -> m) -> WriterT w f a -> m # foldr :: (a -> b -> b) -> b -> WriterT w f a -> b # foldr' :: (a -> b -> b) -> b -> WriterT w f a -> b # foldl :: (b -> a -> b) -> b -> WriterT w f a -> b # foldl' :: (b -> a -> b) -> b -> WriterT w f a -> b # foldr1 :: (a -> a -> a) -> WriterT w f a -> a # foldl1 :: (a -> a -> a) -> WriterT w f a -> a # toList :: WriterT w f a -> [a] # null :: WriterT w f a -> Bool # length :: WriterT w f a -> Int # elem :: Eq a => a -> WriterT w f a -> Bool # maximum :: Ord a => WriterT w f a -> a # minimum :: Ord a => WriterT w f a -> a # | |
| Foldable (Constant a :: TYPE LiftedRep -> Type) | |
Defined in Data.Functor.Constant Methods fold :: Monoid m => Constant a m -> m # foldMap :: Monoid m => (a0 -> m) -> Constant a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Constant a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Constant a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Constant a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Constant a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Constant a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Constant a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Constant a a0 -> a0 # toList :: Constant a a0 -> [a0] # null :: Constant a a0 -> Bool # length :: Constant a a0 -> Int # elem :: Eq a0 => a0 -> Constant a a0 -> Bool # maximum :: Ord a0 => Constant a a0 -> a0 # minimum :: Ord a0 => Constant a a0 -> a0 # | |
| (Foldable f, Foldable g) => Foldable (Product f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Product Methods fold :: Monoid m => Product f g m -> m # foldMap :: Monoid m => (a -> m) -> Product f g a -> m # foldMap' :: Monoid m => (a -> m) -> Product f g a -> m # foldr :: (a -> b -> b) -> b -> Product f g a -> b # foldr' :: (a -> b -> b) -> b -> Product f g a -> b # foldl :: (b -> a -> b) -> b -> Product f g a -> b # foldl' :: (b -> a -> b) -> b -> Product f g a -> b # foldr1 :: (a -> a -> a) -> Product f g a -> a # foldl1 :: (a -> a -> a) -> Product f g a -> a # toList :: Product f g a -> [a] # null :: Product f g a -> Bool # length :: Product f g a -> Int # elem :: Eq a => a -> Product f g a -> Bool # maximum :: Ord a => Product f g a -> a # minimum :: Ord a => Product f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (Sum f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Sum Methods fold :: Monoid m => Sum f g m -> m # foldMap :: Monoid m => (a -> m) -> Sum f g a -> m # foldMap' :: Monoid m => (a -> m) -> Sum f g a -> m # foldr :: (a -> b -> b) -> b -> Sum f g a -> b # foldr' :: (a -> b -> b) -> b -> Sum f g a -> b # foldl :: (b -> a -> b) -> b -> Sum f g a -> b # foldl' :: (b -> a -> b) -> b -> Sum f g a -> b # foldr1 :: (a -> a -> a) -> Sum f g a -> a # foldl1 :: (a -> a -> a) -> Sum f g a -> a # elem :: Eq a => a -> Sum f g a -> Bool # maximum :: Ord a => Sum f g a -> a # minimum :: Ord a => Sum f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :*: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :*: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :*: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :*: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :*: g) a -> b # foldr1 :: (a -> a -> a) -> (f :*: g) a -> a # foldl1 :: (a -> a -> a) -> (f :*: g) a -> a # toList :: (f :*: g) a -> [a] # length :: (f :*: g) a -> Int # elem :: Eq a => a -> (f :*: g) a -> Bool # maximum :: Ord a => (f :*: g) a -> a # minimum :: Ord a => (f :*: g) a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :+: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :+: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :+: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b # foldr1 :: (a -> a -> a) -> (f :+: g) a -> a # foldl1 :: (a -> a -> a) -> (f :+: g) a -> a # toList :: (f :+: g) a -> [a] # length :: (f :+: g) a -> Int # elem :: Eq a => a -> (f :+: g) a -> Bool # maximum :: Ord a => (f :+: g) a -> a # minimum :: Ord a => (f :+: g) a -> a # | |
| Foldable (K1 i c :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => K1 i c m -> m # foldMap :: Monoid m => (a -> m) -> K1 i c a -> m # foldMap' :: Monoid m => (a -> m) -> K1 i c a -> m # foldr :: (a -> b -> b) -> b -> K1 i c a -> b # foldr' :: (a -> b -> b) -> b -> K1 i c a -> b # foldl :: (b -> a -> b) -> b -> K1 i c a -> b # foldl' :: (b -> a -> b) -> b -> K1 i c a -> b # foldr1 :: (a -> a -> a) -> K1 i c a -> a # foldl1 :: (a -> a -> a) -> K1 i c a -> a # elem :: Eq a => a -> K1 i c a -> Bool # maximum :: Ord a => K1 i c a -> a # minimum :: Ord a => K1 i c a -> a # | |
| Foldable (Cited t f m) Source # | |
Defined in Nix.Cited.Basic Methods fold :: Monoid m0 => Cited t f m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Cited t f m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Cited t f m a -> m0 # foldr :: (a -> b -> b) -> b -> Cited t f m a -> b # foldr' :: (a -> b -> b) -> b -> Cited t f m a -> b # foldl :: (b -> a -> b) -> b -> Cited t f m a -> b # foldl' :: (b -> a -> b) -> b -> Cited t f m a -> b # foldr1 :: (a -> a -> a) -> Cited t f m a -> a # foldl1 :: (a -> a -> a) -> Cited t f m a -> a # toList :: Cited t f m a -> [a] # null :: Cited t f m a -> Bool # length :: Cited t f m a -> Int # elem :: Eq a => a -> Cited t f m a -> Bool # maximum :: Ord a => Cited t f m a -> a # minimum :: Ord a => Cited t f m a -> a # | |
| Foldable f => Foldable (NValue' t f m) Source # | |
Defined in Nix.Value Methods fold :: Monoid m0 => NValue' t f m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> NValue' t f m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> NValue' t f m a -> m0 # foldr :: (a -> b -> b) -> b -> NValue' t f m a -> b # foldr' :: (a -> b -> b) -> b -> NValue' t f m a -> b # foldl :: (b -> a -> b) -> b -> NValue' t f m a -> b # foldl' :: (b -> a -> b) -> b -> NValue' t f m a -> b # foldr1 :: (a -> a -> a) -> NValue' t f m a -> a # foldl1 :: (a -> a -> a) -> NValue' t f m a -> a # toList :: NValue' t f m a -> [a] # null :: NValue' t f m a -> Bool # length :: NValue' t f m a -> Int # elem :: Eq a => a -> NValue' t f m a -> Bool # maximum :: Ord a => NValue' t f m a -> a # minimum :: Ord a => NValue' t f m a -> a # | |
| (Foldable f, Foldable g) => Foldable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # | |
| (Foldable f, Foldable g) => Foldable (f :.: g) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => (f :.: g) m -> m # foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldMap' :: Monoid m => (a -> m) -> (f :.: g) a -> m # foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b # foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b # foldr1 :: (a -> a -> a) -> (f :.: g) a -> a # foldl1 :: (a -> a -> a) -> (f :.: g) a -> a # toList :: (f :.: g) a -> [a] # length :: (f :.: g) a -> Int # elem :: Eq a => a -> (f :.: g) a -> Bool # maximum :: Ord a => (f :.: g) a -> a # minimum :: Ord a => (f :.: g) a -> a # | |
| Foldable f => Foldable (M1 i c f) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => M1 i c f m -> m # foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m # foldMap' :: Monoid m => (a -> m) -> M1 i c f a -> m # foldr :: (a -> b -> b) -> b -> M1 i c f a -> b # foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b # foldl :: (b -> a -> b) -> b -> M1 i c f a -> b # foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b # foldr1 :: (a -> a -> a) -> M1 i c f a -> a # foldl1 :: (a -> a -> a) -> M1 i c f a -> a # elem :: Eq a => a -> M1 i c f a -> Bool # maximum :: Ord a => M1 i c f a -> a # minimum :: Ord a => M1 i c f a -> a # | |
| Foldable (Clown f a :: TYPE LiftedRep -> Type) | |
Defined in Data.Bifunctor.Clown Methods fold :: Monoid m => Clown f a m -> m # foldMap :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Clown f a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Clown f a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Clown f a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Clown f a a0 -> a0 # toList :: Clown f a a0 -> [a0] # null :: Clown f a a0 -> Bool # length :: Clown f a a0 -> Int # elem :: Eq a0 => a0 -> Clown f a a0 -> Bool # maximum :: Ord a0 => Clown f a a0 -> a0 # minimum :: Ord a0 => Clown f a a0 -> a0 # | |
| Bifoldable p => Foldable (Flip p a) | |
Defined in Data.Bifunctor.Flip Methods fold :: Monoid m => Flip p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Flip p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Flip p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Flip p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Flip p a a0 -> a0 # toList :: Flip p a a0 -> [a0] # length :: Flip p a a0 -> Int # elem :: Eq a0 => a0 -> Flip p a a0 -> Bool # maximum :: Ord a0 => Flip p a a0 -> a0 # minimum :: Ord a0 => Flip p a a0 -> a0 # | |
| Foldable g => Foldable (Joker g a) | |
Defined in Data.Bifunctor.Joker Methods fold :: Monoid m => Joker g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Joker g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Joker g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Joker g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Joker g a a0 -> a0 # toList :: Joker g a a0 -> [a0] # null :: Joker g a a0 -> Bool # length :: Joker g a a0 -> Int # elem :: Eq a0 => a0 -> Joker g a a0 -> Bool # maximum :: Ord a0 => Joker g a a0 -> a0 # minimum :: Ord a0 => Joker g a a0 -> a0 # | |
| Bifoldable p => Foldable (WrappedBifunctor p a) | |
Defined in Data.Bifunctor.Wrapped Methods fold :: Monoid m => WrappedBifunctor p a m -> m # foldMap :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> WrappedBifunctor p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> WrappedBifunctor p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> WrappedBifunctor p a a0 -> a0 # toList :: WrappedBifunctor p a a0 -> [a0] # null :: WrappedBifunctor p a a0 -> Bool # length :: WrappedBifunctor p a a0 -> Int # elem :: Eq a0 => a0 -> WrappedBifunctor p a a0 -> Bool # maximum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # minimum :: Ord a0 => WrappedBifunctor p a a0 -> a0 # sum :: Num a0 => WrappedBifunctor p a a0 -> a0 # product :: Num a0 => WrappedBifunctor p a a0 -> a0 # | |
| (Foldable (f a), Foldable (g a)) => Foldable (Product f g a) | |
Defined in Data.Bifunctor.Product Methods fold :: Monoid m => Product f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Product f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Product f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Product f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Product f g a a0 -> a0 # toList :: Product f g a a0 -> [a0] # null :: Product f g a a0 -> Bool # length :: Product f g a a0 -> Int # elem :: Eq a0 => a0 -> Product f g a a0 -> Bool # maximum :: Ord a0 => Product f g a a0 -> a0 # minimum :: Ord a0 => Product f g a a0 -> a0 # | |
| (Foldable (f a), Foldable (g a)) => Foldable (Sum f g a) | |
Defined in Data.Bifunctor.Sum Methods fold :: Monoid m => Sum f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Sum f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Sum f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Sum f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Sum f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Sum f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Sum f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Sum f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Sum f g a a0 -> a0 # toList :: Sum f g a a0 -> [a0] # null :: Sum f g a a0 -> Bool # length :: Sum f g a a0 -> Int # elem :: Eq a0 => a0 -> Sum f g a a0 -> Bool # maximum :: Ord a0 => Sum f g a a0 -> a0 # minimum :: Ord a0 => Sum f g a a0 -> a0 # | |
| (Foldable f, Bifoldable p) => Foldable (Tannen f p a) | |
Defined in Data.Bifunctor.Tannen Methods fold :: Monoid m => Tannen f p a m -> m # foldMap :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Tannen f p a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Tannen f p a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Tannen f p a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Tannen f p a a0 -> a0 # toList :: Tannen f p a a0 -> [a0] # null :: Tannen f p a a0 -> Bool # length :: Tannen f p a a0 -> Int # elem :: Eq a0 => a0 -> Tannen f p a a0 -> Bool # maximum :: Ord a0 => Tannen f p a a0 -> a0 # minimum :: Ord a0 => Tannen f p a a0 -> a0 # | |
| (Bifoldable p, Foldable g) => Foldable (Biff p f g a) | |
Defined in Data.Bifunctor.Biff Methods fold :: Monoid m => Biff p f g a m -> m # foldMap :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Biff p f g a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Biff p f g a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Biff p f g a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Biff p f g a a0 -> a0 # toList :: Biff p f g a a0 -> [a0] # null :: Biff p f g a a0 -> Bool # length :: Biff p f g a a0 -> Int # elem :: Eq a0 => a0 -> Biff p f g a a0 -> Bool # maximum :: Ord a0 => Biff p f g a a0 -> a0 # minimum :: Ord a0 => Biff p f g a a0 -> a0 # | |
class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where #
Functors representing data structures that can be transformed to
structures of the same shape by performing an Applicative (or,
therefore, Monad) action on each element from left to right.
A more detailed description of what same shape means, the various methods, how traversals are constructed, and example advanced use-cases can be found in the Overview section of Data.Traversable.
For the class laws see the Laws section of Data.Traversable.
Methods
traverse :: Applicative f => (a -> f b) -> t a -> f (t b) #
Map each element of a structure to an action, evaluate these actions
from left to right, and collect the results. For a version that ignores
the results see traverse_.
Examples
Basic usage:
In the first two examples we show each evaluated action mapping to the output structure.
>>>traverse Just [1,2,3,4]Just [1,2,3,4]
>>>traverse id [Right 1, Right 2, Right 3, Right 4]Right [1,2,3,4]
In the next examples, we show that Nothing and Left values short
circuit the created structure.
>>>traverse (const Nothing) [1,2,3,4]Nothing
>>>traverse (\x -> if odd x then Just x else Nothing) [1,2,3,4]Nothing
>>>traverse id [Right 1, Right 2, Right 3, Right 4, Left 0]Left 0
sequenceA :: Applicative f => t (f a) -> f (t a) #
Evaluate each action in the structure from left to right, and
collect the results. For a version that ignores the results
see sequenceA_.
Examples
Basic usage:
For the first two examples we show sequenceA fully evaluating a a structure and collecting the results.
>>>sequenceA [Just 1, Just 2, Just 3]Just [1,2,3]
>>>sequenceA [Right 1, Right 2, Right 3]Right [1,2,3]
The next two example show Nothing and Just will short circuit
the resulting structure if present in the input. For more context,
check the Traversable instances for Either and Maybe.
>>>sequenceA [Just 1, Just 2, Just 3, Nothing]Nothing
>>>sequenceA [Right 1, Right 2, Right 3, Left 4]Left 4
mapM :: Monad m => (a -> m b) -> t a -> m (t b) #
Map each element of a structure to a monadic action, evaluate
these actions from left to right, and collect the results. For
a version that ignores the results see mapM_.
Examples
sequence :: Monad m => t (m a) -> m (t a) #
Evaluate each monadic action in the structure from left to
right, and collect the results. For a version that ignores the
results see sequence_.
Examples
Basic usage:
The first two examples are instances where the input and
and output of sequence are isomorphic.
>>>sequence $ Right [1,2,3,4][Right 1,Right 2,Right 3,Right 4]
>>>sequence $ [Right 1,Right 2,Right 3,Right 4]Right [1,2,3,4]
The following examples demonstrate short circuit behavior
for sequence.
>>>sequence $ Left [1,2,3,4]Left [1,2,3,4]
>>>sequence $ [Left 0, Right 1,Right 2,Right 3,Right 4]Left 0
Instances
Representable types of kind *.
This class is derivable in GHC with the DeriveGeneric flag on.
A Generic instance must satisfy the following laws:
from.to≡idto.from≡id
Instances
This class gives the integer associated with a type-level natural. There are instances of the class for every concrete literal: 0, 1, 2, etc.
Since: base-4.7.0.0
Minimal complete definition
natSing
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Minimal complete definition
Methods
(<>) :: a -> a -> a infixr 6 #
An associative operation.
>>>[1,2,3] <> [4,5,6][1,2,3,4,5,6]
Reduce a non-empty list with <>
The default definition should be sufficient, but this can be overridden for efficiency.
>>>import Data.List.NonEmpty (NonEmpty (..))>>>sconcat $ "Hello" :| [" ", "Haskell", "!"]"Hello Haskell!"
stimes :: Integral b => b -> a -> a #
Repeat a value n times.
Given that this works on a Semigroup it is allowed to fail if
you request 0 or fewer repetitions, and the default definition
will do so.
By making this a member of the class, idempotent semigroups
and monoids can upgrade this to execute in \(\mathcal{O}(1)\) by
picking stimes = or stimesIdempotentstimes =
respectively.stimesIdempotentMonoid
>>>stimes 4 [1][1,1,1,1]
Instances
class Semigroup a => Monoid a where #
The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:
- Right identity
x<>mempty= x- Left identity
mempty<>x = x- Associativity
x(<>(y<>z) = (x<>y)<>zSemigrouplaw)- Concatenation
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtypes and make those instances
of Monoid, e.g. Sum and Product.
NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.
Minimal complete definition
Methods
Identity of mappend
>>>"Hello world" <> mempty"Hello world"
An associative operation
NOTE: This method is redundant and has the default
implementation mappend = (<>)mappend is a synonym for
(<>), it is expected that the two functions are defined the same
way. In a future GHC release mappend will be removed from Monoid.
Fold a list using the monoid.
For most types, the default definition for mconcat will be
used, but the function is included in the class definition so
that an optimized version can be provided for specific types.
>>>mconcat ["Hello", " ", "Haskell", "!"]"Hello Haskell!"
Instances
Instances
The character type Char is an enumeration whose values represent
Unicode (or equivalently ISO/IEC 10646) code points (i.e. characters, see
http://www.unicode.org/ for details). This set extends the ISO 8859-1
(Latin-1) character set (the first 256 characters), which is itself an extension
of the ASCII character set (the first 128 characters). A character literal in
Haskell has type Char.
To convert a Char to or from the corresponding Int value defined
by Unicode, use toEnum and fromEnum from the
Enum class respectively (or equivalently ord and
chr).
Instances
Double-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE double-precision type.
Instances
Single-precision floating point numbers. It is desirable that this type be at least equal in range and precision to the IEEE single-precision type.
Instances
| FromJSON Float | |
| FromJSONKey Float | |
Defined in Data.Aeson.Types.FromJSON | |
| ToJSON Float | |
Defined in Data.Aeson.Types.ToJSON | |
| ToJSONKey Float | |
Defined in Data.Aeson.Types.ToJSON | |
| Data Float | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Float -> c Float # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Float # dataTypeOf :: Float -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Float) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Float) # gmapT :: (forall b. Data b => b -> b) -> Float -> Float # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Float -> r # gmapQ :: (forall d. Data d => d -> u) -> Float -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Float -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Float -> m Float # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Float -> m Float # | |
| Storable Float | Since: base-2.1 |
| Floating Float | Since: base-2.1 |
| RealFloat Float | Since: base-2.1 |
Defined in GHC.Float Methods floatRadix :: Float -> Integer # floatDigits :: Float -> Int # floatRange :: Float -> (Int, Int) # decodeFloat :: Float -> (Integer, Int) # encodeFloat :: Integer -> Int -> Float # significand :: Float -> Float # scaleFloat :: Int -> Float -> Float # isInfinite :: Float -> Bool # isDenormalized :: Float -> Bool # isNegativeZero :: Float -> Bool # | |
| Read Float | Since: base-2.1 |
| Subtractive Float | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Float # | |
| PrimType Float | |
Defined in Basement.PrimType Methods primSizeInBytes :: Proxy Float -> CountOf Word8 # primShiftToBytes :: Proxy Float -> Int # primBaUIndex :: ByteArray# -> Offset Float -> Float # primMbaURead :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Float -> prim Float # primMbaUWrite :: PrimMonad prim => MutableByteArray# (PrimState prim) -> Offset Float -> Float -> prim () # primAddrIndex :: Addr# -> Offset Float -> Float # primAddrRead :: PrimMonad prim => Addr# -> Offset Float -> prim Float # primAddrWrite :: PrimMonad prim => Addr# -> Offset Float -> Float -> prim () # | |
| Binary Float | |
| NFData Float | |
Defined in Control.DeepSeq | |
| Eq Float | Note that due to the presence of
Also note that
|
| Ord Float | Note that due to the presence of
Also note that, due to the same,
|
| Hashable Float | Note: prior to The Since: hashable-1.3.0.0 |
Defined in Data.Hashable.Class | |
| ToExpr Float Source # | |
| Pretty Float |
|
Defined in Prettyprinter.Internal | |
| Prim Float | |
Defined in Data.Primitive.Types Methods alignment# :: Float -> Int# # indexByteArray# :: ByteArray# -> Int# -> Float # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Float #) # writeByteArray# :: MutableByteArray# s -> Int# -> Float -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Float -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Float # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Float #) # writeOffAddr# :: Addr# -> Int# -> Float -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Float -> State# s -> State# s # | |
| UniformRange Float | |
Defined in System.Random.Internal | |
| Serialise Float | Since: serialise-0.2.0.0 |
| Unbox Float | |
Defined in Data.Vector.Unboxed.Base | |
| IArray UArray Float | |
Defined in Data.Array.Base Methods bounds :: Ix i => UArray i Float -> (i, i) # numElements :: Ix i => UArray i Float -> Int unsafeArray :: Ix i => (i, i) -> [(Int, Float)] -> UArray i Float unsafeAt :: Ix i => UArray i Float -> Int -> Float unsafeReplace :: Ix i => UArray i Float -> [(Int, Float)] -> UArray i Float unsafeAccum :: Ix i => (Float -> e' -> Float) -> UArray i Float -> [(Int, e')] -> UArray i Float unsafeAccumArray :: Ix i => (Float -> e' -> Float) -> Float -> (i, i) -> [(Int, e')] -> UArray i Float | |
| Lift Float | |
| Vector Vector Float | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Float -> ST s (Vector Float) # basicUnsafeThaw :: Vector Float -> ST s (Mutable Vector s Float) # basicLength :: Vector Float -> Int # basicUnsafeSlice :: Int -> Int -> Vector Float -> Vector Float # basicUnsafeIndexM :: Vector Float -> Int -> Box Float # basicUnsafeCopy :: Mutable Vector s Float -> Vector Float -> ST s () # | |
| MVector MVector Float | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Float -> Int # basicUnsafeSlice :: Int -> Int -> MVector s Float -> MVector s Float # basicOverlaps :: MVector s Float -> MVector s Float -> Bool # basicUnsafeNew :: Int -> ST s (MVector s Float) # basicInitialize :: MVector s Float -> ST s () # basicUnsafeReplicate :: Int -> Float -> ST s (MVector s Float) # basicUnsafeRead :: MVector s Float -> Int -> ST s Float # basicUnsafeWrite :: MVector s Float -> Int -> Float -> ST s () # basicClear :: MVector s Float -> ST s () # basicSet :: MVector s Float -> Float -> ST s () # basicUnsafeCopy :: MVector s Float -> MVector s Float -> ST s () # basicUnsafeMove :: MVector s Float -> MVector s Float -> ST s () # basicUnsafeGrow :: MVector s Float -> Int -> ST s (MVector s Float) # | |
| Convertible e t f m => FromValue Float m (NValue' t f m (NValue t f m)) Source # | |
| Convertible e t f m => ToValue Float m (NValue' t f m (NValue t f m)) Source # | |
| Generic1 (URec Float :: k -> Type) | |
| Foldable (UFloat :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => UFloat m -> m # foldMap :: Monoid m => (a -> m) -> UFloat a -> m # foldMap' :: Monoid m => (a -> m) -> UFloat a -> m # foldr :: (a -> b -> b) -> b -> UFloat a -> b # foldr' :: (a -> b -> b) -> b -> UFloat a -> b # foldl :: (b -> a -> b) -> b -> UFloat a -> b # foldl' :: (b -> a -> b) -> b -> UFloat a -> b # foldr1 :: (a -> a -> a) -> UFloat a -> a # foldl1 :: (a -> a -> a) -> UFloat a -> a # elem :: Eq a => a -> UFloat a -> Bool # maximum :: Ord a => UFloat a -> a # minimum :: Ord a => UFloat a -> a # | |
| Traversable (UFloat :: Type -> Type) | Since: base-4.9.0.0 |
| MArray (STUArray s) Float (ST s) | |
Defined in Data.Array.Base Methods getBounds :: Ix i => STUArray s i Float -> ST s (i, i) # getNumElements :: Ix i => STUArray s i Float -> ST s Int newArray :: Ix i => (i, i) -> Float -> ST s (STUArray s i Float) # newArray_ :: Ix i => (i, i) -> ST s (STUArray s i Float) # unsafeNewArray_ :: Ix i => (i, i) -> ST s (STUArray s i Float) unsafeRead :: Ix i => STUArray s i Float -> Int -> ST s Float unsafeWrite :: Ix i => STUArray s i Float -> Int -> Float -> ST s () | |
| Functor (URec Float :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
| Generic (URec Float p) | |
| Show (URec Float p) | |
| Eq (URec Float p) | |
| Ord (URec Float p) | |
Defined in GHC.Generics | |
| type Difference Float | |
Defined in Basement.Numerical.Subtractive | |
| type PrimSize Float | |
Defined in Basement.PrimType | |
| newtype Vector Float | |
| data URec Float (p :: k) | Used for marking occurrences of Since: base-4.9.0.0 |
| newtype MVector s Float | |
| type Rep1 (URec Float :: k -> Type) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| type Rep (URec Float p) | |
Defined in GHC.Generics | |
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1].
The exact range for a given implementation can be determined by using
minBound and maxBound from the Bounded class.
Instances
8-bit signed integer type
Instances
16-bit signed integer type
Instances
32-bit signed integer type
Instances
64-bit signed integer type
Instances
Arbitrary precision integers. In contrast with fixed-size integral types
such as Int, the Integer type represents the entire infinite range of
integers.
Integers are stored in a kind of sign-magnitude form, hence do not expect two's complement form when using bit operations.
If the value is small (fit into an Int), IS constructor is used.
Otherwise Integer and IN constructors are used to store a BigNat
representing respectively the positive or the negative value magnitude.
Invariant: Integer and IN are used iff value doesn't fit in IS
Instances
| FromJSON Integer | This instance includes a bounds check to prevent maliciously
large inputs to fill up the memory of the target system. You can
newtype |
| FromJSONKey Integer | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| ToJSON Integer | |
Defined in Data.Aeson.Types.ToJSON | |
| ToJSONKey Integer | |
Defined in Data.Aeson.Types.ToJSON | |
| Data Integer | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Integer -> c Integer # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Integer # toConstr :: Integer -> Constr # dataTypeOf :: Integer -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Integer) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Integer) # gmapT :: (forall b. Data b => b -> b) -> Integer -> Integer # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Integer -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Integer -> r # gmapQ :: (forall d. Data d => d -> u) -> Integer -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Integer -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Integer -> m Integer # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Integer -> m Integer # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Integer -> m Integer # | |
| Bits Integer | Since: base-2.1 |
Defined in GHC.Bits Methods (.&.) :: Integer -> Integer -> Integer # (.|.) :: Integer -> Integer -> Integer # xor :: Integer -> Integer -> Integer # complement :: Integer -> Integer # shift :: Integer -> Int -> Integer # rotate :: Integer -> Int -> Integer # setBit :: Integer -> Int -> Integer # clearBit :: Integer -> Int -> Integer # complementBit :: Integer -> Int -> Integer # testBit :: Integer -> Int -> Bool # bitSizeMaybe :: Integer -> Maybe Int # shiftL :: Integer -> Int -> Integer # unsafeShiftL :: Integer -> Int -> Integer # shiftR :: Integer -> Int -> Integer # unsafeShiftR :: Integer -> Int -> Integer # rotateL :: Integer -> Int -> Integer # | |
| Enum Integer | Since: base-2.1 |
| Ix Integer | Since: base-2.1 |
Defined in GHC.Ix | |
| Num Integer | Since: base-2.1 |
| Read Integer | Since: base-2.1 |
| Integral Integer | Since: base-2.0.1 |
Defined in GHC.Real | |
| Real Integer | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Integer -> Rational # | |
| Show Integer | Since: base-2.1 |
| Subtractive Integer | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Integer # | |
| Binary Integer | |
| NFData Integer | |
Defined in Control.DeepSeq | |
| Eq Integer | |
| Ord Integer | |
| Hashable Integer | |
Defined in Data.Hashable.Class | |
| ToExpr Integer Source # | |
| Pretty Integer |
|
Defined in Prettyprinter.Internal | |
| UniformRange Integer | |
Defined in System.Random.Internal | |
| Serialise Integer | Since: serialise-0.2.0.0 |
| Lift Integer | |
| Convertible e t f m => FromValue Integer m (NValue' t f m (NValue t f m)) Source # | |
| Convertible e t f m => ToValue Integer m (NValue' t f m (NValue t f m)) Source # | |
| type Difference Integer | |
Defined in Basement.Numerical.Subtractive | |
Natural number
Invariant: numbers <= 0xffffffffffffffff use the NS constructor
Instances
| FromJSON Natural | |
| FromJSONKey Natural | |
Defined in Data.Aeson.Types.FromJSON Methods | |
| ToJSON Natural | |
Defined in Data.Aeson.Types.ToJSON | |
| ToJSONKey Natural | |
Defined in Data.Aeson.Types.ToJSON | |
| Data Natural | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Natural -> c Natural # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Natural # toConstr :: Natural -> Constr # dataTypeOf :: Natural -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Natural) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Natural) # gmapT :: (forall b. Data b => b -> b) -> Natural -> Natural # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Natural -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Natural -> r # gmapQ :: (forall d. Data d => d -> u) -> Natural -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Natural -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Natural -> m Natural # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Natural -> m Natural # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Natural -> m Natural # | |
| Bits Natural | Since: base-4.8.0 |
Defined in GHC.Bits Methods (.&.) :: Natural -> Natural -> Natural # (.|.) :: Natural -> Natural -> Natural # xor :: Natural -> Natural -> Natural # complement :: Natural -> Natural # shift :: Natural -> Int -> Natural # rotate :: Natural -> Int -> Natural # setBit :: Natural -> Int -> Natural # clearBit :: Natural -> Int -> Natural # complementBit :: Natural -> Int -> Natural # testBit :: Natural -> Int -> Bool # bitSizeMaybe :: Natural -> Maybe Int # shiftL :: Natural -> Int -> Natural # unsafeShiftL :: Natural -> Int -> Natural # shiftR :: Natural -> Int -> Natural # unsafeShiftR :: Natural -> Int -> Natural # rotateL :: Natural -> Int -> Natural # | |
| Enum Natural | Since: base-4.8.0.0 |
| Ix Natural | Since: base-4.8.0.0 |
Defined in GHC.Ix | |
| Num Natural | Note that Since: base-4.8.0.0 |
| Read Natural | Since: base-4.8.0.0 |
| Integral Natural | Since: base-4.8.0.0 |
Defined in GHC.Real | |
| Real Natural | Since: base-4.8.0.0 |
Defined in GHC.Real Methods toRational :: Natural -> Rational # | |
| Show Natural | Since: base-4.8.0.0 |
| Subtractive Natural | |
Defined in Basement.Numerical.Subtractive Associated Types type Difference Natural # | |
| Binary Natural | Since: binary-0.7.3.0 |
| NFData Natural | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq Natural | |
| Ord Natural | |
| Hashable Natural | |
Defined in Data.Hashable.Class | |
| Pretty Natural | |
Defined in Prettyprinter.Internal | |
| UniformRange Natural | |
Defined in System.Random.Internal | |
| Serialise Natural | Since: serialise-0.2.0.0 |
| KnownNat n => HasResolution (n :: Nat) | For example, |
Defined in Data.Fixed Methods resolution :: p n -> Integer # | |
| Lift Natural | |
| type Difference Natural | |
Defined in Basement.Numerical.Subtractive | |
| type Compare (a :: Natural) (b :: Natural) | |
Defined in Data.Type.Ord | |
The Maybe type encapsulates an optional value. A value of type
Maybe aa (represented as Just aNothing). Using Maybe is a good way to
deal with errors or exceptional cases without resorting to drastic
measures such as error.
The Maybe type is also a monad. It is a simple kind of error
monad, where all errors are represented by Nothing. A richer
error monad can be built using the Either type.
Instances
| FromJSON1 Maybe | |
| ToJSON1 Maybe | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Maybe a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Maybe a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Maybe a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Maybe a] -> Encoding # | |
| MonadFail Maybe | Since: base-4.9.0.0 |
Defined in Control.Monad.Fail | |
| MonadFix Maybe | Since: base-2.1 |
Defined in Control.Monad.Fix | |
| Foldable Maybe | Since: base-2.1 |
Defined in Data.Foldable Methods fold :: Monoid m => Maybe m -> m # foldMap :: Monoid m => (a -> m) -> Maybe a -> m # foldMap' :: Monoid m => (a -> m) -> Maybe a -> m # foldr :: (a -> b -> b) -> b -> Maybe a -> b # foldr' :: (a -> b -> b) -> b -> Maybe a -> b # foldl :: (b -> a -> b) -> b -> Maybe a -> b # foldl' :: (b -> a -> b) -> b -> Maybe a -> b # foldr1 :: (a -> a -> a) -> Maybe a -> a # foldl1 :: (a -> a -> a) -> Maybe a -> a # elem :: Eq a => a -> Maybe a -> Bool # maximum :: Ord a => Maybe a -> a # minimum :: Ord a => Maybe a -> a # | |
| Eq1 Maybe | Since: base-4.9.0.0 |
| Ord1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read1 Maybe | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Show1 Maybe | Since: base-4.9.0.0 |
| Traversable Maybe | Since: base-2.1 |
| Alternative Maybe | Since: base-2.1 |
| Applicative Maybe | Since: base-2.1 |
| Functor Maybe | Since: base-2.1 |
| Monad Maybe | Since: base-2.1 |
| MonadPlus Maybe | Since: base-2.1 |
| MonadFailure Maybe | |
| NFData1 Maybe | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| MonadThrow Maybe | |
Defined in Control.Monad.Catch | |
| Hashable1 Maybe | |
Defined in Data.Hashable.Class | |
| Align Maybe | |
Defined in Data.Semialign.Internal | |
| Repeat Maybe | |
Defined in Data.Semialign.Internal | |
| Semialign Maybe | |
| Unalign Maybe | |
| Unzip Maybe | |
| Zip Maybe | |
| Generic1 Maybe | |
| FoldableWithIndex () Maybe | |
| FunctorWithIndex () Maybe | |
| TraversableWithIndex () Maybe | |
| MonadBaseControl Maybe Maybe | |
| MonadError () Maybe | Since: mtl-2.2.2 |
Defined in Control.Monad.Error.Class | |
| RepeatWithIndex () Maybe | |
Defined in Data.Semialign.Internal | |
| SemialignWithIndex () Maybe | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex () Maybe | |
| MonadBase Maybe Maybe | |
Defined in Control.Monad.Base | |
| (Selector s, GToJSON' enc arity (K1 i (Maybe a) :: TYPE LiftedRep -> Type), KeyValuePair enc pairs, Monoid pairs) => RecordToPairs enc pairs arity (S1 s (K1 i (Maybe a) :: TYPE LiftedRep -> Type)) | |
Defined in Data.Aeson.Types.ToJSON | |
| Lift a => Lift (Maybe a :: Type) | |
| (Selector s, FromJSON a) => RecordFromJSON' arity (S1 s (K1 i (Maybe a) :: Type -> Type)) | |
Defined in Data.Aeson.Types.FromJSON | |
| LookupField (Maybe a) | |
| FromJSON a => FromJSON (Maybe a) | |
| ToJSON a => ToJSON (Maybe a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Maybe a) | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Maybe a -> c (Maybe a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Maybe a) # toConstr :: Maybe a -> Constr # dataTypeOf :: Maybe a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Maybe a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Maybe a)) # gmapT :: (forall b. Data b => b -> b) -> Maybe a -> Maybe a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r # gmapQ :: (forall d. Data d => d -> u) -> Maybe a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Maybe a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) # | |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Semigroup a => Semigroup (Maybe a) | Since: base-4.9.0.0 |
| Generic (Maybe a) | |
| SingKind a => SingKind (Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics Associated Types type DemoteRep (Maybe a) | |
| Read a => Read (Maybe a) | Since: base-2.1 |
| Show a => Show (Maybe a) | Since: base-2.1 |
| Binary a => Binary (Maybe a) | |
| NFData a => NFData (Maybe a) | |
Defined in Control.DeepSeq | |
| Eq a => Eq (Maybe a) | Since: base-2.1 |
| Ord a => Ord (Maybe a) | Since: base-2.1 |
| Hashable a => Hashable (Maybe a) | |
Defined in Data.Hashable.Class | |
| ToExpr a => ToExpr (Maybe a) Source # | |
| (QueryKeyLike k, QueryValueLike v) => QueryLike [Maybe (k, v)] | |
Defined in Network.HTTP.Types.QueryLike | |
| QueryValueLike a => QueryValueLike (Maybe a) | |
Defined in Network.HTTP.Types.QueryLike Methods toQueryValue :: Maybe a -> Maybe ByteString # | |
| Pretty a => Pretty (Maybe a) | Ignore
|
Defined in Prettyprinter.Internal | |
| Serialise a => Serialise (Maybe a) | Since: serialise-0.2.0.0 |
| SingI ('Nothing :: Maybe a) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| SingI a2 => SingI ('Just a2 :: Maybe a1) | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| type Failure Maybe | |
Defined in Basement.Monad | |
| type Rep1 Maybe | Since: base-4.6.0.0 |
| type StM Maybe a | |
Defined in Control.Monad.Trans.Control | |
| type DemoteRep (Maybe a) | |
Defined in GHC.Generics | |
| type Rep (Maybe a) | Since: base-4.6.0.0 |
Defined in GHC.Generics | |
| data Sing (b :: Maybe a) | |
Instances
| FromJSON Ordering | |
| ToJSON Ordering | |
Defined in Data.Aeson.Types.ToJSON | |
| Data Ordering | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ordering -> c Ordering # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Ordering # toConstr :: Ordering -> Constr # dataTypeOf :: Ordering -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Ordering) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Ordering) # gmapT :: (forall b. Data b => b -> b) -> Ordering -> Ordering # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r # gmapQ :: (forall d. Data d => d -> u) -> Ordering -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Ordering -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering # | |
| Monoid Ordering | Since: base-2.1 |
| Semigroup Ordering | Since: base-4.9.0.0 |
| Bounded Ordering | Since: base-2.1 |
| Enum Ordering | Since: base-2.1 |
| Generic Ordering | |
| Ix Ordering | Since: base-2.1 |
Defined in GHC.Ix Methods range :: (Ordering, Ordering) -> [Ordering] # index :: (Ordering, Ordering) -> Ordering -> Int # unsafeIndex :: (Ordering, Ordering) -> Ordering -> Int # inRange :: (Ordering, Ordering) -> Ordering -> Bool # rangeSize :: (Ordering, Ordering) -> Int # unsafeRangeSize :: (Ordering, Ordering) -> Int # | |
| Read Ordering | Since: base-2.1 |
| Show Ordering | Since: base-2.1 |
| Binary Ordering | |
| NFData Ordering | |
Defined in Control.DeepSeq | |
| Eq Ordering | |
| Ord Ordering | |
Defined in GHC.Classes | |
| Hashable Ordering | |
Defined in Data.Hashable.Class | |
| Serialise Ordering | Since: serialise-0.2.0.0 |
| type Rep Ordering | Since: base-4.6.0.0 |
Rational numbers, with numerator and denominator of some Integral type.
Note that Ratio's instances inherit the deficiencies from the type
parameter's. For example, Ratio Natural's Num instance has similar
problems to Natural's.
Instances
| NFData1 Ratio | Available on Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Integral a => Lift (Ratio a :: Type) | |
| (FromJSON a, Integral a) => FromJSON (Ratio a) | |
| (ToJSON a, Integral a) => ToJSON (Ratio a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Integral a) => Data (Ratio a) | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ratio a -> c (Ratio a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Ratio a) # toConstr :: Ratio a -> Constr # dataTypeOf :: Ratio a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Ratio a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Ratio a)) # gmapT :: (forall b. Data b => b -> b) -> Ratio a -> Ratio a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ratio a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ratio a -> r # gmapQ :: (forall d. Data d => d -> u) -> Ratio a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Ratio a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ratio a -> m (Ratio a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ratio a -> m (Ratio a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ratio a -> m (Ratio a) # | |
| (Storable a, Integral a) => Storable (Ratio a) | Since: base-4.8.0.0 |
| Integral a => Enum (Ratio a) | Since: base-2.0.1 |
| Integral a => Num (Ratio a) | Since: base-2.0.1 |
| (Integral a, Read a) => Read (Ratio a) | Since: base-2.1 |
| Integral a => Fractional (Ratio a) | Since: base-2.0.1 |
| Integral a => Real (Ratio a) | Since: base-2.0.1 |
Defined in GHC.Real Methods toRational :: Ratio a -> Rational # | |
| Integral a => RealFrac (Ratio a) | Since: base-2.0.1 |
| Show a => Show (Ratio a) | Since: base-2.0.1 |
| (Binary a, Integral a) => Binary (Ratio a) | |
| NFData a => NFData (Ratio a) | |
Defined in Control.DeepSeq | |
| Eq a => Eq (Ratio a) | Since: base-2.1 |
| Integral a => Ord (Ratio a) | Since: base-2.0.1 |
| Hashable a => Hashable (Ratio a) | |
Defined in Data.Hashable.Class | |
| (Serialise a, Integral a) => Serialise (Ratio a) | Since: serialise-0.2.0.0 |
A value of type IO aa.
There is really only one way to "perform" an I/O action: bind it to
Main.main in your program. When your program is run, the I/O will
be performed. It isn't possible to perform I/O from an arbitrary
function, unless that function is itself in the IO monad and called
at some point, directly or indirectly, from Main.main.
IO is a monad, so IO actions can be combined using either the do-notation
or the >> and >>= operations from the Monad
class.
Instances
Instances
8-bit unsigned integer type
Instances
16-bit unsigned integer type
Instances
32-bit unsigned integer type
Instances
64-bit unsigned integer type
Instances
The Either type represents values with two possibilities: a value of
type Either a bLeft aRight b
The Either type is sometimes used to represent a value which is
either correct or an error; by convention, the Left constructor is
used to hold an error value and the Right constructor is used to
hold a correct value (mnemonic: "right" also means "correct").
Examples
The type Either String IntString or an Int. The Left constructor can be used only on
Strings, and the Right constructor can be used only on Ints:
>>>let s = Left "foo" :: Either String Int>>>sLeft "foo">>>let n = Right 3 :: Either String Int>>>nRight 3>>>:type ss :: Either String Int>>>:type nn :: Either String Int
The fmap from our Functor instance will ignore Left values, but
will apply the supplied function to values contained in a Right:
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>fmap (*2) sLeft "foo">>>fmap (*2) nRight 6
The Monad instance for Either allows us to chain together multiple
actions which may fail, and fail overall if any of the individual
steps failed. First we'll write a function that can either parse an
Int from a Char, or fail.
>>>import Data.Char ( digitToInt, isDigit )>>>:{let parseEither :: Char -> Either String Int parseEither c | isDigit c = Right (digitToInt c) | otherwise = Left "parse error">>>:}
The following should work, since both '1' and '2' can be
parsed as Ints.
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither '1' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleRight 3
But the following should fail overall, since the first operation where
we attempt to parse 'm' as an Int will fail:
>>>:{let parseMultiple :: Either String Int parseMultiple = do x <- parseEither 'm' y <- parseEither '2' return (x + y)>>>:}
>>>parseMultipleLeft "parse error"
Instances
| FromJSON2 Either | |
Defined in Data.Aeson.Types.FromJSON | |
| ToJSON2 Either | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> Either a b -> Value # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [Either a b] -> Value # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> Either a b -> Encoding # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [Either a b] -> Encoding # | |
| Bifoldable Either | Since: base-4.10.0.0 |
| Bifunctor Either | Since: base-4.8.0.0 |
| Bitraversable Either | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) # | |
| Eq2 Either | Since: base-4.9.0.0 |
| Ord2 Either | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read2 Either | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] # | |
| Show2 Either | Since: base-4.9.0.0 |
| NFData2 Either | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable2 Either | |
Defined in Data.Hashable.Class | |
| Generic1 (Either a :: Type -> Type) | |
| MonadError e (Either e) | |
Defined in Control.Monad.Error.Class | |
| (Lift a, Lift b) => Lift (Either a b :: Type) | |
| FromJSON a => FromJSON1 (Either a) | |
| ToJSON a => ToJSON1 (Either a) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> Either a a0 -> Value # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [Either a a0] -> Value # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> Either a a0 -> Encoding # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [Either a a0] -> Encoding # | |
| MonadFix (Either e) | Since: base-4.3.0.0 |
Defined in Control.Monad.Fix | |
| Foldable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Either a m -> m # foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m # foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b # foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b # foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 # toList :: Either a a0 -> [a0] # length :: Either a a0 -> Int # elem :: Eq a0 => a0 -> Either a a0 -> Bool # maximum :: Ord a0 => Either a a0 -> a0 # minimum :: Ord a0 => Either a a0 -> a0 # | |
| Eq a => Eq1 (Either a) | Since: base-4.9.0.0 |
| Ord a => Ord1 (Either a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read a => Read1 (Either a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] # | |
| Show a => Show1 (Either a) | Since: base-4.9.0.0 |
| Traversable (Either a) | Since: base-4.7.0.0 |
Defined in Data.Traversable | |
| Applicative (Either e) | Since: base-3.0 |
| Functor (Either a) | Since: base-3.0 |
| Monad (Either e) | Since: base-4.4.0.0 |
| MonadFailure (Either a) | |
| NFData a => NFData1 (Either a) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| e ~ SomeException => MonadCatch (Either e) | Since: exceptions-0.8.3 |
| e ~ SomeException => MonadMask (Either e) | Since: exceptions-0.8.3 |
Defined in Control.Monad.Catch | |
| e ~ SomeException => MonadThrow (Either e) | |
Defined in Control.Monad.Catch | |
| Hashable a => Hashable1 (Either a) | |
Defined in Data.Hashable.Class | |
| MonadBaseControl (Either e) (Either e) | |
| MonadBase (Either e) (Either e) | |
Defined in Control.Monad.Base | |
| (FromJSON a, FromJSON b) => FromJSON (Either a b) | |
| (ToJSON a, ToJSON b) => ToJSON (Either a b) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Data b) => Data (Either a b) | Since: base-4.0.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Either a b -> c (Either a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Either a b) # toConstr :: Either a b -> Constr # dataTypeOf :: Either a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Either a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Either a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Either a b -> Either a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r # gmapQ :: (forall d. Data d => d -> u) -> Either a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Either a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) # | |
| Semigroup (Either a b) | Since: base-4.9.0.0 |
| Generic (Either a b) | |
| (Read a, Read b) => Read (Either a b) | Since: base-3.0 |
| (Show a, Show b) => Show (Either a b) | Since: base-3.0 |
| (Binary a, Binary b) => Binary (Either a b) | |
| (NFData a, NFData b) => NFData (Either a b) | |
Defined in Control.DeepSeq | |
| (Eq a, Eq b) => Eq (Either a b) | Since: base-2.1 |
| (Ord a, Ord b) => Ord (Either a b) | Since: base-2.1 |
| (Hashable a, Hashable b) => Hashable (Either a b) | |
Defined in Data.Hashable.Class | |
| (ToExpr a, ToExpr b) => ToExpr (Either a b) Source # | |
| (Serialise a, Serialise b) => Serialise (Either a b) | Since: serialise-0.2.0.0 |
| (FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (Product f g) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> Product f g a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> Product f g a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> Product f g a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> Product f g a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> Product f g a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> Product f g a -> b # | |
| (FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (Sum f g) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> Sum f g a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> Sum f g a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> Sum f g a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> Sum f g a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> Sum f g a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> Sum f g a -> b # | |
| (FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (f :*: g) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> (f :*: g) a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> (f :*: g) a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> (f :*: g) a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> (f :*: g) a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> (f :*: g) a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> (f :*: g) a -> b # | |
| (FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (Either i j) (f :+: g) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => (Either i j -> a -> m) -> (f :+: g) a -> m # ifoldMap' :: Monoid m => (Either i j -> a -> m) -> (f :+: g) a -> m # ifoldr :: (Either i j -> a -> b -> b) -> b -> (f :+: g) a -> b # ifoldl :: (Either i j -> b -> a -> b) -> b -> (f :+: g) a -> b # ifoldr' :: (Either i j -> a -> b -> b) -> b -> (f :+: g) a -> b # ifoldl' :: (Either i j -> b -> a -> b) -> b -> (f :+: g) a -> b # | |
| (FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (Product f g) | |
| (FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (Sum f g) | |
| (FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (f :*: g) | |
| (FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (Either i j) (f :+: g) | |
| (TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (Product f g) | |
| (TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (Sum f g) | |
| (TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (f :*: g) | |
| (TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (Either i j) (f :+: g) | |
| (RepeatWithIndex i f, RepeatWithIndex j g) => RepeatWithIndex (Either i j) (Product f g) | |
Defined in Data.Semialign.Internal | |
| (SemialignWithIndex i f, SemialignWithIndex j g) => SemialignWithIndex (Either i j) (Product f g) | |
Defined in Data.Semialign.Internal | |
| (ZipWithIndex i f, ZipWithIndex j g) => ZipWithIndex (Either i j) (Product f g) | |
| type Rep1 (Either a :: Type -> Type) | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep1 (Either a :: Type -> Type) = D1 ('MetaData "Either" "Data.Either" "base" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1)) | |
| type Failure (Either a) | |
Defined in Basement.Monad | |
| type StM (Either e) a | |
Defined in Control.Monad.Trans.Control | |
| type Rep (Either a b) | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep (Either a b) = D1 ('MetaData "Either" "Data.Either" "base" 'False) (C1 ('MetaCons "Left" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)) :+: C1 ('MetaCons "Right" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 b))) | |
Non-empty (and non-strict) list type.
Since: base-4.9.0.0
Constructors
| a :| [a] infixr 5 |
Instances
| FromJSON1 NonEmpty | |
| ToJSON1 NonEmpty | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> NonEmpty a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [NonEmpty a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> NonEmpty a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [NonEmpty a] -> Encoding # | |
| MonadFix NonEmpty | Since: base-4.9.0.0 |
Defined in Control.Monad.Fix | |
| Foldable NonEmpty | Since: base-4.9.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => NonEmpty m -> m # foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m # foldMap' :: Monoid m => (a -> m) -> NonEmpty a -> m # foldr :: (a -> b -> b) -> b -> NonEmpty a -> b # foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b # foldl :: (b -> a -> b) -> b -> NonEmpty a -> b # foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b # foldr1 :: (a -> a -> a) -> NonEmpty a -> a # foldl1 :: (a -> a -> a) -> NonEmpty a -> a # elem :: Eq a => a -> NonEmpty a -> Bool # maximum :: Ord a => NonEmpty a -> a # minimum :: Ord a => NonEmpty a -> a # | |
| Eq1 NonEmpty | Since: base-4.10.0.0 |
| Ord1 NonEmpty | Since: base-4.10.0.0 |
Defined in Data.Functor.Classes | |
| Read1 NonEmpty | Since: base-4.10.0.0 |
Defined in Data.Functor.Classes | |
| Show1 NonEmpty | Since: base-4.10.0.0 |
| Traversable NonEmpty | Since: base-4.9.0.0 |
| Applicative NonEmpty | Since: base-4.9.0.0 |
| Functor NonEmpty | Since: base-4.9.0.0 |
| Monad NonEmpty | Since: base-4.9.0.0 |
| Comonad NonEmpty | |
| ComonadApply NonEmpty | |
| NFData1 NonEmpty | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable1 NonEmpty | Since: hashable-1.3.1.0 |
Defined in Data.Hashable.Class | |
| Repeat NonEmpty | |
Defined in Data.Semialign.Internal | |
| Semialign NonEmpty | |
| Unzip NonEmpty | |
| Zip NonEmpty | |
| Generic1 NonEmpty | |
| Foldable1WithIndex Int NonEmpty | |
Defined in WithIndex Methods ifoldMap1 :: Semigroup m => (Int -> a -> m) -> NonEmpty a -> m # ifoldMap1' :: Semigroup m => (Int -> a -> m) -> NonEmpty a -> m # ifoldrMap1 :: (Int -> a -> b) -> (Int -> a -> b -> b) -> NonEmpty a -> b # ifoldlMap1' :: (Int -> a -> b) -> (Int -> b -> a -> b) -> NonEmpty a -> b # ifoldlMap1 :: (Int -> a -> b) -> (Int -> b -> a -> b) -> NonEmpty a -> b # ifoldrMap1' :: (Int -> a -> b) -> (Int -> a -> b -> b) -> NonEmpty a -> b # | |
| FoldableWithIndex Int NonEmpty | |
Defined in WithIndex | |
| FunctorWithIndex Int NonEmpty | |
| TraversableWithIndex Int NonEmpty | |
| RepeatWithIndex Int NonEmpty | |
Defined in Data.Semialign.Internal | |
| SemialignWithIndex Int NonEmpty | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Int NonEmpty | |
| Lift a => Lift (NonEmpty a :: Type) | Since: template-haskell-2.15.0.0 |
| FromJSON a => FromJSON (NonEmpty a) | |
| ToJSON a => ToJSON (NonEmpty a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (NonEmpty a) | Since: base-4.9.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> NonEmpty a -> c (NonEmpty a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (NonEmpty a) # toConstr :: NonEmpty a -> Constr # dataTypeOf :: NonEmpty a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (NonEmpty a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (NonEmpty a)) # gmapT :: (forall b. Data b => b -> b) -> NonEmpty a -> NonEmpty a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> NonEmpty a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> NonEmpty a -> r # gmapQ :: (forall d. Data d => d -> u) -> NonEmpty a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> NonEmpty a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> NonEmpty a -> m (NonEmpty a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> NonEmpty a -> m (NonEmpty a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> NonEmpty a -> m (NonEmpty a) # | |
| Semigroup (NonEmpty a) | Since: base-4.9.0.0 |
| IsList (NonEmpty a) | Since: base-4.9.0.0 |
| Generic (NonEmpty a) | |
| Read a => Read (NonEmpty a) | Since: base-4.11.0.0 |
| Show a => Show (NonEmpty a) | Since: base-4.11.0.0 |
| Binary a => Binary (NonEmpty a) | Since: binary-0.8.4.0 |
| NFData a => NFData (NonEmpty a) | Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (NonEmpty a) | Since: base-4.9.0.0 |
| Ord a => Ord (NonEmpty a) | Since: base-4.9.0.0 |
| Hashable a => Hashable (NonEmpty a) | |
Defined in Data.Hashable.Class | |
| ToExpr a => ToExpr (NonEmpty a) Source # | |
| Pretty a => Pretty (NonEmpty a) | |
Defined in Prettyprinter.Internal | |
| One (NonEmpty a) | Allows to create singleton
law> |
| Serialise a => Serialise (NonEmpty a) | Since: serialise-0.2.0.0 |
| type Rep1 NonEmpty | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep1 NonEmpty = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":|" ('InfixI 'LeftAssociative 9) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1 :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 []))) | |
| type Item (NonEmpty a) | |
| type Rep (NonEmpty a) | Since: base-4.6.0.0 |
Defined in GHC.Generics type Rep (NonEmpty a) = D1 ('MetaData "NonEmpty" "GHC.Base" "base" 'False) (C1 ('MetaCons ":|" ('InfixI 'LeftAssociative 9) 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a]))) | |
| type OneItem (NonEmpty a) | |
Defined in Relude.Container.One | |
data Constraint #
The kind of constraints, like Show a
class a ~R# b => Coercible (a :: k) (b :: k) #
Coercible is a two-parameter class that has instances for types a and b if
the compiler can infer that they have the same representation. This class
does not have regular instances; instead they are created on-the-fly during
type-checking. Trying to manually declare an instance of Coercible
is an error.
Nevertheless one can pretend that the following three kinds of instances exist. First, as a trivial base-case:
instance Coercible a a
Furthermore, for every type constructor there is
an instance that allows to coerce under the type constructor. For
example, let D be a prototypical type constructor (data or
newtype) with three type arguments, which have roles nominal,
representational resp. phantom. Then there is an instance of
the form
instance Coercible b b' => Coercible (D a b c) (D a b' c')
Note that the nominal type arguments are equal, the
representational type arguments can differ, but need to have a
Coercible instance themself, and the phantom type arguments can be
changed arbitrarily.
The third kind of instance exists for every newtype NT = MkNT T and
comes in two variants, namely
instance Coercible a T => Coercible a NT
instance Coercible T b => Coercible NT b
This instance is only usable if the constructor MkNT is in scope.
If, as a library author of a type constructor like Set a, you
want to prevent a user of your module to write
coerce :: Set T -> Set NT,
you need to set the role of Set's type parameter to nominal,
by writing
type role Set nominal
For more details about this feature, please refer to Safe Coercions by Joachim Breitner, Richard A. Eisenberg, Simon Peyton Jones and Stephanie Weirich.
Since: ghc-prim-4.7.0.0
CallStacks are a lightweight method of obtaining a
partial call-stack at any point in the program.
A function can request its call-site with the HasCallStack constraint.
For example, we can define
putStrLnWithCallStack :: HasCallStack => String -> IO ()
as a variant of putStrLn that will get its call-site and print it,
along with the string given as argument. We can access the
call-stack inside putStrLnWithCallStack with callStack.
>>>:{putStrLnWithCallStack :: HasCallStack => String -> IO () putStrLnWithCallStack msg = do putStrLn msg putStrLn (prettyCallStack callStack) :}
Thus, if we call putStrLnWithCallStack we will get a formatted call-stack
alongside our string.
>>>putStrLnWithCallStack "hello"hello CallStack (from HasCallStack): putStrLnWithCallStack, called at <interactive>:... in interactive:Ghci...
GHC solves HasCallStack constraints in three steps:
- If there is a
CallStackin scope -- i.e. the enclosing function has aHasCallStackconstraint -- GHC will append the new call-site to the existingCallStack. - If there is no
CallStackin scope -- e.g. in the GHCi session above -- and the enclosing definition does not have an explicit type signature, GHC will infer aHasCallStackconstraint for the enclosing definition (subject to the monomorphism restriction). - If there is no
CallStackin scope and the enclosing definition has an explicit type signature, GHC will solve theHasCallStackconstraint for the singletonCallStackcontaining just the current call-site.
CallStacks do not interact with the RTS and do not require compilation
with -prof. On the other hand, as they are built up explicitly via the
HasCallStack constraints, they will generally not contain as much
information as the simulated call-stacks maintained by the RTS.
A CallStack is a [(String, SrcLoc)]. The String is the name of
function that was called, the SrcLoc is the call-site. The list is
ordered with the most recently called function at the head.
NOTE: The intrepid user may notice that HasCallStack is just an
alias for an implicit parameter ?callStack :: CallStack. This is an
implementation detail and should not be considered part of the
CallStack API, we may decide to change the implementation in the
future.
Since: base-4.8.1.0
type family CmpNat (a :: Natural) (b :: Natural) :: Ordering where ... #
Comparison of type-level naturals, as a function.
Since: base-4.7.0.0
class Eq a => Hashable a where #
The class of types that can be converted to a hash value.
Minimal implementation: hashWithSalt.
Note: the hash is not guaranteed to be stable across library versions, operating systems or architectures. For stable hashing use named hashes: SHA256, CRC32 etc.
If you are looking for Hashable instance in time package,
check time-compat
Minimal complete definition
Nothing
Methods
hashWithSalt :: Int -> a -> Int infixl 0 #
Return a hash value for the argument, using the given salt.
The general contract of hashWithSalt is:
- If two values are equal according to the
==method, then applying thehashWithSaltmethod on each of the two values must produce the same integer result if the same salt is used in each case. - It is not required that if two values are unequal
according to the
==method, then applying thehashWithSaltmethod on each of the two values must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal values may improve the performance of hashing-based data structures. - This method can be used to compute different hash values for
the same input by providing a different salt in each
application of the method. This implies that any instance
that defines
hashWithSaltmust make use of the salt in its implementation. hashWithSaltmay return negativeIntvalues.
Instances
(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #
An infix synonym for fmap.
The name of this operator is an allusion to $.
Note the similarities between their types:
($) :: (a -> b) -> a -> b (<$>) :: Functor f => (a -> b) -> f a -> f b
Whereas $ is function application, <$> is function
application lifted over a Functor.
Examples
Convert from a Maybe IntMaybe
Stringshow:
>>>show <$> NothingNothing>>>show <$> Just 3Just "3"
Convert from an Either Int IntEither IntString using show:
>>>show <$> Left 17Left 17>>>show <$> Right 17Right "17"
Double each element of a list:
>>>(*2) <$> [1,2,3][2,4,6]
Apply even to the second element of a pair:
>>>even <$> (2,2)(2,True)
const x is a unary function which evaluates to x for all inputs.
>>>const 42 "hello"42
>>>map (const 42) [0..3][42,42,42,42]
data ByteString #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A ByteString contains 8-bit bytes, or by using the operations from
Data.ByteString.Char8 it can be interpreted as containing 8-bit
characters.
Instances
A space efficient, packed, unboxed Unicode text type.
Instances
A Map from keys k to values a.
The Semigroup operation for Map is union, which prefers
values from the left operand. If m1 maps a key k to a value
a1, and m2 maps the same key to a different value a2, then
their union m1 <> m2 maps k to a1.
Instances
| Bifoldable Map | Since: containers-0.6.3.1 |
| Eq2 Map | Since: containers-0.5.9 |
| Ord2 Map | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| Show2 Map | Since: containers-0.5.9 |
| Hashable2 Map | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| FoldableWithIndex k (Map k) | |
| FunctorWithIndex k (Map k) | |
| TraversableWithIndex k (Map k) | |
| Ord k => SemialignWithIndex k (Map k) | |
Defined in Data.Semialign.Internal | |
| Ord k => ZipWithIndex k (Map k) | |
| (FromJSONKey k, Ord k) => FromJSON1 (Map k) | |
| ToJSONKey k => ToJSON1 (Map k) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Map k a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Map k a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Map k a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Map k a] -> Encoding # | |
| Foldable (Map k) | Folds in order of increasing key. |
Defined in Data.Map.Internal Methods fold :: Monoid m => Map k m -> m # foldMap :: Monoid m => (a -> m) -> Map k a -> m # foldMap' :: Monoid m => (a -> m) -> Map k a -> m # foldr :: (a -> b -> b) -> b -> Map k a -> b # foldr' :: (a -> b -> b) -> b -> Map k a -> b # foldl :: (b -> a -> b) -> b -> Map k a -> b # foldl' :: (b -> a -> b) -> b -> Map k a -> b # foldr1 :: (a -> a -> a) -> Map k a -> a # foldl1 :: (a -> a -> a) -> Map k a -> a # elem :: Eq a => a -> Map k a -> Bool # maximum :: Ord a => Map k a -> a # minimum :: Ord a => Map k a -> a # | |
| Eq k => Eq1 (Map k) | Since: containers-0.5.9 |
| Ord k => Ord1 (Map k) | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| (Ord k, Read k) => Read1 (Map k) | Since: containers-0.5.9 |
Defined in Data.Map.Internal | |
| Show k => Show1 (Map k) | Since: containers-0.5.9 |
| Traversable (Map k) | Traverses in order of increasing key. |
| Functor (Map k) | |
| Hashable k => Hashable1 (Map k) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Ord k => Align (Map k) | |
Defined in Data.Semialign.Internal | |
| Ord k => Semialign (Map k) | |
| Ord k => Unalign (Map k) | |
| Ord k => Unzip (Map k) | |
| Ord k => Zip (Map k) | |
| (FromJSONKey k, Ord k, FromJSON v) => FromJSON (Map k v) | |
| (ToJSON v, ToJSONKey k) => ToJSON (Map k v) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data k, Data a, Ord k) => Data (Map k a) | |
Defined in Data.Map.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Map k a -> c (Map k a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Map k a) # toConstr :: Map k a -> Constr # dataTypeOf :: Map k a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Map k a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Map k a)) # gmapT :: (forall b. Data b => b -> b) -> Map k a -> Map k a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Map k a -> r # gmapQ :: (forall d. Data d => d -> u) -> Map k a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Map k a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k a -> m (Map k a) # | |
| Ord k => Monoid (Map k v) | |
| Ord k => Semigroup (Map k v) | |
| Ord k => IsList (Map k v) | Since: containers-0.5.6.2 |
| (Ord k, Read k, Read e) => Read (Map k e) | |
| (Show k, Show a) => Show (Map k a) | |
| (Binary k, Binary e) => Binary (Map k e) | |
| (NFData k, NFData a) => NFData (Map k a) | |
Defined in Data.Map.Internal | |
| (Eq k, Eq a) => Eq (Map k a) | |
| (Ord k, Ord v) => Ord (Map k v) | |
| (Hashable k, Hashable v) => Hashable (Map k v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| One (Map k v) | Create singleton
law> |
| Ord k => DynamicMap (Map k v) | Since: relude-0.1.0 |
Defined in Relude.Extra.Map Methods insert :: Key (Map k v) -> Val (Map k v) -> Map k v -> Map k v # insertWith :: (Val (Map k v) -> Val (Map k v) -> Val (Map k v)) -> Key (Map k v) -> Val (Map k v) -> Map k v -> Map k v # delete :: Key (Map k v) -> Map k v -> Map k v # alter :: (Maybe (Val (Map k v)) -> Maybe (Val (Map k v))) -> Key (Map k v) -> Map k v -> Map k v # | |
| Ord k => StaticMap (Map k v) | Since: relude-0.1.0 |
| (Ord k, Serialise k, Serialise v) => Serialise (Map k v) | Since: serialise-0.2.0.0 |
| type Item (Map k v) | |
Defined in Data.Map.Internal | |
| type OneItem (Map k v) | |
Defined in Relude.Container.One | |
| type Key (Map k v) | |
Defined in Relude.Extra.Map | |
| type Val (Map k v) | |
Defined in Relude.Extra.Map | |
A map from keys to values. A map cannot contain duplicate keys; each key can map to at most one value.
Instances
| Bifoldable HashMap | Since: unordered-containers-0.2.11 |
| Eq2 HashMap | |
| Ord2 HashMap | |
Defined in Data.HashMap.Internal | |
| Show2 HashMap | |
| NFData2 HashMap | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashMap.Internal | |
| Hashable2 HashMap | |
Defined in Data.HashMap.Internal | |
| (Eq k, Hashable k) => SemialignWithIndex k (HashMap k) | |
Defined in Data.Semialign.Internal | |
| (Eq k, Hashable k) => ZipWithIndex k (HashMap k) | |
| (Lift k, Lift v) => Lift (HashMap k v :: Type) | Since: unordered-containers-0.2.17.0 |
| (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (HashMap k) | |
| ToJSONKey k => ToJSON1 (HashMap k) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> HashMap k a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [HashMap k a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> HashMap k a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [HashMap k a] -> Encoding # | |
| Foldable (HashMap k) | |
Defined in Data.HashMap.Internal Methods fold :: Monoid m => HashMap k m -> m # foldMap :: Monoid m => (a -> m) -> HashMap k a -> m # foldMap' :: Monoid m => (a -> m) -> HashMap k a -> m # foldr :: (a -> b -> b) -> b -> HashMap k a -> b # foldr' :: (a -> b -> b) -> b -> HashMap k a -> b # foldl :: (b -> a -> b) -> b -> HashMap k a -> b # foldl' :: (b -> a -> b) -> b -> HashMap k a -> b # foldr1 :: (a -> a -> a) -> HashMap k a -> a # foldl1 :: (a -> a -> a) -> HashMap k a -> a # toList :: HashMap k a -> [a] # length :: HashMap k a -> Int # elem :: Eq a => a -> HashMap k a -> Bool # maximum :: Ord a => HashMap k a -> a # minimum :: Ord a => HashMap k a -> a # | |
| Eq k => Eq1 (HashMap k) | |
| Ord k => Ord1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| (Eq k, Hashable k, Read k) => Read1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| Show k => Show1 (HashMap k) | |
| Traversable (HashMap k) | |
Defined in Data.HashMap.Internal | |
| Functor (HashMap k) | |
| NFData k => NFData1 (HashMap k) | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashMap.Internal | |
| Hashable k => Hashable1 (HashMap k) | |
Defined in Data.HashMap.Internal | |
| (Eq k, Hashable k) => Align (HashMap k) | |
Defined in Data.Semialign.Internal | |
| (Eq k, Hashable k) => Semialign (HashMap k) | |
| (Eq k, Hashable k) => Unalign (HashMap k) | |
| (Eq k, Hashable k) => Unzip (HashMap k) | |
| (Eq k, Hashable k) => Zip (HashMap k) | |
| (Convertible e t f m, FromValue a m (NValue t f m)) => FromValue (AttrSet a) m (Deeper (NValue' t f m (NValue t f m))) Source # | |
| (Convertible e t f m, ToValue a m (NValue t f m)) => ToValue (AttrSet a) m (Deeper (NValue' t f m (NValue t f m))) Source # | |
| Convertible e t f m => FromValue (AttrSet (NValue t f m)) m (NValue' t f m (NValue t f m)) Source # | |
| Convertible e t f m => ToValue (AttrSet (NValue t f m)) m (NValue' t f m (NValue t f m)) Source # | |
| (FromJSON v, FromJSONKey k, Eq k, Hashable k) => FromJSON (HashMap k v) | |
| (ToJSON v, ToJSONKey k) => ToJSON (HashMap k v) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data k, Data v, Eq k, Hashable k) => Data (HashMap k v) | |
Defined in Data.HashMap.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashMap k v -> c (HashMap k v) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashMap k v) # toConstr :: HashMap k v -> Constr # dataTypeOf :: HashMap k v -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashMap k v)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashMap k v)) # gmapT :: (forall b. Data b => b -> b) -> HashMap k v -> HashMap k v # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashMap k v -> r # gmapQ :: (forall d. Data d => d -> u) -> HashMap k v -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> HashMap k v -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashMap k v -> m (HashMap k v) # | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| (Eq k, Hashable k) => Semigroup (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| (Eq k, Hashable k) => IsList (HashMap k v) | |
| (Eq k, Hashable k, Read k, Read e) => Read (HashMap k e) | |
| (Show k, Show v) => Show (HashMap k v) | |
| (NFData k, NFData v) => NFData (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| (Eq k, Eq v) => Eq (HashMap k v) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| (Ord k, Ord v) => Ord (HashMap k v) | The ordering is total and consistent with the |
Defined in Data.HashMap.Internal | |
| (Hashable k, Hashable v) => Hashable (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| Hashable k => One (HashMap k v) | Create singleton
law> |
| Hashable k => DynamicMap (HashMap k v) | Since: relude-0.1.0 |
Defined in Relude.Extra.Map Methods insert :: Key (HashMap k v) -> Val (HashMap k v) -> HashMap k v -> HashMap k v # insertWith :: (Val (HashMap k v) -> Val (HashMap k v) -> Val (HashMap k v)) -> Key (HashMap k v) -> Val (HashMap k v) -> HashMap k v -> HashMap k v # delete :: Key (HashMap k v) -> HashMap k v -> HashMap k v # alter :: (Maybe (Val (HashMap k v)) -> Maybe (Val (HashMap k v))) -> Key (HashMap k v) -> HashMap k v -> HashMap k v # | |
| Hashable k => StaticMap (HashMap k v) | Since: relude-0.1.0 |
| (Serialise k, Hashable k, Eq k, Serialise v) => Serialise (HashMap k v) | Since: serialise-0.2.0.0 |
| FromValue (AttrSet (Symbolic m), PositionSet) m (Symbolic m) Source # | |
| (Convertible e t f m, FromValue a m (NValue t f m)) => FromValue (AttrSet a, PositionSet) m (Deeper (NValue' t f m (NValue t f m))) Source # | |
Defined in Nix.Convert | |
| ToValue (AttrSet (Symbolic m), PositionSet) m (Symbolic m) Source # | |
| (Convertible e t f m, ToValue a m (NValue t f m)) => ToValue (AttrSet a, PositionSet) m (Deeper (NValue' t f m (NValue t f m))) Source # | |
Defined in Nix.Convert | |
| Convertible e t f m => FromValue (AttrSet (NValue t f m), PositionSet) m (NValue' t f m (NValue t f m)) Source # | |
Defined in Nix.Convert | |
| Convertible e t f m => ToValue (AttrSet (NValue t f m), PositionSet) m (NValue' t f m (NValue t f m)) Source # | |
Defined in Nix.Convert | |
| Monad m => MonadState (HashMap Path NExprLoc, HashMap Text Text) (StandardTF r m) Source # | |
| type Item (HashMap k v) | |
Defined in Data.HashMap.Internal | |
| type OneItem (HashMap k v) | |
Defined in Relude.Container.One | |
| type Key (HashMap k v) | |
Defined in Relude.Extra.Map | |
| type Val (HashMap k v) | |
Defined in Relude.Extra.Map | |
(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c infixr 1 #
Left-to-right composition of Kleisli arrows.
'(bs ' can be understood as the >=> cs) ado expression
do b <- bs a cs b
partitionEithers :: [Either a b] -> ([a], [b]) #
Partitions a list of Either into two lists.
All the Left elements are extracted, in order, to the first
component of the output. Similarly the Right elements are extracted
to the second component of the output.
Examples
Basic usage:
>>>let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]>>>partitionEithers list(["foo","bar","baz"],[3,7])
The pair returned by partitionEithers x(:lefts x, rights x)
>>>let list = [ Left "foo", Right 3, Left "bar", Right 7, Left "baz" ]>>>partitionEithers list == (lefts list, rights list)True
class Applicative f => Alternative (f :: Type -> Type) where #
A monoid on applicative functors.
If defined, some and many should be the least solutions
of the equations:
Methods
The identity of <|>
(<|>) :: f a -> f a -> f a infixl 3 #
An associative binary operation
One or more.
Zero or more.
Instances
class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type) where #
Monads that also support choice and failure.
Minimal complete definition
Nothing
Methods
The identity of mplus. It should also satisfy the equations
mzero >>= f = mzero v >> mzero = mzero
The default definition is
mzero = empty
An associative operation. The default definition is
mplus = (<|>)
Instances
| MonadPlus IResult | |
| MonadPlus Parser | |
| MonadPlus Result | |
| MonadPlus Graph | |
| MonadPlus STM | Since: base-4.3.0.0 |
| MonadPlus P | Since: base-2.1 |
Defined in Text.ParserCombinators.ReadP | |
| MonadPlus ReadP | Since: base-2.1 |
| MonadPlus ReadPrec | Since: base-2.1 |
| MonadPlus Get | Since: binary-0.7.1.0 |
| MonadPlus Seq | |
| MonadPlus DList | |
| MonadPlus IO | Since: base-4.9.0.0 |
| MonadPlus ReadM | |
| MonadPlus Array | |
| MonadPlus SmallArray | |
Defined in Data.Primitive.SmallArray | |
| MonadPlus Vector | |
| MonadPlus Maybe | Since: base-2.1 |
| MonadPlus [] | Since: base-2.1 |
| MonadPlus (Parser i) | |
| (ArrowApply a, ArrowPlus a) => MonadPlus (ArrowMonad a) | Since: base-4.6.0.0 |
Defined in Control.Arrow | |
| MonadPlus (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| MonadPlus (U1 :: Type -> Type) | Since: base-4.9.0.0 |
| (Functor v, MonadPlus v) => MonadPlus (Free v) | This violates the MonadPlus laws, handle with care. |
| MonadPlus (LogicT m) | |
| Monad m => MonadPlus (ListT m) | |
| Monad m => MonadPlus (MaybeT m) | |
| MonadPlus m => MonadPlus (Kleisli m a) | Since: base-4.14.0.0 |
| MonadPlus f => MonadPlus (Ap f) | Since: base-4.12.0.0 |
| MonadPlus f => MonadPlus (Alt f) | Since: base-4.8.0.0 |
| MonadPlus f => MonadPlus (Rec1 f) | Since: base-4.9.0.0 |
| (Functor f, MonadPlus m) => MonadPlus (FreeT f m) | |
| MonadPlus m => MonadPlus (FreshIdT i m) Source # | |
| MonadPlus m => MonadPlus (StandardTF r m) Source # | |
Defined in Nix.Standard Methods mzero :: StandardTF r m a # mplus :: StandardTF r m a -> StandardTF r m a -> StandardTF r m a # | |
| MonadPlus (t (Fix1 t)) => MonadPlus (Fix1 t) Source # | |
| (Monoid w, Functor m, MonadPlus m) => MonadPlus (AccumT w m) | |
| (Monad m, Error e) => MonadPlus (ErrorT e m) | |
| (Monad m, Monoid e) => MonadPlus (ExceptT e m) | |
| MonadPlus m => MonadPlus (IdentityT m) | |
| MonadPlus m => MonadPlus (ReaderT r m) | |
| MonadPlus m => MonadPlus (SelectT r m) | |
| MonadPlus m => MonadPlus (StateT s m) | |
| MonadPlus m => MonadPlus (StateT s m) | |
| (Functor m, MonadPlus m) => MonadPlus (WriterT w m) | |
| (Monoid w, MonadPlus m) => MonadPlus (WriterT w m) | |
| (Monoid w, MonadPlus m) => MonadPlus (WriterT w m) | |
| (MonadPlus f, MonadPlus g) => MonadPlus (Product f g) | Since: base-4.9.0.0 |
| (MonadPlus f, MonadPlus g) => MonadPlus (f :*: g) | Since: base-4.9.0.0 |
| MonadPlus (t (Fix1T t m) m) => MonadPlus (Fix1T t m) Source # | |
| (Ord e, Stream s) => MonadPlus (ParsecT e s m) |
Note: strictly speaking, this instance is unlawful. The right identity law does not hold, e.g. in general this is not true: v >> mzero = mero However the following holds: try v >> mzero = mzero |
| MonadPlus f => MonadPlus (M1 i c f) | Since: base-4.9.0.0 |
| (Functor m, MonadPlus m) => MonadPlus (RWST r w s m) | |
| (Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) | |
| (Monoid w, MonadPlus m) => MonadPlus (RWST r w s m) | |
isRight :: Either a b -> Bool #
Return True if the given value is a Right-value, False otherwise.
Examples
Basic usage:
>>>isRight (Left "foo")False>>>isRight (Right 3)True
Assuming a Left value signifies some sort of error, we can use
isRight to write a very simple reporting function that only
outputs "SUCCESS" when a computation has succeeded.
This example shows how isRight might be used to avoid pattern
matching when one does not care about the value contained in the
constructor:
>>>import Control.Monad ( when )>>>let report e = when (isRight e) $ putStrLn "SUCCESS">>>report (Left "parse error")>>>report (Right 1)SUCCESS
Since: base-4.7.0.0
flip :: (a -> b -> c) -> b -> a -> c #
flip ff.
>>>flip (++) "hello" "world""worldhello"
The transpose function transposes the rows and columns of its argument.
For example,
>>>transpose [[1,2,3],[4,5,6]][[1,4],[2,5],[3,6]]
If some of the rows are shorter than the following rows, their elements are skipped:
>>>transpose [[10,11],[20],[],[30,31,32]][[10,20,30],[11,31],[32]]
concat :: Foldable t => t [a] -> [a] #
The concatenation of all the elements of a container of lists.
Examples
Basic usage:
>>>concat (Just [1, 2, 3])[1,2,3]
>>>concat (Left 42)[]
>>>concat [[1, 2, 3], [4, 5], [6], []][1,2,3,4,5,6]
reverse xs returns the elements of xs in reverse order.
xs must be finite.
>>>reverse [][]>>>reverse [42][42]>>>reverse [2,5,7][7,5,2]>>>reverse [1..]* Hangs forever *
all :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether all elements of the structure satisfy the predicate.
Examples
Basic usage:
>>>all (> 3) []True
>>>all (> 3) [1,2]False
>>>all (> 3) [1,2,3,4,5]False
>>>all (> 3) [1..]False
>>>all (> 3) [4..]* Hangs forever *
uncurry :: (a -> b -> c) -> (a, b) -> c #
uncurry converts a curried function to a function on pairs.
Examples
>>>uncurry (+) (1,2)3
>>>uncurry ($) (show, 1)"1"
>>>map (uncurry max) [(1,2), (3,4), (6,8)][2,4,8]
(<**>) :: Applicative f => f a -> f (a -> b) -> f b infixl 4 #
A variant of <*> with the arguments reversed.
Haskell defines operations to read and write characters from and to files,
represented by values of type Handle. Each value of this type is a
handle: a record used by the Haskell run-time system to manage I/O
with file system objects. A handle has at least the following properties:
- whether it manages input or output or both;
- whether it is open, closed or semi-closed;
- whether the object is seekable;
- whether buffering is disabled, or enabled on a line or block basis;
- a buffer (whose length may be zero).
Most handles will also have a current I/O position indicating where the next
input or output operation will occur. A handle is readable if it
manages only input or both input and output; likewise, it is writable if
it manages only output or both input and output. A handle is open when
first allocated.
Once it is closed it can no longer be used for either input or output,
though an implementation cannot re-use its storage while references
remain to it. Handles are in the Show and Eq classes. The string
produced by showing a handle is system dependent; it should include
enough information to identify the handle for debugging. A handle is
equal according to == only to itself; no attempt
is made to compare the internal state of different handles for equality.
Instances
class Bifunctor (p :: Type -> Type -> Type) where #
A bifunctor is a type constructor that takes
two type arguments and is a functor in both arguments. That
is, unlike with Functor, a type constructor such as Either
does not need to be partially applied for a Bifunctor
instance, and the methods in this class permit mapping
functions over the Left value or the Right value,
or both at the same time.
Formally, the class Bifunctor represents a bifunctor
from Hask -> Hask.
Intuitively it is a bifunctor where both the first and second arguments are covariant.
You can define a Bifunctor by either defining bimap or by
defining both first and second.
If you supply bimap, you should ensure that:
bimapidid≡id
If you supply first and second, ensure:
firstid≡idsecondid≡id
If you supply both, you should also ensure:
bimapf g ≡firstf.secondg
These ensure by parametricity:
bimap(f.g) (h.i) ≡bimapf h.bimapg ifirst(f.g) ≡firstf.firstgsecond(f.g) ≡secondf.secondg
Since: base-4.8.0.0
Methods
bimap :: (a -> b) -> (c -> d) -> p a c -> p b d #
Map over both arguments at the same time.
bimapf g ≡firstf.secondg
Examples
>>>bimap toUpper (+1) ('j', 3)('J',4)
>>>bimap toUpper (+1) (Left 'j')Left 'J'
>>>bimap toUpper (+1) (Right 3)Right 4
Instances
Constructors
| Predicate | |
Fields
| |
Instances
| Contravariant Predicate | A Without newtypes contramap :: (a' -> a) -> (Predicate a -> Predicate a') contramap f (Predicate g) = Predicate (g . f) |
| Monoid (Predicate a) |
mempty :: Predicate a mempty = _ -> True |
| Semigroup (Predicate a) |
(<>) :: Predicate a -> Predicate a -> Predicate a Predicate pred <> Predicate pred' = Predicate a -> pred a && pred' a |
Dual function arrows.
Instances
| Category Op | |
| Contravariant (Op a) | |
| Monoid a => Monoid (Op a b) |
mempty :: Op a b mempty = Op _ -> mempty |
| Semigroup a => Semigroup (Op a b) |
(<>) :: Op a b -> Op a b -> Op a b Op f <> Op g = Op a -> f a <> g a |
| Floating a => Floating (Op a b) | |
| Num a => Num (Op a b) | |
| Fractional a => Fractional (Op a b) | |
newtype Equivalence a #
This data type represents an equivalence relation.
Equivalence relations are expected to satisfy three laws:
- Reflexivity
getEquivalencef a a = True- Symmetry
getEquivalencef a b =getEquivalencef b a- Transitivity
- If
getEquivalencef a bgetEquivalencef b cTruethen so isgetEquivalencef a c
The types alone do not enforce these laws, so you'll have to check them yourself.
Constructors
| Equivalence | |
Fields
| |
Instances
| Contravariant Equivalence | Equivalence relations are |
Defined in Data.Functor.Contravariant Methods contramap :: (a' -> a) -> Equivalence a -> Equivalence a' # (>$) :: b -> Equivalence b -> Equivalence a # | |
| Monoid (Equivalence a) |
mempty :: Equivalence a mempty = Equivalence _ _ -> True |
Defined in Data.Functor.Contravariant Methods mempty :: Equivalence a # mappend :: Equivalence a -> Equivalence a -> Equivalence a # mconcat :: [Equivalence a] -> Equivalence a # | |
| Semigroup (Equivalence a) |
(<>) :: Equivalence a -> Equivalence a -> Equivalence a Equivalence equiv <> Equivalence equiv' = Equivalence a b -> equiv a b && equiv a b |
Defined in Data.Functor.Contravariant Methods (<>) :: Equivalence a -> Equivalence a -> Equivalence a # sconcat :: NonEmpty (Equivalence a) -> Equivalence a # stimes :: Integral b => b -> Equivalence a -> Equivalence a # | |
class Contravariant (f :: Type -> Type) where #
The class of contravariant functors.
Whereas in Haskell, one can think of a Functor as containing or producing
values, a contravariant functor is a functor that can be thought of as
consuming values.
As an example, consider the type of predicate functions a -> Bool. One
such predicate might be negative x = x < 0, which
classifies integers as to whether they are negative. However, given this
predicate, we can re-use it in other situations, providing we have a way to
map values to integers. For instance, we can use the negative predicate
on a person's bank balance to work out if they are currently overdrawn:
newtype Predicate a = Predicate { getPredicate :: a -> Bool }
instance Contravariant Predicate where
contramap :: (a' -> a) -> (Predicate a -> Predicate a')
contramap f (Predicate p) = Predicate (p . f)
| `- First, map the input...
`----- then apply the predicate.
overdrawn :: Predicate Person
overdrawn = contramap personBankBalance negative
Any instance should be subject to the following laws:
Note, that the second law follows from the free theorem of the type of
contramap and the first law, so you need only check that the former
condition holds.
Minimal complete definition
Instances
newtype Comparison a #
Defines a total ordering on a type as per compare.
This condition is not checked by the types. You must ensure that the supplied values are valid total orderings yourself.
Constructors
| Comparison | |
Fields
| |
Instances
| Contravariant Comparison | A |
Defined in Data.Functor.Contravariant Methods contramap :: (a' -> a) -> Comparison a -> Comparison a' # (>$) :: b -> Comparison b -> Comparison a # | |
| Monoid (Comparison a) |
mempty :: Comparison a mempty = Comparison _ _ -> EQ |
Defined in Data.Functor.Contravariant Methods mempty :: Comparison a # mappend :: Comparison a -> Comparison a -> Comparison a # mconcat :: [Comparison a] -> Comparison a # | |
| Semigroup (Comparison a) |
(<>) :: Comparison a -> Comparison a -> Comparison a Comparison cmp <> Comparison cmp' = Comparison a a' -> cmp a a' <> cmp a a' |
Defined in Data.Functor.Contravariant Methods (<>) :: Comparison a -> Comparison a -> Comparison a # sconcat :: NonEmpty (Comparison a) -> Comparison a # stimes :: Integral b => b -> Comparison a -> Comparison a # | |
phantom :: (Functor f, Contravariant f) => f a -> f b #
If f is both Functor and Contravariant then by the time you factor
in the laws of each of those classes, it can't actually use its argument in
any meaningful capacity.
This method is surprisingly useful. Where both instances exist and are lawful we have the following laws:
fmapf ≡phantomcontramapf ≡phantom
defaultEquivalence :: Eq a => Equivalence a #
defaultComparison :: Ord a => Comparison a #
Compare using compare.
comparisonEquivalence :: Comparison a -> Equivalence a #
(>$<) :: Contravariant f => (a -> b) -> f b -> f a infixl 4 #
This is an infix alias for contramap.
(>$$<) :: Contravariant f => f b -> (a -> b) -> f a infixl 4 #
This is an infix version of contramap with the arguments flipped.
($<) :: Contravariant f => f b -> b -> f a infixl 4 #
This is >$ with its arguments flipped.
newtype Compose (f :: k -> Type) (g :: k1 -> k) (a :: k1) infixr 9 #
Right-to-left composition of functors. The composition of applicative functors is always applicative, but the composition of monads is not always a monad.
Constructors
| Compose infixr 9 | |
Fields
| |
Instances
| Binary NExprLoc Source # | |
| Serialise NExprLoc Source # | |
| TestEquality f => TestEquality (Compose f g :: k2 -> Type) | The deduction (via generativity) that if Since: base-4.14.0.0 |
Defined in Data.Functor.Compose | |
| Functor f => Generic1 (Compose f g :: k -> Type) | |
| Unbox (f (g a)) => Vector Vector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Compose f g a) -> ST s (Vector (Compose f g a)) # basicUnsafeThaw :: Vector (Compose f g a) -> ST s (Mutable Vector s (Compose f g a)) # basicLength :: Vector (Compose f g a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Compose f g a) -> Vector (Compose f g a) # basicUnsafeIndexM :: Vector (Compose f g a) -> Int -> Box (Compose f g a) # basicUnsafeCopy :: Mutable Vector s (Compose f g a) -> Vector (Compose f g a) -> ST s () # elemseq :: Vector (Compose f g a) -> Compose f g a -> b -> b # | |
| Unbox (f (g a)) => MVector MVector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Compose f g a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Compose f g a) -> MVector s (Compose f g a) # basicOverlaps :: MVector s (Compose f g a) -> MVector s (Compose f g a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Compose f g a)) # basicInitialize :: MVector s (Compose f g a) -> ST s () # basicUnsafeReplicate :: Int -> Compose f g a -> ST s (MVector s (Compose f g a)) # basicUnsafeRead :: MVector s (Compose f g a) -> Int -> ST s (Compose f g a) # basicUnsafeWrite :: MVector s (Compose f g a) -> Int -> Compose f g a -> ST s () # basicClear :: MVector s (Compose f g a) -> ST s () # basicSet :: MVector s (Compose f g a) -> Compose f g a -> ST s () # basicUnsafeCopy :: MVector s (Compose f g a) -> MVector s (Compose f g a) -> ST s () # basicUnsafeMove :: MVector s (Compose f g a) -> MVector s (Compose f g a) -> ST s () # basicUnsafeGrow :: MVector s (Compose f g a) -> Int -> ST s (MVector s (Compose f g a)) # | |
| Binary r => Binary (NExprLocF r) Source # | |
| Serialise r => Serialise (NExprLocF r) Source # | |
| Monad m => MonadState (HashMap Path NExprLoc, HashMap Text Text) (StandardTF r m) Source # | |
| (FoldableWithIndex i f, FoldableWithIndex j g) => FoldableWithIndex (i, j) (Compose f g) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => ((i, j) -> a -> m) -> Compose f g a -> m # ifoldMap' :: Monoid m => ((i, j) -> a -> m) -> Compose f g a -> m # ifoldr :: ((i, j) -> a -> b -> b) -> b -> Compose f g a -> b # ifoldl :: ((i, j) -> b -> a -> b) -> b -> Compose f g a -> b # ifoldr' :: ((i, j) -> a -> b -> b) -> b -> Compose f g a -> b # ifoldl' :: ((i, j) -> b -> a -> b) -> b -> Compose f g a -> b # | |
| (FunctorWithIndex i f, FunctorWithIndex j g) => FunctorWithIndex (i, j) (Compose f g) | |
| (TraversableWithIndex i f, TraversableWithIndex j g) => TraversableWithIndex (i, j) (Compose f g) | |
| (RepeatWithIndex i f, RepeatWithIndex j g) => RepeatWithIndex (i, j) (Compose f g) | |
Defined in Data.Semialign.Internal | |
| (SemialignWithIndex i f, SemialignWithIndex j g) => SemialignWithIndex (i, j) (Compose f g) | |
Defined in Data.Semialign.Internal | |
| (ZipWithIndex i f, ZipWithIndex j g) => ZipWithIndex (i, j) (Compose f g) | |
| (FromJSON1 f, FromJSON1 g) => FromJSON1 (Compose f g) | |
| (ToJSON1 f, ToJSON1 g) => ToJSON1 (Compose f g) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Compose f g a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Compose f g a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Compose f g a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Compose f g a] -> Encoding # | |
| (Foldable f, Foldable g) => Foldable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods fold :: Monoid m => Compose f g m -> m # foldMap :: Monoid m => (a -> m) -> Compose f g a -> m # foldMap' :: Monoid m => (a -> m) -> Compose f g a -> m # foldr :: (a -> b -> b) -> b -> Compose f g a -> b # foldr' :: (a -> b -> b) -> b -> Compose f g a -> b # foldl :: (b -> a -> b) -> b -> Compose f g a -> b # foldl' :: (b -> a -> b) -> b -> Compose f g a -> b # foldr1 :: (a -> a -> a) -> Compose f g a -> a # foldl1 :: (a -> a -> a) -> Compose f g a -> a # toList :: Compose f g a -> [a] # null :: Compose f g a -> Bool # length :: Compose f g a -> Int # elem :: Eq a => a -> Compose f g a -> Bool # maximum :: Ord a => Compose f g a -> a # minimum :: Ord a => Compose f g a -> a # | |
| (Eq1 f, Eq1 g) => Eq1 (Compose f g) | Since: base-4.9.0.0 |
| (Ord1 f, Ord1 g) => Ord1 (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Read1 f, Read1 g) => Read1 (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Compose f g a) # liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Compose f g a] # liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Compose f g a) # liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Compose f g a] # | |
| (Show1 f, Show1 g) => Show1 (Compose f g) | Since: base-4.9.0.0 |
| (Functor f, Contravariant g) => Contravariant (Compose f g) | |
| (Traversable f, Traversable g) => Traversable (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Alternative f, Applicative g) => Alternative (Compose f g) | Since: base-4.9.0.0 |
| (Applicative f, Applicative g) => Applicative (Compose f g) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| (Functor f, Functor g) => Functor (Compose f g) | Since: base-4.9.0.0 |
| (NFData1 f, NFData1 g) => NFData1 (Compose f g) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| (Hashable1 f, Hashable1 g) => Hashable1 (Compose f g) | |
Defined in Data.Hashable.Class | |
| (Identical f, Identical g) => Identical (Compose f g) | |
Defined in Lens.Family.Identical | |
| (Phantom f, Functor g) => Phantom (Compose f g) | |
Defined in Lens.Family.Phantom | |
| (Align f, Semialign g) => Align (Compose f g) | |
Defined in Data.Semialign.Internal | |
| (Repeat f, Repeat g) => Repeat (Compose f g) | |
Defined in Data.Semialign.Internal | |
| (Semialign f, Semialign g) => Semialign (Compose f g) | |
| (Unzip f, Unzip g) => Unzip (Compose f g) | |
| (Zip f, Zip g) => Zip (Compose f g) | |
| (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Compose f g a) | |
| (ToJSON1 f, ToJSON1 g, ToJSON a) => ToJSON (Compose f g a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Typeable a, Typeable f, Typeable g, Typeable k1, Typeable k2, Data (f (g a))) => Data (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g0. g0 -> c g0) -> Compose f g a -> c (Compose f g a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Compose f g a) # toConstr :: Compose f g a -> Constr # dataTypeOf :: Compose f g a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Compose f g a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Compose f g a)) # gmapT :: (forall b. Data b => b -> b) -> Compose f g a -> Compose f g a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Compose f g a -> r # gmapQ :: (forall d. Data d => d -> u) -> Compose f g a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Compose f g a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Compose f g a -> m (Compose f g a) # | |
| Monoid (f (g a)) => Monoid (Compose f g a) | Since: base-4.16.0.0 |
| Semigroup (f (g a)) => Semigroup (Compose f g a) | Since: base-4.16.0.0 |
| Generic (Compose f g a) | |
| (Read1 f, Read1 g, Read a) => Read (Compose f g a) | Since: base-4.9.0.0 |
| (Show1 f, Show1 g, Show a) => Show (Compose f g a) | Since: base-4.9.0.0 |
| (NFData1 f, NFData1 g, NFData a) => NFData (Compose f g a) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| (Eq1 f, Eq1 g, Eq a) => Eq (Compose f g a) | Since: base-4.9.0.0 |
| (Ord1 f, Ord1 g, Ord a) => Ord (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose Methods compare :: Compose f g a -> Compose f g a -> Ordering # (<) :: Compose f g a -> Compose f g a -> Bool # (<=) :: Compose f g a -> Compose f g a -> Bool # (>) :: Compose f g a -> Compose f g a -> Bool # (>=) :: Compose f g a -> Compose f g a -> Bool # | |
| (Hashable1 f, Hashable1 g, Hashable a) => Hashable (Compose f g a) | In general, |
Defined in Data.Hashable.Class | |
| Unbox (f (g a)) => Unbox (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Compose f g :: k -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| newtype MVector s (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Compose f g a) | Since: base-4.9.0.0 |
Defined in Data.Functor.Compose | |
| newtype Vector (Compose f g a) | |
Defined in Data.Vector.Unboxed.Base | |
Uninhabited data type
Since: base-4.8.0.0
Instances
| FromJSON Void | |
| FromJSONKey Void | Since: aeson-2.1.2.0 |
Defined in Data.Aeson.Types.FromJSON | |
| ToJSON Void | |
Defined in Data.Aeson.Types.ToJSON | |
| ToJSONKey Void | Since: aeson-2.1.2.0 |
Defined in Data.Aeson.Types.ToJSON | |
| Data Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Void -> c Void # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Void # dataTypeOf :: Void -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Void) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Void) # gmapT :: (forall b. Data b => b -> b) -> Void -> Void # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQ :: (forall d. Data d => d -> u) -> Void -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Void -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # | |
| Semigroup Void | Since: base-4.9.0.0 |
| Exception Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String # | |
| Generic Void | |
| Ix Void | Since: base-4.8.0.0 |
| Read Void | Reading a Since: base-4.8.0.0 |
| Show Void | Since: base-4.8.0.0 |
| Binary Void | Since: binary-0.8.0.0 |
| NFData Void | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq Void | Since: base-4.8.0.0 |
| Ord Void | Since: base-4.8.0.0 |
| Hashable Void | |
Defined in Data.Hashable.Class | |
| ShowErrorComponent Void | |
Defined in Text.Megaparsec.Error | |
| Pretty Void | Finding a good example for printing something that does not exist is hard, so here is an example of printing a list full of nothing.
|
Defined in Prettyprinter.Internal | |
| Serialise Void | Since: serialise-0.2.4.0 |
| Lift Void | Since: template-haskell-2.15.0.0 |
| FoldableWithIndex Void (Proxy :: Type -> Type) | |
Defined in WithIndex | |
| FoldableWithIndex Void (U1 :: Type -> Type) | |
| FoldableWithIndex Void (V1 :: Type -> Type) | |
| FunctorWithIndex Void (Proxy :: Type -> Type) | |
| FunctorWithIndex Void (U1 :: Type -> Type) | |
| FunctorWithIndex Void (V1 :: Type -> Type) | |
| TraversableWithIndex Void (Proxy :: Type -> Type) | |
| TraversableWithIndex Void (U1 :: Type -> Type) | |
| TraversableWithIndex Void (V1 :: Type -> Type) | |
| RepeatWithIndex Void (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| SemialignWithIndex Void (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Void (Proxy :: Type -> Type) | |
| FoldableWithIndex Void (Const e :: Type -> Type) | |
Defined in WithIndex | |
| FoldableWithIndex Void (Constant e :: Type -> Type) | |
Defined in WithIndex Methods ifoldMap :: Monoid m => (Void -> a -> m) -> Constant e a -> m # ifoldMap' :: Monoid m => (Void -> a -> m) -> Constant e a -> m # ifoldr :: (Void -> a -> b -> b) -> b -> Constant e a -> b # ifoldl :: (Void -> b -> a -> b) -> b -> Constant e a -> b # ifoldr' :: (Void -> a -> b -> b) -> b -> Constant e a -> b # ifoldl' :: (Void -> b -> a -> b) -> b -> Constant e a -> b # | |
| FunctorWithIndex Void (Const e :: Type -> Type) | |
| FunctorWithIndex Void (Constant e :: Type -> Type) | |
| TraversableWithIndex Void (Const e :: Type -> Type) | |
| TraversableWithIndex Void (Constant e :: Type -> Type) | |
| FoldableWithIndex Void (K1 i c :: Type -> Type) | |
Defined in WithIndex | |
| FunctorWithIndex Void (K1 i c :: Type -> Type) | |
| TraversableWithIndex Void (K1 i c :: Type -> Type) | |
| type Rep Void | Since: base-4.8.0.0 |
Since Void values logically don't exist, this witnesses the
logical reasoning tool of "ex falso quodlibet".
>>>let x :: Either Void Int; x = Right 5>>>:{case x of Right r -> r Left l -> absurd l :} 5
Since: base-4.8.0.0
data WrappedMonoid m #
Provide a Semigroup for an arbitrary Monoid.
NOTE: This is not needed anymore since Semigroup became a superclass of
Monoid in base-4.11 and this newtype be deprecated at some point in the future.
Instances
mtimesDefault :: (Integral b, Monoid a) => b -> a -> a #
sortWith :: Ord b => (a -> b) -> [a] -> [a] #
The sortWith function sorts a list of elements using the
user supplied function to project something out of each element
class (Bifunctor t, Bifoldable t) => Bitraversable (t :: Type -> Type -> Type) where #
Bitraversable identifies bifunctorial data structures whose elements can
be traversed in order, performing Applicative or Monad actions at each
element, and collecting a result structure with the same shape.
As opposed to Traversable data structures, which have one variety of
element on which an action can be performed, Bitraversable data structures
have two such varieties of elements.
A definition of bitraverse must satisfy the following laws:
- Naturality
bitraverse(t . f) (t . g) ≡ t .bitraversef gt- Identity
bitraverseIdentityIdentity≡Identity- Composition
Compose.fmap(bitraverseg1 g2) .bitraversef1 f2 ≡bitraverse(Compose.fmapg1 . f1) (Compose.fmapg2 . f2)
where an applicative transformation is a function
t :: (Applicativef,Applicativeg) => f a -> g a
preserving the Applicative operations:
t (purex) =purex t (f<*>x) = t f<*>t x
and the identity functor Identity and composition functors
Compose are from Data.Functor.Identity and
Data.Functor.Compose.
Some simple examples are Either and (,):
instance Bitraversable Either where bitraverse f _ (Left x) = Left <$> f x bitraverse _ g (Right y) = Right <$> g y instance Bitraversable (,) where bitraverse f g (x, y) = (,) <$> f x <*> g y
Bitraversable relates to its superclasses in the following ways:
bimapf g ≡runIdentity.bitraverse(Identity. f) (Identity. g)bifoldMapf g =getConst.bitraverse(Const. f) (Const. g)
These are available as bimapDefault and bifoldMapDefault respectively.
Since: base-4.10.0.0
Minimal complete definition
Nothing
Methods
bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> t a b -> f (t c d) #
Evaluates the relevant functions at each element in the structure, running the action, and builds a new structure with the same shape, using the results produced from sequencing the actions.
bitraversef g ≡bisequenceA.bimapf g
For a version that ignores the results, see bitraverse_.
Examples
Basic usage:
>>>bitraverse listToMaybe (find odd) (Left [])Nothing
>>>bitraverse listToMaybe (find odd) (Left [1, 2, 3])Just (Left 1)
>>>bitraverse listToMaybe (find odd) (Right [4, 5])Just (Right 5)
>>>bitraverse listToMaybe (find odd) ([1, 2, 3], [4, 5])Just (1,5)
>>>bitraverse listToMaybe (find odd) ([], [4, 5])Nothing
Since: base-4.10.0.0
Instances
| Bitraversable Either | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) # | |
| Bitraversable Arg | Since: base-4.10.0.0 |
Defined in Data.Semigroup Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Arg a b -> f (Arg c d) # | |
| Bitraversable Either | |
Defined in Data.Strict.Either Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) # | |
| Bitraversable These | |
Defined in Data.Strict.These Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> These a b -> f (These c d) # | |
| Bitraversable Pair | |
Defined in Data.Strict.Tuple Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Pair a b -> f (Pair c d) # | |
| Bitraversable These | |
Defined in Data.These Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> These a b -> f (These c d) # | |
| Bitraversable (,) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (a, b) -> f (c, d) # | |
| Bitraversable (Const :: Type -> Type -> Type) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Const a b -> f (Const c d) # | |
| Traversable f => Bitraversable (FreeF f) | |
Defined in Control.Monad.Trans.Free Methods bitraverse :: Applicative f0 => (a -> f0 c) -> (b -> f0 d) -> FreeF f a b -> f0 (FreeF f c d) # | |
| Bitraversable (Tagged :: Type -> Type -> Type) | |
Defined in Data.Tagged Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Tagged a b -> f (Tagged c d) # | |
| Bitraversable (Constant :: Type -> Type -> Type) | |
Defined in Data.Functor.Constant Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Constant a b -> f (Constant c d) # | |
| Bitraversable ((,,) x) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, a, b) -> f (x, c, d) # | |
| Bitraversable (K1 i :: Type -> Type -> Type) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> K1 i a b -> f (K1 i c d) # | |
| Bitraversable ((,,,) x y) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, a, b) -> f (x, y, c, d) # | |
| Traversable f => Bitraversable (Clown f :: Type -> Type -> Type) | |
Defined in Data.Bifunctor.Clown Methods bitraverse :: Applicative f0 => (a -> f0 c) -> (b -> f0 d) -> Clown f a b -> f0 (Clown f c d) # | |
| Bitraversable p => Bitraversable (Flip p) | |
Defined in Data.Bifunctor.Flip Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Flip p a b -> f (Flip p c d) # | |
| Traversable g => Bitraversable (Joker g :: Type -> Type -> Type) | |
Defined in Data.Bifunctor.Joker Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Joker g a b -> f (Joker g c d) # | |
| Bitraversable p => Bitraversable (WrappedBifunctor p) | |
Defined in Data.Bifunctor.Wrapped Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> WrappedBifunctor p a b -> f (WrappedBifunctor p c d) # | |
| Bitraversable ((,,,,) x y z) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, a, b) -> f (x, y, z, c, d) # | |
| (Bitraversable f, Bitraversable g) => Bitraversable (Product f g) | |
Defined in Data.Bifunctor.Product Methods bitraverse :: Applicative f0 => (a -> f0 c) -> (b -> f0 d) -> Product f g a b -> f0 (Product f g c d) # | |
| (Bitraversable p, Bitraversable q) => Bitraversable (Sum p q) | |
Defined in Data.Bifunctor.Sum Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Sum p q a b -> f (Sum p q c d) # | |
| Bitraversable ((,,,,,) x y z w) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, w, a, b) -> f (x, y, z, w, c, d) # | |
| (Traversable f, Bitraversable p) => Bitraversable (Tannen f p) | |
Defined in Data.Bifunctor.Tannen Methods bitraverse :: Applicative f0 => (a -> f0 c) -> (b -> f0 d) -> Tannen f p a b -> f0 (Tannen f p c d) # | |
| Bitraversable ((,,,,,,) x y z w v) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> (x, y, z, w, v, a, b) -> f (x, y, z, w, v, c, d) # | |
| (Bitraversable p, Traversable f, Traversable g) => Bitraversable (Biff p f g) | |
Defined in Data.Bifunctor.Biff Methods bitraverse :: Applicative f0 => (a -> f0 c) -> (b -> f0 d) -> Biff p f g a b -> f0 (Biff p f g c d) # | |
bisequence :: (Bitraversable t, Applicative f) => t (f a) (f b) -> f (t a b) #
Sequences all the actions in a structure, building a new structure with
the same shape using the results of the actions. For a version that ignores
the results, see bisequence_.
bisequence≡bitraverseidid
Examples
Basic usage:
>>>bisequence (Just 4, Nothing)Nothing
>>>bisequence (Just 4, Just 5)Just (4,5)
>>>bisequence ([1, 2, 3], [4, 5])[(1,4),(1,5),(2,4),(2,5),(3,4),(3,5)]
Since: base-4.10.0.0
bimapDefault :: Bitraversable t => (a -> b) -> (c -> d) -> t a c -> t b d #
A default definition of bimap in terms of the Bitraversable
operations.
bimapDefaultf g ≡runIdentity.bitraverse(Identity. f) (Identity. g)
Since: base-4.10.0.0
bifor :: (Bitraversable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f (t c d) #
bifor is bitraverse with the structure as the first argument. For a
version that ignores the results, see bifor_.
Examples
Basic usage:
>>>bifor (Left []) listToMaybe (find even)Nothing
>>>bifor (Left [1, 2, 3]) listToMaybe (find even)Just (Left 1)
>>>bifor (Right [4, 5]) listToMaybe (find even)Just (Right 4)
>>>bifor ([1, 2, 3], [4, 5]) listToMaybe (find even)Just (1,4)
>>>bifor ([], [4, 5]) listToMaybe (find even)Nothing
Since: base-4.10.0.0
bifoldMapDefault :: (Bitraversable t, Monoid m) => (a -> m) -> (b -> m) -> t a b -> m #
A default definition of bifoldMap in terms of the Bitraversable
operations.
bifoldMapDefaultf g ≡getConst.bitraverse(Const. f) (Const. g)
Since: base-4.10.0.0
class Bifoldable (p :: TYPE LiftedRep -> TYPE LiftedRep -> Type) where #
Bifoldable identifies foldable structures with two different varieties
of elements (as opposed to Foldable, which has one variety of element).
Common examples are Either and (,):
instance Bifoldable Either where bifoldMap f _ (Left a) = f a bifoldMap _ g (Right b) = g b instance Bifoldable (,) where bifoldr f g z (a, b) = f a (g b z)
Some examples below also use the following BiList to showcase empty
Bifoldable behaviors when relevant (Either and (,) containing always exactly
resp. 1 and 2 elements):
data BiList a b = BiList [a] [b] instance Bifoldable BiList where bifoldr f g z (BiList as bs) = foldr f (foldr g z bs) as
A minimal Bifoldable definition consists of either bifoldMap or
bifoldr. When defining more than this minimal set, one should ensure
that the following identities hold:
bifold≡bifoldMapididbifoldMapf g ≡bifoldr(mappend. f) (mappend. g)memptybifoldrf g z t ≡appEndo(bifoldMap(Endo . f) (Endo . g) t) z
If the type is also a Bifunctor instance, it should satisfy:
bifoldMapf g ≡bifold.bimapf g
which implies that
bifoldMapf g .bimaph i ≡bifoldMap(f . h) (g . i)
Since: base-4.10.0.0
Methods
bifold :: Monoid m => p m m -> m #
Combines the elements of a structure using a monoid.
bifold≡bifoldMapidid
Examples
Basic usage:
>>>bifold (Right [1, 2, 3])[1,2,3]
>>>bifold (Left [5, 6])[5,6]
>>>bifold ([1, 2, 3], [4, 5])[1,2,3,4,5]
>>>bifold (Product 6, Product 7)Product {getProduct = 42}
>>>bifold (Sum 6, Sum 7)Sum {getSum = 13}
Since: base-4.10.0.0
bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> p a b -> m #
Combines the elements of a structure, given ways of mapping them to a common monoid.
bifoldMapf g ≡bifoldr(mappend. f) (mappend. g)mempty
Examples
Basic usage:
>>>bifoldMap (take 3) (fmap digitToInt) ([1..], "89")[1,2,3,8,9]
>>>bifoldMap (take 3) (fmap digitToInt) (Left [1..])[1,2,3]
>>>bifoldMap (take 3) (fmap digitToInt) (Right "89")[8,9]
Since: base-4.10.0.0
bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> p a b -> c #
Combines the elements of a structure in a right associative manner.
Given a hypothetical function toEitherList :: p a b -> [Either a b]
yielding a list of all elements of a structure in order, the following
would hold:
bifoldrf g z ≡foldr(eitherf g) z . toEitherList
Examples
Basic usage:
> bifoldr (+) (*) 3 (5, 7) 26 -- 5 + (7 * 3) > bifoldr (+) (*) 3 (7, 5) 22 -- 7 + (5 * 3) > bifoldr (+) (*) 3 (Right 5) 15 -- 5 * 3 > bifoldr (+) (*) 3 (Left 5) 8 -- 5 + 3
Since: base-4.10.0.0
bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> p a b -> c #
Combines the elements of a structure in a left associative manner. Given
a hypothetical function toEitherList :: p a b -> [Either a b] yielding a
list of all elements of a structure in order, the following would hold:
bifoldlf g z ≡foldl(acc ->either(f acc) (g acc)) z . toEitherList
Note that if you want an efficient left-fold, you probably want to use
bifoldl' instead of bifoldl. The reason is that the latter does not
force the "inner" results, resulting in a thunk chain which then must be
evaluated from the outside-in.
Examples
Basic usage:
> bifoldl (+) (*) 3 (5, 7) 56 -- (5 + 3) * 7 > bifoldl (+) (*) 3 (7, 5) 50 -- (7 + 3) * 5 > bifoldl (+) (*) 3 (Right 5) 15 -- 5 * 3 > bifoldl (+) (*) 3 (Left 5) 8 -- 5 + 3
Since: base-4.10.0.0
Instances
bitraverse_ :: (Bifoldable t, Applicative f) => (a -> f c) -> (b -> f d) -> t a b -> f () #
Map each element of a structure using one of two actions, evaluate these
actions from left to right, and ignore the results. For a version that
doesn't ignore the results, see bitraverse.
Examples
Basic usage:
>>>bitraverse_ print (print . show) ("Hello", True)"Hello" "True"
>>>bitraverse_ print (print . show) (Right True)"True"
>>>bitraverse_ print (print . show) (Left "Hello")"Hello"
Since: base-4.10.0.0
bisequence_ :: (Bifoldable t, Applicative f) => t (f a) (f b) -> f () #
Evaluate each action in the structure from left to right, and ignore the
results. For a version that doesn't ignore the results, see
bisequence.
Examples
Basic usage:
>>>bisequence_ (print "Hello", print "World")"Hello" "World"
>>>bisequence_ (Left (print "Hello"))"Hello"
>>>bisequence_ (Right (print "World"))"World"
Since: base-4.10.0.0
bior :: Bifoldable t => t Bool Bool -> Bool #
bior returns the disjunction of a container of Bools. For the
result to be False, the container must be finite; True, however,
results from a True value finitely far from the left end.
Examples
Basic usage:
>>>bior (True, False)True
>>>bior (False, False)False
>>>bior (Left True)True
Empty structures yield False:
>>>bior (BiList [] [])False
A True value finitely far from the left end yields True (short circuit):
>>>bior (BiList [False, False, True, False] (repeat False))True
A True value infinitely far from the left end hangs:
> bior (BiList (repeat False) [True]) * Hangs forever *
An infinitely False value hangs:
> bior (BiList (repeat False) []) * Hangs forever *
Since: base-4.10.0.0
binull :: Bifoldable t => t a b -> Bool #
Test whether the structure is empty.
Examples
Basic usage:
>>>binull (18, 42)False
>>>binull (Right 42)False
>>>binull (BiList [] [])True
Since: base-4.10.0.0
bilength :: Bifoldable t => t a b -> Int #
Returns the size/length of a finite structure as an Int.
Examples
Basic usage:
>>>bilength (True, 42)2
>>>bilength (Right 42)1
>>>bilength (BiList [1,2,3] [4,5])5
>>>bilength (BiList [] [])0
On infinite structures, this function hangs:
> bilength (BiList [1..] []) * Hangs forever *
Since: base-4.10.0.0
bifor_ :: (Bifoldable t, Applicative f) => t a b -> (a -> f c) -> (b -> f d) -> f () #
As bitraverse_, but with the structure as the primary argument. For a
version that doesn't ignore the results, see bifor.
Examples
Basic usage:
>>>bifor_ ("Hello", True) print (print . show)"Hello" "True"
>>>bifor_ (Right True) print (print . show)"True"
>>>bifor_ (Left "Hello") print (print . show)"Hello"
Since: base-4.10.0.0
bifoldrM :: (Bifoldable t, Monad m) => (a -> c -> m c) -> (b -> c -> m c) -> c -> t a b -> m c #
Right associative monadic bifold over a structure.
Since: base-4.10.0.0
bifoldr' :: Bifoldable t => (a -> c -> c) -> (b -> c -> c) -> c -> t a b -> c #
As bifoldr, but strict in the result of the reduction functions at each
step.
Since: base-4.10.0.0
bifoldlM :: (Bifoldable t, Monad m) => (a -> b -> m a) -> (a -> c -> m a) -> a -> t b c -> m a #
Left associative monadic bifold over a structure.
Examples
Basic usage:
>>>bifoldlM (\a b -> print b >> pure a) (\a c -> print (show c) >> pure a) 42 ("Hello", True)"Hello" "True" 42
>>>bifoldlM (\a b -> print b >> pure a) (\a c -> print (show c) >> pure a) 42 (Right True)"True" 42
>>>bifoldlM (\a b -> print b >> pure a) (\a c -> print (show c) >> pure a) 42 (Left "Hello")"Hello" 42
Since: base-4.10.0.0
bifoldl' :: Bifoldable t => (a -> b -> a) -> (a -> c -> a) -> a -> t b c -> a #
As bifoldl, but strict in the result of the reduction functions at each
step.
This ensures that each step of the bifold is forced to weak head normal form
before being applied, avoiding the collection of thunks that would otherwise
occur. This is often what you want to strictly reduce a finite structure to
a single, monolithic result (e.g., bilength).
Since: base-4.10.0.0
bifind :: Bifoldable t => (a -> Bool) -> t a a -> Maybe a #
The bifind function takes a predicate and a structure and returns
the leftmost element of the structure matching the predicate, or
Nothing if there is no such element.
Examples
Basic usage:
>>>bifind even (27, 53)Nothing
>>>bifind even (27, 52)Just 52
>>>bifind even (26, 52)Just 26
Empty structures always yield Nothing:
>>>bifind even (BiList [] [])Nothing
Since: base-4.10.0.0
bielem :: (Bifoldable t, Eq a) => a -> t a a -> Bool #
Does the element occur in the structure?
Examples
Basic usage:
>>>bielem 42 (17, 42)True
>>>bielem 42 (17, 43)False
>>>bielem 42 (Left 42)True
>>>bielem 42 (Right 13)False
>>>bielem 42 (BiList [1..5] [1..100])True
>>>bielem 42 (BiList [1..5] [1..41])False
Since: base-4.10.0.0
biasum :: (Bifoldable t, Alternative f) => t (f a) (f a) -> f a #
The sum of a collection of actions, generalizing biconcat.
Examples
Basic usage:
>>>biasum (Nothing, Nothing)Nothing
>>>biasum (Nothing, Just 42)Just 42
>>>biasum (Just 18, Nothing)Just 18
>>>biasum (Just 18, Just 42)Just 18
Since: base-4.10.0.0
biany :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool #
Determines whether any element of the structure satisfies its appropriate
predicate argument. Empty structures yield False.
Examples
Basic usage:
>>>biany even isDigit (27, 't')False
>>>biany even isDigit (27, '8')True
>>>biany even isDigit (26, 't')True
>>>biany even isDigit (Left 27)False
>>>biany even isDigit (Left 26)True
>>>biany even isDigit (BiList [27, 53] ['t', '8'])True
Empty structures yield False:
>>>biany even isDigit (BiList [] [])False
Since: base-4.10.0.0
biand :: Bifoldable t => t Bool Bool -> Bool #
biand returns the conjunction of a container of Bools. For the
result to be True, the container must be finite; False, however,
results from a False value finitely far from the left end.
Examples
Basic usage:
>>>biand (True, False)False
>>>biand (True, True)True
>>>biand (Left True)True
Empty structures yield True:
>>>biand (BiList [] [])True
A False value finitely far from the left end yields False (short circuit):
>>>biand (BiList [True, True, False, True] (repeat True))False
A False value infinitely far from the left end hangs:
> biand (BiList (repeat True) [False]) * Hangs forever *
An infinitely True value hangs:
> biand (BiList (repeat True) []) * Hangs forever *
Since: base-4.10.0.0
biall :: Bifoldable t => (a -> Bool) -> (b -> Bool) -> t a b -> Bool #
Determines whether all elements of the structure satisfy their appropriate
predicate argument. Empty structures yield True.
Examples
Basic usage:
>>>biall even isDigit (27, 't')False
>>>biall even isDigit (26, '8')True
>>>biall even isDigit (Left 27)False
>>>biall even isDigit (Left 26)True
>>>biall even isDigit (BiList [26, 52] ['3', '8'])True
Empty structures yield True:
>>>biall even isDigit (BiList [] [])True
Since: base-4.10.0.0
biList :: Bifoldable t => t a a -> [a] #
Collects the list of elements of a structure, from left to right.
Examples
Basic usage:
>>>biList (18, 42)[18,42]
>>>biList (Left 18)[18]
Since: base-4.10.0.0
showStackTrace :: IO (Maybe String) #
Get a string representation of the current execution stack state.
getStackTrace :: IO (Maybe [Location]) #
Get a trace of the current execution stack state.
Returns Nothing if stack trace support isn't available on host machine.
class Monad m => MonadIO (m :: Type -> Type) where #
Monads in which IO computations may be embedded.
Any monad built by applying a sequence of monad transformers to the
IO monad will be an instance of this class.
Instances should satisfy the following laws, which state that liftIO
is a transformer of monads:
Methods
Lift a computation from the IO monad.
This allows us to run IO computations in any monadic stack, so long as it supports these kinds of operations
(i.e. IO is the base monad for the stack).
Example
import Control.Monad.Trans.State -- from the "transformers" library printState :: Show s => StateT s IO () printState = do state <- get liftIO $ print state
Had we omitted liftIO
• Couldn't match type ‘IO’ with ‘StateT s IO’ Expected type: StateT s IO () Actual type: IO ()
The important part here is the mismatch between StateT s IO () and IO ()
Luckily, we know of a function that takes an IO a(m a): liftIO
> evalStateT printState "hello" "hello" > evalStateT printState 3 3
Instances
zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m () #
zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c] #
unless :: Applicative f => Bool -> f () -> f () #
The reverse of when.
replicateM_ :: Applicative m => Int -> m a -> m () #
replicateM :: Applicative m => Int -> m a -> m [a] #
replicateM n actact n times,
and then returns the list of results:
Examples
>>>import Control.Monad.State>>>runState (replicateM 3 $ state $ \s -> (s, s + 1)) 1([1,2,3],4)
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c]) #
The mapAndUnzipM function maps its first argument over a list, returning
the result as a pair of lists. This function is mainly used with complicated
data structures or a state monad.
forever :: Applicative f => f a -> f b #
Repeat an action indefinitely.
Examples
A common use of forever is to process input from network sockets,
Handles, and channels
(e.g. MVar and
Chan).
For example, here is how we might implement an echo
server, using
forever both to listen for client connections on a network socket
and to echo client input on client connection handles:
echoServer :: Socket -> IO () echoServer socket =forever$ do client <- accept socketforkFinally(echo client) (\_ -> hClose client) where echo :: Handle -> IO () echo client =forever$ hGetLine client >>= hPutStrLn client
Note that "forever" isn't necessarily non-terminating.
If the action is in a MonadPlusforevermzero, effectively short-circuiting its caller.
filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a] #
This generalizes the list-based filter function.
mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b) #
The mapAccumR function behaves like a combination of fmap
and foldr; it applies a function to each element of a structure,
passing an accumulating parameter from right to left, and returning
a final value of this accumulator together with the new structure.
Examples
Basic usage:
>>>mapAccumR (\a b -> (a + b, a)) 0 [1..10](55,[54,52,49,45,40,34,27,19,10,0])
>>>mapAccumR (\a b -> (a <> show b, a)) "0" [1..5]("054321",["05432","0543","054","05","0"])
mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b) #
The mapAccumL function behaves like a combination of fmap
and foldl; it applies a function to each element of a structure,
passing an accumulating parameter from left to right, and returning
a final value of this accumulator together with the new structure.
Examples
Basic usage:
>>>mapAccumL (\a b -> (a + b, a)) 0 [1..10](55,[0,1,3,6,10,15,21,28,36,45])
>>>mapAccumL (\a b -> (a <> show b, a)) "0" [1..5]("012345",["0","01","012","0123","01234"])
forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b) #
Lists, but with an Applicative functor based on zipping.
Constructors
| ZipList | |
Fields
| |
Instances
| Foldable ZipList | Since: base-4.9.0.0 |
Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # | |
| Traversable ZipList | Since: base-4.9.0.0 |
| Alternative ZipList | Since: base-4.11.0.0 |
| Applicative ZipList | f <$> ZipList xs1 <*> ... <*> ZipList xsN
= ZipList (zipWithN f xs1 ... xsN)where (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <*> ZipList "567" <*> ZipList [1..]
= ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..])
= ZipList {getZipList = ["a5","b6b6","c7c7c7"]}Since: base-2.1 |
| Functor ZipList | Since: base-2.1 |
| NFData1 ZipList | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Align ZipList | |
Defined in Data.Semialign.Internal | |
| Repeat ZipList | |
Defined in Data.Semialign.Internal | |
| Semialign ZipList |
|
| Unzip ZipList | |
| Zip ZipList | |
| Generic1 ZipList | |
| FoldableWithIndex Int ZipList | |
Defined in WithIndex | |
| FunctorWithIndex Int ZipList | Same instance as for |
| TraversableWithIndex Int ZipList | |
| RepeatWithIndex Int ZipList | |
Defined in Data.Semialign.Internal | |
| SemialignWithIndex Int ZipList | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Int ZipList | |
| Data a => Data (ZipList a) | Since: base-4.14.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ZipList a -> c (ZipList a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (ZipList a) # toConstr :: ZipList a -> Constr # dataTypeOf :: ZipList a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (ZipList a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (ZipList a)) # gmapT :: (forall b. Data b => b -> b) -> ZipList a -> ZipList a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ZipList a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ZipList a -> r # gmapQ :: (forall d. Data d => d -> u) -> ZipList a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> ZipList a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> ZipList a -> m (ZipList a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ZipList a -> m (ZipList a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ZipList a -> m (ZipList a) # | |
| IsList (ZipList a) | Since: base-4.15.0.0 |
| Generic (ZipList a) | |
| Read a => Read (ZipList a) | Since: base-4.7.0.0 |
| Show a => Show (ZipList a) | Since: base-4.7.0.0 |
| NFData a => NFData (ZipList a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (ZipList a) | Since: base-4.7.0.0 |
| Ord a => Ord (ZipList a) | Since: base-4.7.0.0 |
| Serialise a => Serialise (ZipList a) | Since: serialise-0.2.0.0 |
| type Rep1 ZipList | Since: base-4.7.0.0 |
Defined in Control.Applicative | |
| type Item (ZipList a) | |
| type Rep (ZipList a) | Since: base-4.7.0.0 |
Defined in Control.Applicative | |
optional :: Alternative f => f a -> f (Maybe a) #
One or none.
It is useful for modelling any computation that is allowed to fail.
Examples
Using the Alternative instance of Control.Monad.Except, the following functions:
>>>import Control.Monad.Except
>>>canFail = throwError "it failed" :: Except String Int>>>final = return 42 :: Except String Int
Can be combined by allowing the first function to fail:
>>>runExcept $ canFail *> finalLeft "it failed">>>runExcept $ optional canFail *> finalRight 42
(&&&) :: Arrow a => a b c -> a b c' -> a b (c, c') infixr 3 #
Fanout: send the input to both argument arrows and combine their output.
The default definition may be overridden with a more efficient version if desired.
Identity functor and monad. (a non-strict monad)
Since: base-4.8.0.0
Constructors
| Identity | |
Fields
| |
Instances
withFrozenCallStack :: HasCallStack => (HasCallStack => a) -> a #
Perform some computation without adding new entries to the CallStack.
Since: base-4.9.0.0
callStack :: HasCallStack => CallStack #
Shared memory locations that support atomic memory transactions.
A monad supporting atomic memory transactions.
Instances
throwSTM :: Exception e => e -> STM a #
A variant of throw that can only be used within the STM monad.
Throwing an exception in STM aborts the transaction and propagates the
exception. If the exception is caught via catchSTM, only the changes
enclosed by the catch are rolled back; changes made outside of catchSTM
persist.
If the exception is not caught inside of the STM, it is re-thrown by
atomically, and the entire STM is rolled back.
Although throwSTM has a type that is an instance of the type of throw, the
two functions are subtly different:
throw e `seq` x ===> throw e throwSTM e `seq` x ===> x
The first example will cause the exception e to be raised,
whereas the second one won't. In fact, throwSTM will only cause
an exception to be raised when it is used within the STM monad.
The throwSTM variant should be used in preference to throw to
raise an exception within the STM monad because it guarantees
ordering with respect to other STM operations, whereas throw
does not.
data BufferMode #
Three kinds of buffering are supported: line-buffering, block-buffering or no-buffering. These modes have the following effects. For output, items are written out, or flushed, from the internal buffer according to the buffer mode:
- line-buffering: the entire output buffer is flushed
whenever a newline is output, the buffer overflows,
a
hFlushis issued, or the handle is closed. - block-buffering: the entire buffer is written out whenever it
overflows, a
hFlushis issued, or the handle is closed. - no-buffering: output is written immediately, and never stored in the buffer.
An implementation is free to flush the buffer more frequently, but not less frequently, than specified above. The output buffer is emptied as soon as it has been written out.
Similarly, input occurs according to the buffer mode for the handle:
- line-buffering: when the buffer for the handle is not empty, the next item is obtained from the buffer; otherwise, when the buffer is empty, characters up to and including the next newline character are read into the buffer. No characters are available until the newline character is available or the buffer is full.
- block-buffering: when the buffer for the handle becomes empty, the next block of data is read into the buffer.
- no-buffering: the next input item is read and returned.
The
hLookAheadoperation implies that even a no-buffered handle may require a one-character buffer.
The default buffering mode when a handle is opened is implementation-dependent and may depend on the file system object which is attached to that handle. For most implementations, physical files will normally be block-buffered and terminals will normally be line-buffered.
Constructors
| NoBuffering | buffering is disabled if possible. |
| LineBuffering | line-buffering should be enabled if possible. |
| BlockBuffering (Maybe Int) | block-buffering should be enabled if possible.
The size of the buffer is |
Instances
| Read BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods readsPrec :: Int -> ReadS BufferMode # readList :: ReadS [BufferMode] # readPrec :: ReadPrec BufferMode # readListPrec :: ReadPrec [BufferMode] # | |
| Show BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods showsPrec :: Int -> BufferMode -> ShowS # show :: BufferMode -> String # showList :: [BufferMode] -> ShowS # | |
| Eq BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types | |
| Ord BufferMode | Since: base-4.2.0.0 |
Defined in GHC.IO.Handle.Types Methods compare :: BufferMode -> BufferMode -> Ordering # (<) :: BufferMode -> BufferMode -> Bool # (<=) :: BufferMode -> BufferMode -> Bool # (>) :: BufferMode -> BufferMode -> Bool # (>=) :: BufferMode -> BufferMode -> Bool # max :: BufferMode -> BufferMode -> BufferMode # min :: BufferMode -> BufferMode -> BufferMode # | |
A mutable variable in the IO monad
File and directory names are values of type String, whose precise
meaning is operating system dependent. Files can be opened, yielding a
handle which can then be used to operate on the contents of that file.
prettySrcLoc :: SrcLoc -> String #
Pretty print a SrcLoc.
Since: base-4.9.0.0
prettyCallStack :: CallStack -> String #
Pretty print a CallStack.
Since: base-4.9.0.0
class (Typeable e, Show e) => Exception e where #
Any type that you wish to throw or catch as an exception must be an
instance of the Exception class. The simplest case is a new exception
type directly below the root:
data MyException = ThisException | ThatException
deriving Show
instance Exception MyExceptionThe default method definitions in the Exception class do what we need
in this case. You can now throw and catch ThisException and
ThatException as exceptions:
*Main> throw ThisException `catch` \e -> putStrLn ("Caught " ++ show (e :: MyException))
Caught ThisException
In more complicated examples, you may wish to define a whole hierarchy of exceptions:
---------------------------------------------------------------------
-- Make the root exception type for all the exceptions in a compiler
data SomeCompilerException = forall e . Exception e => SomeCompilerException e
instance Show SomeCompilerException where
show (SomeCompilerException e) = show e
instance Exception SomeCompilerException
compilerExceptionToException :: Exception e => e -> SomeException
compilerExceptionToException = toException . SomeCompilerException
compilerExceptionFromException :: Exception e => SomeException -> Maybe e
compilerExceptionFromException x = do
SomeCompilerException a <- fromException x
cast a
---------------------------------------------------------------------
-- Make a subhierarchy for exceptions in the frontend of the compiler
data SomeFrontendException = forall e . Exception e => SomeFrontendException e
instance Show SomeFrontendException where
show (SomeFrontendException e) = show e
instance Exception SomeFrontendException where
toException = compilerExceptionToException
fromException = compilerExceptionFromException
frontendExceptionToException :: Exception e => e -> SomeException
frontendExceptionToException = toException . SomeFrontendException
frontendExceptionFromException :: Exception e => SomeException -> Maybe e
frontendExceptionFromException x = do
SomeFrontendException a <- fromException x
cast a
---------------------------------------------------------------------
-- Make an exception type for a particular frontend compiler exception
data MismatchedParentheses = MismatchedParentheses
deriving Show
instance Exception MismatchedParentheses where
toException = frontendExceptionToException
fromException = frontendExceptionFromExceptionWe can now catch a MismatchedParentheses exception as
MismatchedParentheses, SomeFrontendException or
SomeCompilerException, but not other types, e.g. IOException:
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: MismatchedParentheses))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeFrontendException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: SomeCompilerException))
Caught MismatchedParentheses
*Main> throw MismatchedParentheses `catch` \e -> putStrLn ("Caught " ++ show (e :: IOException))
*** Exception: MismatchedParentheses
Minimal complete definition
Nothing
Methods
toException :: e -> SomeException #
fromException :: SomeException -> Maybe e #
displayException :: e -> String #
Render this exception value in a human-friendly manner.
Default implementation: show
Since: base-4.8.0.0
Instances
The Const functor.
Instances
| Generic1 (Const a :: k -> Type) | |
| FoldableWithIndex Void (Const e :: Type -> Type) | |
Defined in WithIndex | |
| FunctorWithIndex Void (Const e :: Type -> Type) | |
| TraversableWithIndex Void (Const e :: Type -> Type) | |
| Unbox a => Vector Vector (Const a b) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Const a b) -> ST s (Vector (Const a b)) # basicUnsafeThaw :: Vector (Const a b) -> ST s (Mutable Vector s (Const a b)) # basicLength :: Vector (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Const a b) -> Vector (Const a b) # basicUnsafeIndexM :: Vector (Const a b) -> Int -> Box (Const a b) # basicUnsafeCopy :: Mutable Vector s (Const a b) -> Vector (Const a b) -> ST s () # | |
| Unbox a => MVector MVector (Const a b) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Const a b) -> MVector s (Const a b) # basicOverlaps :: MVector s (Const a b) -> MVector s (Const a b) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Const a b)) # basicInitialize :: MVector s (Const a b) -> ST s () # basicUnsafeReplicate :: Int -> Const a b -> ST s (MVector s (Const a b)) # basicUnsafeRead :: MVector s (Const a b) -> Int -> ST s (Const a b) # basicUnsafeWrite :: MVector s (Const a b) -> Int -> Const a b -> ST s () # basicClear :: MVector s (Const a b) -> ST s () # basicSet :: MVector s (Const a b) -> Const a b -> ST s () # basicUnsafeCopy :: MVector s (Const a b) -> MVector s (Const a b) -> ST s () # basicUnsafeMove :: MVector s (Const a b) -> MVector s (Const a b) -> ST s () # basicUnsafeGrow :: MVector s (Const a b) -> Int -> ST s (MVector s (Const a b)) # | |
| FromJSON2 (Const :: Type -> Type -> Type) | |
Defined in Data.Aeson.Types.FromJSON | |
| ToJSON2 (Const :: Type -> TYPE LiftedRep -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> Const a b -> Value # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [Const a b] -> Value # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> Const a b -> Encoding # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [Const a b] -> Encoding # | |
| Bifoldable (Const :: Type -> TYPE LiftedRep -> Type) | Since: base-4.10.0.0 |
| Bifunctor (Const :: Type -> Type -> Type) | Since: base-4.8.0.0 |
| Bitraversable (Const :: Type -> Type -> Type) | Since: base-4.10.0.0 |
Defined in Data.Bitraversable Methods bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Const a b -> f (Const c d) # | |
| Eq2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
| Ord2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read2 (Const :: Type -> Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Const a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Const a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Const a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Const a b] # | |
| Show2 (Const :: Type -> TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
| Biapplicative (Const :: Type -> Type -> Type) | |
Defined in Data.Biapplicative | |
| NFData2 (Const :: Type -> Type -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable2 (Const :: Type -> Type -> Type) | |
Defined in Data.Hashable.Class | |
| FromJSON a => FromJSON1 (Const a :: Type -> Type) | |
| ToJSON a => ToJSON1 (Const a :: TYPE LiftedRep -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> Const a a0 -> Value # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [Const a a0] -> Value # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> Const a a0 -> Encoding # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [Const a a0] -> Encoding # | |
| Foldable (Const m :: TYPE LiftedRep -> Type) | Since: base-4.7.0.0 |
Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # | |
| Eq a => Eq1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
| Ord a => Ord1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read a => Read1 (Const a :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Const a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Const a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Const a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Const a a0] # | |
| Show a => Show1 (Const a :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
| Contravariant (Const a :: Type -> Type) | |
| Traversable (Const m :: Type -> Type) | Since: base-4.7.0.0 |
| Monoid m => Applicative (Const m :: Type -> Type) | Since: base-2.0.1 |
| Functor (Const m :: Type -> Type) | Since: base-2.1 |
| NFData a => NFData1 (Const a :: TYPE LiftedRep -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable a => Hashable1 (Const a :: Type -> Type) | |
Defined in Data.Hashable.Class | |
| Phantom (Const a :: Type -> Type) | |
Defined in Lens.Family.Phantom | |
| FromJSON a => FromJSON (Const a b) | |
| (FromJSON a, FromJSONKey a) => FromJSONKey (Const a b) | |
Defined in Data.Aeson.Types.FromJSON Methods fromJSONKey :: FromJSONKeyFunction (Const a b) # fromJSONKeyList :: FromJSONKeyFunction [Const a b] # | |
| ToJSON a => ToJSON (Const a b) | |
Defined in Data.Aeson.Types.ToJSON | |
| (ToJSON a, ToJSONKey a) => ToJSONKey (Const a b) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Typeable k, Data a, Typeable b) => Data (Const a b) | Since: base-4.10.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b0. Data d => c (d -> b0) -> d -> c b0) -> (forall g. g -> c g) -> Const a b -> c (Const a b) # gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Const a b) # toConstr :: Const a b -> Constr # dataTypeOf :: Const a b -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Const a b)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Const a b)) # gmapT :: (forall b0. Data b0 => b0 -> b0) -> Const a b -> Const a b # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Const a b -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Const a b -> r # gmapQ :: (forall d. Data d => d -> u) -> Const a b -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Const a b -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Const a b -> m (Const a b) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Const a b -> m (Const a b) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Const a b -> m (Const a b) # | |
| IsString a => IsString (Const a b) | Since: base-4.9.0.0 |
Defined in Data.String Methods fromString :: String -> Const a b # | |
| Storable a => Storable (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| Monoid a => Monoid (Const a b) | Since: base-4.9.0.0 |
| Semigroup a => Semigroup (Const a b) | Since: base-4.9.0.0 |
| Bits a => Bits (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods (.&.) :: Const a b -> Const a b -> Const a b # (.|.) :: Const a b -> Const a b -> Const a b # xor :: Const a b -> Const a b -> Const a b # complement :: Const a b -> Const a b # shift :: Const a b -> Int -> Const a b # rotate :: Const a b -> Int -> Const a b # setBit :: Const a b -> Int -> Const a b # clearBit :: Const a b -> Int -> Const a b # complementBit :: Const a b -> Int -> Const a b # testBit :: Const a b -> Int -> Bool # bitSizeMaybe :: Const a b -> Maybe Int # isSigned :: Const a b -> Bool # shiftL :: Const a b -> Int -> Const a b # unsafeShiftL :: Const a b -> Int -> Const a b # shiftR :: Const a b -> Int -> Const a b # unsafeShiftR :: Const a b -> Int -> Const a b # rotateL :: Const a b -> Int -> Const a b # | |
| FiniteBits a => FiniteBits (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods finiteBitSize :: Const a b -> Int # countLeadingZeros :: Const a b -> Int # countTrailingZeros :: Const a b -> Int # | |
| Bounded a => Bounded (Const a b) | Since: base-4.9.0.0 |
| Enum a => Enum (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods succ :: Const a b -> Const a b # pred :: Const a b -> Const a b # fromEnum :: Const a b -> Int # enumFrom :: Const a b -> [Const a b] # enumFromThen :: Const a b -> Const a b -> [Const a b] # enumFromTo :: Const a b -> Const a b -> [Const a b] # enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b] # | |
| Floating a => Floating (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # | |
| RealFloat a => RealFloat (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods floatRadix :: Const a b -> Integer # floatDigits :: Const a b -> Int # floatRange :: Const a b -> (Int, Int) # decodeFloat :: Const a b -> (Integer, Int) # encodeFloat :: Integer -> Int -> Const a b # exponent :: Const a b -> Int # significand :: Const a b -> Const a b # scaleFloat :: Int -> Const a b -> Const a b # isInfinite :: Const a b -> Bool # isDenormalized :: Const a b -> Bool # isNegativeZero :: Const a b -> Bool # | |
| Generic (Const a b) | |
| Ix a => Ix (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods range :: (Const a b, Const a b) -> [Const a b] # index :: (Const a b, Const a b) -> Const a b -> Int # unsafeIndex :: (Const a b, Const a b) -> Const a b -> Int # inRange :: (Const a b, Const a b) -> Const a b -> Bool # rangeSize :: (Const a b, Const a b) -> Int # unsafeRangeSize :: (Const a b, Const a b) -> Int # | |
| Num a => Num (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| Read a => Read (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| Fractional a => Fractional (Const a b) | Since: base-4.9.0.0 |
| Integral a => Integral (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # | |
| Real a => Real (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational # | |
| RealFrac a => RealFrac (Const a b) | Since: base-4.9.0.0 |
| Show a => Show (Const a b) | This instance would be equivalent to the derived instances of the
Since: base-4.8.0.0 |
| NFData a => NFData (Const a b) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Const a b) | Since: base-4.9.0.0 |
| Ord a => Ord (Const a b) | Since: base-4.9.0.0 |
| Hashable a => Hashable (Const a b) | |
Defined in Data.Hashable.Class | |
| Pretty a => Pretty (Const a b) | |
Defined in Prettyprinter.Internal | |
| Prim a => Prim (Const a b) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods sizeOf# :: Const a b -> Int# # alignment# :: Const a b -> Int# # indexByteArray# :: ByteArray# -> Int# -> Const a b # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Const a b #) # writeByteArray# :: MutableByteArray# s -> Int# -> Const a b -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Const a b -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Const a b # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Const a b #) # writeOffAddr# :: Addr# -> Int# -> Const a b -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Const a b -> State# s -> State# s # | |
| Serialise a => Serialise (Const a b) | Since: serialise-0.2.0.0 |
| Unbox a => Unbox (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Const a :: k -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| newtype MVector s (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Const a b) | Since: base-4.9.0.0 |
Defined in Data.Functor.Const | |
| newtype Vector (Const a b) | |
Defined in Data.Vector.Unboxed.Base | |
traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f () #
Map each element of a structure to an Applicative action, evaluate these
actions from left to right, and ignore the results. For a version that
doesn't ignore the results see traverse.
traverse_ is just like mapM_, but generalised to Applicative actions.
Examples
Basic usage:
>>>traverse_ print ["Hello", "world", "!"]"Hello" "world" "!"
sequence_ :: (Foldable t, Monad m) => t (m a) -> m () #
Evaluate each monadic action in the structure from left to right,
and ignore the results. For a version that doesn't ignore the
results see sequence.
sequence_ is just like sequenceA_, but specialised to monadic
actions.
sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f () #
Evaluate each action in the structure from left to right, and
ignore the results. For a version that doesn't ignore the results
see sequenceA.
sequenceA_ is just like sequence_, but generalised to Applicative
actions.
Examples
Basic usage:
>>>sequenceA_ [print "Hello", print "world", print "!"]"Hello" "world" "!"
or :: Foldable t => t Bool -> Bool #
or returns the disjunction of a container of Bools. For the
result to be False, the container must be finite; True, however,
results from a True value finitely far from the left end.
Examples
Basic usage:
>>>or []False
>>>or [True]True
>>>or [False]False
>>>or [True, True, False]True
>>>or (True : repeat False) -- Infinite list [True,False,False,False,...True
>>>or (repeat False)* Hangs forever *
for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f () #
for_ is traverse_ with its arguments flipped. For a version
that doesn't ignore the results see for. This
is forM_ generalised to Applicative actions.
for_ is just like forM_, but generalised to Applicative actions.
Examples
Basic usage:
>>>for_ [1..4] print1 2 3 4
foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b #
Left-to-right monadic fold over the elements of a structure.
Given a structure t with elements (a, b, ..., w, x, y), the result of
a fold with an operator function f is equivalent to:
foldlM f z t = do
aa <- f z a
bb <- f aa b
...
xx <- f ww x
yy <- f xx y
return yy -- Just @return z@ when the structure is emptyFor a Monad m, given two functions f1 :: a -> m b and f2 :: b -> m c,
their Kleisli composition (f1 >=> f2) :: a -> m c is defined by:
(f1 >=> f2) a = f1 a >>= f2
Another way of thinking about foldlM is that it amounts to an application
to z of a Kleisli composition:
foldlM f z t =
flip f a >=> flip f b >=> ... >=> flip f x >=> flip f y $ zThe monadic effects of foldlM are sequenced from left to right.
If at some step the bind operator ( short-circuits (as with, e.g.,
>>=)mzero in a MonadPlus), the evaluated effects will be from an initial
segment of the element sequence. If you want to evaluate the monadic
effects in right-to-left order, or perhaps be able to short-circuit after
processing a tail of the sequence of elements, you'll need to use foldrM
instead.
If the monadic effects don't short-circuit, the outermost application of
f is to the rightmost element y, so that, ignoring effects, the result
looks like a left fold:
((((z `f` a) `f` b) ... `f` w) `f` x) `f` y
Examples
Basic usage:
>>>let f a e = do { print e ; return $ e : a }>>>foldlM f [] [0..3]0 1 2 3 [3,2,1,0]
concatMap :: Foldable t => (a -> [b]) -> t a -> [b] #
Map a function over all the elements of a container and concatenate the resulting lists.
Examples
Basic usage:
>>>concatMap (take 3) [[1..], [10..], [100..], [1000..]][1,2,3,10,11,12,100,101,102,1000,1001,1002]
>>>concatMap (take 3) (Just [1..])[1,2,3]
asum :: (Foldable t, Alternative f) => t (f a) -> f a #
The sum of a collection of actions, generalizing concat.
asum is just like msum, but generalised to Alternative.
Examples
Basic usage:
>>>asum [Just "Hello", Nothing, Just "World"]Just "Hello"
any :: Foldable t => (a -> Bool) -> t a -> Bool #
Determines whether any element of the structure satisfies the predicate.
Examples
Basic usage:
>>>any (> 3) []False
>>>any (> 3) [1,2]False
>>>any (> 3) [1,2,3,4,5]True
>>>any (> 3) [1..]True
>>>any (> 3) [0, -1..]* Hangs forever *
and :: Foldable t => t Bool -> Bool #
and returns the conjunction of a container of Bools. For the
result to be True, the container must be finite; False, however,
results from a False value finitely far from the left end.
Examples
Basic usage:
>>>and []True
>>>and [True]True
>>>and [False]False
>>>and [True, True, False]False
>>>and (False : repeat True) -- Infinite list [False,True,True,True,...False
>>>and (repeat True)* Hangs forever *
unfoldr :: (b -> Maybe (a, b)) -> b -> [a] #
The unfoldr function is a `dual' to foldr: while foldr
reduces a list to a summary value, unfoldr builds a list from
a seed value. The function takes the element and returns Nothing
if it is done producing the list or returns Just (a,b), in which
case, a is a prepended to the list and b is used as the next
element in a recursive call. For example,
iterate f == unfoldr (\x -> Just (x, f x))
In some cases, unfoldr can undo a foldr operation:
unfoldr f' (foldr f z xs) == xs
if the following holds:
f' (f x y) = Just (x,y) f' z = Nothing
A simple use of unfoldr:
>>>unfoldr (\b -> if b == 0 then Nothing else Just (b, b-1)) 10[10,9,8,7,6,5,4,3,2,1]
subsequences :: [a] -> [[a]] #
The subsequences function returns the list of all subsequences of the argument.
>>>subsequences "abc"["","a","b","ab","c","ac","bc","abc"]
sortOn :: Ord b => (a -> b) -> [a] -> [a] #
Sort a list by comparing the results of a key function applied to each
element. sortOn f is equivalent to sortBy (comparing f), but has the
performance advantage of only evaluating f once for each element in the
input list. This is called the decorate-sort-undecorate paradigm, or
Schwartzian transform.
Elements are arranged from lowest to highest, keeping duplicates in the order they appeared in the input.
>>>sortOn fst [(2, "world"), (4, "!"), (1, "Hello")][(1,"Hello"),(2,"world"),(4,"!")]
Since: base-4.8.0.0
permutations :: [a] -> [[a]] #
The permutations function returns the list of all permutations of the argument.
>>>permutations "abc"["abc","bac","cba","bca","cab","acb"]
isPrefixOf :: Eq a => [a] -> [a] -> Bool #
\(\mathcal{O}(\min(m,n))\). The isPrefixOf function takes two lists and
returns True iff the first list is a prefix of the second.
>>>"Hello" `isPrefixOf` "Hello World!"True
>>>"Hello" `isPrefixOf` "Wello Horld!"False
intersperse :: a -> [a] -> [a] #
\(\mathcal{O}(n)\). The intersperse function takes an element and a list
and `intersperses' that element between the elements of the list. For
example,
>>>intersperse ',' "abcde""a,b,c,d,e"
intercalate :: [a] -> [[a]] -> [a] #
intercalate xs xss is equivalent to (.
It inserts the list concat (intersperse xs xss))xs in between the lists in xss and concatenates the
result.
>>>intercalate ", " ["Lorem", "ipsum", "dolor"]"Lorem, ipsum, dolor"
group :: Eq a => [a] -> [[a]] #
The group function takes a list and returns a list of lists such
that the concatenation of the result is equal to the argument. Moreover,
each sublist in the result contains only equal elements. For example,
>>>group "Mississippi"["M","i","ss","i","ss","i","pp","i"]
It is a special case of groupBy, which allows the programmer to supply
their own equality test.
genericTake :: Integral i => i -> [a] -> [a] #
The genericTake function is an overloaded version of take, which
accepts any Integral value as the number of elements to take.
genericSplitAt :: Integral i => i -> [a] -> ([a], [a]) #
The genericSplitAt function is an overloaded version of splitAt, which
accepts any Integral value as the position at which to split.
genericReplicate :: Integral i => i -> a -> [a] #
The genericReplicate function is an overloaded version of replicate,
which accepts any Integral value as the number of repetitions to make.
genericLength :: Num i => [a] -> i #
\(\mathcal{O}(n)\). The genericLength function is an overloaded version
of length. In particular, instead of returning an Int, it returns any
type which is an instance of Num. It is, however, less efficient than
length.
>>>genericLength [1, 2, 3] :: Int3>>>genericLength [1, 2, 3] :: Float3.0
genericDrop :: Integral i => i -> [a] -> [a] #
The genericDrop function is an overloaded version of drop, which
accepts any Integral value as the number of elements to drop.
Maybe monoid returning the rightmost non-Nothing value.
Last aDual (First a)Dual (Alt Maybe a)
>>>getLast (Last (Just "hello") <> Last Nothing <> Last (Just "world"))Just "world"
Instances
| FromJSON1 Last | |
| ToJSON1 Last | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Last a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Last a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Last a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Last a] -> Encoding # | |
| MonadFix Last | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable Last | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Last m -> m # foldMap :: Monoid m => (a -> m) -> Last a -> m # foldMap' :: Monoid m => (a -> m) -> Last a -> m # foldr :: (a -> b -> b) -> b -> Last a -> b # foldr' :: (a -> b -> b) -> b -> Last a -> b # foldl :: (b -> a -> b) -> b -> Last a -> b # foldl' :: (b -> a -> b) -> b -> Last a -> b # foldr1 :: (a -> a -> a) -> Last a -> a # foldl1 :: (a -> a -> a) -> Last a -> a # elem :: Eq a => a -> Last a -> Bool # maximum :: Ord a => Last a -> a # | |
| Traversable Last | Since: base-4.8.0.0 |
| Applicative Last | Since: base-4.8.0.0 |
| Functor Last | Since: base-4.8.0.0 |
| Monad Last | Since: base-4.8.0.0 |
| NFData1 Last | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| FromJSON a => FromJSON (Last a) | |
| ToJSON a => ToJSON (Last a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Last a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Last a -> c (Last a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Last a) # toConstr :: Last a -> Constr # dataTypeOf :: Last a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Last a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Last a)) # gmapT :: (forall b. Data b => b -> b) -> Last a -> Last a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Last a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Last a -> r # gmapQ :: (forall d. Data d => d -> u) -> Last a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Last a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Last a -> m (Last a) # | |
| Monoid (Last a) | Since: base-2.1 |
| Semigroup (Last a) | Since: base-4.9.0.0 |
| Generic (Last a) | |
| Read a => Read (Last a) | Since: base-2.1 |
| Show a => Show (Last a) | Since: base-2.1 |
| Binary a => Binary (Last a) | Since: binary-0.8.4.0 |
| NFData a => NFData (Last a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Last a) | Since: base-2.1 |
| Ord a => Ord (Last a) | Since: base-2.1 |
| Serialise a => Serialise (Last a) | Since: serialise-0.2.0.0 |
| Generic1 Last | |
| type Rep (Last a) | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
| type Rep1 Last | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
Maybe monoid returning the leftmost non-Nothing value.
First aAlt Maybe a
>>>getFirst (First (Just "hello") <> First Nothing <> First (Just "world"))Just "hello"
Instances
| FromJSON1 First | |
| ToJSON1 First | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> First a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [First a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> First a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [First a] -> Encoding # | |
| MonadFix First | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable First | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => First m -> m # foldMap :: Monoid m => (a -> m) -> First a -> m # foldMap' :: Monoid m => (a -> m) -> First a -> m # foldr :: (a -> b -> b) -> b -> First a -> b # foldr' :: (a -> b -> b) -> b -> First a -> b # foldl :: (b -> a -> b) -> b -> First a -> b # foldl' :: (b -> a -> b) -> b -> First a -> b # foldr1 :: (a -> a -> a) -> First a -> a # foldl1 :: (a -> a -> a) -> First a -> a # elem :: Eq a => a -> First a -> Bool # maximum :: Ord a => First a -> a # minimum :: Ord a => First a -> a # | |
| Traversable First | Since: base-4.8.0.0 |
| Applicative First | Since: base-4.8.0.0 |
| Functor First | Since: base-4.8.0.0 |
| Monad First | Since: base-4.8.0.0 |
| NFData1 First | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| FromJSON a => FromJSON (First a) | |
| ToJSON a => ToJSON (First a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (First a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> First a -> c (First a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (First a) # toConstr :: First a -> Constr # dataTypeOf :: First a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (First a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (First a)) # gmapT :: (forall b. Data b => b -> b) -> First a -> First a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> First a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> First a -> r # gmapQ :: (forall d. Data d => d -> u) -> First a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> First a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> First a -> m (First a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> First a -> m (First a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> First a -> m (First a) # | |
| Monoid (First a) | Since: base-2.1 |
| Semigroup (First a) | Since: base-4.9.0.0 |
| Generic (First a) | |
| Read a => Read (First a) | Since: base-2.1 |
| Show a => Show (First a) | Since: base-2.1 |
| Binary a => Binary (First a) | Since: binary-0.8.4.0 |
| NFData a => NFData (First a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (First a) | Since: base-2.1 |
| Ord a => Ord (First a) | Since: base-2.1 |
| Serialise a => Serialise (First a) | Since: serialise-0.2.0.0 |
| Generic1 First | |
| type Rep (First a) | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
| type Rep1 First | Since: base-4.7.0.0 |
Defined in Data.Monoid | |
newtype Ap (f :: k -> Type) (a :: k) #
This data type witnesses the lifting of a Monoid into an
Applicative pointwise.
Since: base-4.12.0.0
Instances
| Generic1 (Ap f :: k -> Type) | |
| MonadFail f => MonadFail (Ap f) | Since: base-4.12.0.0 |
Defined in Data.Monoid | |
| MonadFix f => MonadFix (Ap f) | Since: base-4.12.0.0 |
Defined in Control.Monad.Fix | |
| Foldable f => Foldable (Ap f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Ap f m -> m # foldMap :: Monoid m => (a -> m) -> Ap f a -> m # foldMap' :: Monoid m => (a -> m) -> Ap f a -> m # foldr :: (a -> b -> b) -> b -> Ap f a -> b # foldr' :: (a -> b -> b) -> b -> Ap f a -> b # foldl :: (b -> a -> b) -> b -> Ap f a -> b # foldl' :: (b -> a -> b) -> b -> Ap f a -> b # foldr1 :: (a -> a -> a) -> Ap f a -> a # foldl1 :: (a -> a -> a) -> Ap f a -> a # elem :: Eq a => a -> Ap f a -> Bool # maximum :: Ord a => Ap f a -> a # | |
| Traversable f => Traversable (Ap f) | Since: base-4.12.0.0 |
| Alternative f => Alternative (Ap f) | Since: base-4.12.0.0 |
| Applicative f => Applicative (Ap f) | Since: base-4.12.0.0 |
| Functor f => Functor (Ap f) | Since: base-4.12.0.0 |
| Monad f => Monad (Ap f) | Since: base-4.12.0.0 |
| MonadPlus f => MonadPlus (Ap f) | Since: base-4.12.0.0 |
| (Data (f a), Data a, Typeable f) => Data (Ap f a) | Since: base-4.12.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Ap f a -> c (Ap f a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Ap f a) # toConstr :: Ap f a -> Constr # dataTypeOf :: Ap f a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Ap f a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Ap f a)) # gmapT :: (forall b. Data b => b -> b) -> Ap f a -> Ap f a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ap f a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ap f a -> r # gmapQ :: (forall d. Data d => d -> u) -> Ap f a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Ap f a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ap f a -> m (Ap f a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ap f a -> m (Ap f a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ap f a -> m (Ap f a) # | |
| (Applicative f, Monoid a) => Monoid (Ap f a) | Since: base-4.12.0.0 |
| (Applicative f, Semigroup a) => Semigroup (Ap f a) | Since: base-4.12.0.0 |
| (Applicative f, Bounded a) => Bounded (Ap f a) | Since: base-4.12.0.0 |
| Enum (f a) => Enum (Ap f a) | Since: base-4.12.0.0 |
Defined in Data.Monoid | |
| Generic (Ap f a) | |
| (Applicative f, Num a) => Num (Ap f a) | Note that even if the underlying Commutativity:
Additive inverse:
Distributivity:
Since: base-4.12.0.0 |
| Read (f a) => Read (Ap f a) | Since: base-4.12.0.0 |
| Show (f a) => Show (Ap f a) | Since: base-4.12.0.0 |
| Eq (f a) => Eq (Ap f a) | Since: base-4.12.0.0 |
| Ord (f a) => Ord (Ap f a) | Since: base-4.12.0.0 |
| type Rep1 (Ap f :: k -> Type) | Since: base-4.12.0.0 |
Defined in Data.Monoid | |
| type Rep (Ap f a) | Since: base-4.12.0.0 |
Defined in Data.Monoid | |
Monoid under addition.
>>>getSum (Sum 1 <> Sum 2 <> mempty)3
Instances
| MonadFix Sum | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable Sum | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Sum m -> m # foldMap :: Monoid m => (a -> m) -> Sum a -> m # foldMap' :: Monoid m => (a -> m) -> Sum a -> m # foldr :: (a -> b -> b) -> b -> Sum a -> b # foldr' :: (a -> b -> b) -> b -> Sum a -> b # foldl :: (b -> a -> b) -> b -> Sum a -> b # foldl' :: (b -> a -> b) -> b -> Sum a -> b # foldr1 :: (a -> a -> a) -> Sum a -> a # foldl1 :: (a -> a -> a) -> Sum a -> a # elem :: Eq a => a -> Sum a -> Bool # maximum :: Ord a => Sum a -> a # | |
| Traversable Sum | Since: base-4.8.0.0 |
| Applicative Sum | Since: base-4.8.0.0 |
| Functor Sum | Since: base-4.8.0.0 |
| Monad Sum | Since: base-4.8.0.0 |
| NFData1 Sum | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Unbox a => Vector Vector (Sum a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Sum a) -> ST s (Vector (Sum a)) # basicUnsafeThaw :: Vector (Sum a) -> ST s (Mutable Vector s (Sum a)) # basicLength :: Vector (Sum a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Sum a) -> Vector (Sum a) # basicUnsafeIndexM :: Vector (Sum a) -> Int -> Box (Sum a) # basicUnsafeCopy :: Mutable Vector s (Sum a) -> Vector (Sum a) -> ST s () # | |
| Unbox a => MVector MVector (Sum a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Sum a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Sum a) -> MVector s (Sum a) # basicOverlaps :: MVector s (Sum a) -> MVector s (Sum a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Sum a)) # basicInitialize :: MVector s (Sum a) -> ST s () # basicUnsafeReplicate :: Int -> Sum a -> ST s (MVector s (Sum a)) # basicUnsafeRead :: MVector s (Sum a) -> Int -> ST s (Sum a) # basicUnsafeWrite :: MVector s (Sum a) -> Int -> Sum a -> ST s () # basicClear :: MVector s (Sum a) -> ST s () # basicSet :: MVector s (Sum a) -> Sum a -> ST s () # basicUnsafeCopy :: MVector s (Sum a) -> MVector s (Sum a) -> ST s () # basicUnsafeMove :: MVector s (Sum a) -> MVector s (Sum a) -> ST s () # basicUnsafeGrow :: MVector s (Sum a) -> Int -> ST s (MVector s (Sum a)) # | |
| Data a => Data (Sum a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Sum a -> c (Sum a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Sum a) # dataTypeOf :: Sum a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Sum a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Sum a)) # gmapT :: (forall b. Data b => b -> b) -> Sum a -> Sum a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Sum a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Sum a -> r # gmapQ :: (forall d. Data d => d -> u) -> Sum a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Sum a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Sum a -> m (Sum a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Sum a -> m (Sum a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Sum a -> m (Sum a) # | |
| Num a => Monoid (Sum a) | Since: base-2.1 |
| Num a => Semigroup (Sum a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Sum a) | Since: base-2.1 |
| Generic (Sum a) | |
| Num a => Num (Sum a) | Since: base-4.7.0.0 |
| Read a => Read (Sum a) | Since: base-2.1 |
| Show a => Show (Sum a) | Since: base-2.1 |
| Binary a => Binary (Sum a) | Since: binary-0.8.4.0 |
| NFData a => NFData (Sum a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Sum a) | Since: base-2.1 |
| Ord a => Ord (Sum a) | Since: base-2.1 |
| Prim a => Prim (Sum a) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods alignment# :: Sum a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Sum a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Sum a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Sum a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Sum a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Sum a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Sum a #) # writeOffAddr# :: Addr# -> Int# -> Sum a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Sum a -> State# s -> State# s # | |
| Serialise a => Serialise (Sum a) | Since: serialise-0.2.0.0 |
| Unbox a => Unbox (Sum a) | |
Defined in Data.Vector.Unboxed.Base | |
| Generic1 Sum | |
| newtype MVector s (Sum a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Sum a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector (Sum a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 Sum | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
Monoid under multiplication.
>>>getProduct (Product 3 <> Product 4 <> mempty)12
Constructors
| Product | |
Fields
| |
Instances
| MonadFix Product | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable Product | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Product m -> m # foldMap :: Monoid m => (a -> m) -> Product a -> m # foldMap' :: Monoid m => (a -> m) -> Product a -> m # foldr :: (a -> b -> b) -> b -> Product a -> b # foldr' :: (a -> b -> b) -> b -> Product a -> b # foldl :: (b -> a -> b) -> b -> Product a -> b # foldl' :: (b -> a -> b) -> b -> Product a -> b # foldr1 :: (a -> a -> a) -> Product a -> a # foldl1 :: (a -> a -> a) -> Product a -> a # elem :: Eq a => a -> Product a -> Bool # maximum :: Ord a => Product a -> a # minimum :: Ord a => Product a -> a # | |
| Traversable Product | Since: base-4.8.0.0 |
| Applicative Product | Since: base-4.8.0.0 |
| Functor Product | Since: base-4.8.0.0 |
| Monad Product | Since: base-4.8.0.0 |
| NFData1 Product | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Unbox a => Vector Vector (Product a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Product a) -> ST s (Vector (Product a)) # basicUnsafeThaw :: Vector (Product a) -> ST s (Mutable Vector s (Product a)) # basicLength :: Vector (Product a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Product a) -> Vector (Product a) # basicUnsafeIndexM :: Vector (Product a) -> Int -> Box (Product a) # basicUnsafeCopy :: Mutable Vector s (Product a) -> Vector (Product a) -> ST s () # | |
| Unbox a => MVector MVector (Product a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Product a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Product a) -> MVector s (Product a) # basicOverlaps :: MVector s (Product a) -> MVector s (Product a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Product a)) # basicInitialize :: MVector s (Product a) -> ST s () # basicUnsafeReplicate :: Int -> Product a -> ST s (MVector s (Product a)) # basicUnsafeRead :: MVector s (Product a) -> Int -> ST s (Product a) # basicUnsafeWrite :: MVector s (Product a) -> Int -> Product a -> ST s () # basicClear :: MVector s (Product a) -> ST s () # basicSet :: MVector s (Product a) -> Product a -> ST s () # basicUnsafeCopy :: MVector s (Product a) -> MVector s (Product a) -> ST s () # basicUnsafeMove :: MVector s (Product a) -> MVector s (Product a) -> ST s () # basicUnsafeGrow :: MVector s (Product a) -> Int -> ST s (MVector s (Product a)) # | |
| Data a => Data (Product a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Product a -> c (Product a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Product a) # toConstr :: Product a -> Constr # dataTypeOf :: Product a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Product a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Product a)) # gmapT :: (forall b. Data b => b -> b) -> Product a -> Product a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Product a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Product a -> r # gmapQ :: (forall d. Data d => d -> u) -> Product a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Product a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Product a -> m (Product a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Product a -> m (Product a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Product a -> m (Product a) # | |
| Num a => Monoid (Product a) | Since: base-2.1 |
| Num a => Semigroup (Product a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Product a) | Since: base-2.1 |
| Generic (Product a) | |
| Num a => Num (Product a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| Read a => Read (Product a) | Since: base-2.1 |
| Show a => Show (Product a) | Since: base-2.1 |
| Binary a => Binary (Product a) | Since: binary-0.8.4.0 |
| NFData a => NFData (Product a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Product a) | Since: base-2.1 |
| Ord a => Ord (Product a) | Since: base-2.1 |
| Prim a => Prim (Product a) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods sizeOf# :: Product a -> Int# # alignment# :: Product a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Product a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Product a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Product a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Product a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Product a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Product a #) # writeOffAddr# :: Addr# -> Int# -> Product a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Product a -> State# s -> State# s # | |
| Serialise a => Serialise (Product a) | Since: serialise-0.2.0.0 |
| Unbox a => Unbox (Product a) | |
Defined in Data.Vector.Unboxed.Base | |
| Generic1 Product | |
| newtype MVector s (Product a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Product a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector (Product a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 Product | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
The monoid of endomorphisms under composition.
>>>let computation = Endo ("Hello, " ++) <> Endo (++ "!")>>>appEndo computation "Haskell""Hello, Haskell!"
The dual of a Monoid, obtained by swapping the arguments of mappend.
>>>getDual (mappend (Dual "Hello") (Dual "World"))"WorldHello"
Instances
| FromJSON1 Dual | |
| ToJSON1 Dual | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Dual a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Dual a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Dual a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Dual a] -> Encoding # | |
| MonadFix Dual | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable Dual | Since: base-4.8.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Dual m -> m # foldMap :: Monoid m => (a -> m) -> Dual a -> m # foldMap' :: Monoid m => (a -> m) -> Dual a -> m # foldr :: (a -> b -> b) -> b -> Dual a -> b # foldr' :: (a -> b -> b) -> b -> Dual a -> b # foldl :: (b -> a -> b) -> b -> Dual a -> b # foldl' :: (b -> a -> b) -> b -> Dual a -> b # foldr1 :: (a -> a -> a) -> Dual a -> a # foldl1 :: (a -> a -> a) -> Dual a -> a # elem :: Eq a => a -> Dual a -> Bool # maximum :: Ord a => Dual a -> a # | |
| Traversable Dual | Since: base-4.8.0.0 |
| Applicative Dual | Since: base-4.8.0.0 |
| Functor Dual | Since: base-4.8.0.0 |
| Monad Dual | Since: base-4.8.0.0 |
| NFData1 Dual | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Unbox a => Vector Vector (Dual a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Dual a) -> ST s (Vector (Dual a)) # basicUnsafeThaw :: Vector (Dual a) -> ST s (Mutable Vector s (Dual a)) # basicLength :: Vector (Dual a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Dual a) -> Vector (Dual a) # basicUnsafeIndexM :: Vector (Dual a) -> Int -> Box (Dual a) # basicUnsafeCopy :: Mutable Vector s (Dual a) -> Vector (Dual a) -> ST s () # | |
| Unbox a => MVector MVector (Dual a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Dual a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Dual a) -> MVector s (Dual a) # basicOverlaps :: MVector s (Dual a) -> MVector s (Dual a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Dual a)) # basicInitialize :: MVector s (Dual a) -> ST s () # basicUnsafeReplicate :: Int -> Dual a -> ST s (MVector s (Dual a)) # basicUnsafeRead :: MVector s (Dual a) -> Int -> ST s (Dual a) # basicUnsafeWrite :: MVector s (Dual a) -> Int -> Dual a -> ST s () # basicClear :: MVector s (Dual a) -> ST s () # basicSet :: MVector s (Dual a) -> Dual a -> ST s () # basicUnsafeCopy :: MVector s (Dual a) -> MVector s (Dual a) -> ST s () # basicUnsafeMove :: MVector s (Dual a) -> MVector s (Dual a) -> ST s () # basicUnsafeGrow :: MVector s (Dual a) -> Int -> ST s (MVector s (Dual a)) # | |
| FromJSON a => FromJSON (Dual a) | |
| ToJSON a => ToJSON (Dual a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Dual a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Dual a -> c (Dual a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Dual a) # toConstr :: Dual a -> Constr # dataTypeOf :: Dual a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Dual a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Dual a)) # gmapT :: (forall b. Data b => b -> b) -> Dual a -> Dual a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Dual a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Dual a -> r # gmapQ :: (forall d. Data d => d -> u) -> Dual a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Dual a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Dual a -> m (Dual a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Dual a -> m (Dual a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Dual a -> m (Dual a) # | |
| Monoid a => Monoid (Dual a) | Since: base-2.1 |
| Semigroup a => Semigroup (Dual a) | Since: base-4.9.0.0 |
| Bounded a => Bounded (Dual a) | Since: base-2.1 |
| Generic (Dual a) | |
| Read a => Read (Dual a) | Since: base-2.1 |
| Show a => Show (Dual a) | Since: base-2.1 |
| Binary a => Binary (Dual a) | Since: binary-0.8.4.0 |
| NFData a => NFData (Dual a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Dual a) | Since: base-2.1 |
| Ord a => Ord (Dual a) | Since: base-2.1 |
| Prim a => Prim (Dual a) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods alignment# :: Dual a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Dual a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Dual a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Dual a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Dual a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Dual a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Dual a #) # writeOffAddr# :: Addr# -> Int# -> Dual a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Dual a -> State# s -> State# s # | |
| Serialise a => Serialise (Dual a) | Since: serialise-0.2.0.0 |
| Unbox a => Unbox (Dual a) | |
Defined in Data.Vector.Unboxed.Base | |
| Generic1 Dual | |
| newtype MVector s (Dual a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Dual a) | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector (Dual a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 Dual | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
Boolean monoid under disjunction (||).
>>>getAny (Any True <> mempty <> Any False)True
>>>getAny (mconcat (map (\x -> Any (even x)) [2,4,6,7,8]))True
Instances
| Dioid Any | |
Defined in Algebra.Graph.Label | |
| Semiring Any | |
| StarSemiring Any | |
Defined in Algebra.Graph.Label | |
| Data Any | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Any -> c Any # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Any # dataTypeOf :: Any -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Any) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Any) # gmapT :: (forall b. Data b => b -> b) -> Any -> Any # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Any -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Any -> r # gmapQ :: (forall d. Data d => d -> u) -> Any -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Any -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Any -> m Any # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Any -> m Any # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Any -> m Any # | |
| Monoid Any | Since: base-2.1 |
| Semigroup Any | Since: base-4.9.0.0 |
| Bounded Any | Since: base-2.1 |
| Generic Any | |
| Read Any | Since: base-2.1 |
| Show Any | Since: base-2.1 |
| Binary Any | Since: binary-0.8.4.0 |
| NFData Any | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq Any | Since: base-2.1 |
| Ord Any | Since: base-2.1 |
| Serialise Any | Since: serialise-0.2.0.0 |
| Unbox Any | |
Defined in Data.Vector.Unboxed.Base | |
| Vector Vector Any | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s Any -> ST s (Vector Any) # basicUnsafeThaw :: Vector Any -> ST s (Mutable Vector s Any) # basicLength :: Vector Any -> Int # basicUnsafeSlice :: Int -> Int -> Vector Any -> Vector Any # basicUnsafeIndexM :: Vector Any -> Int -> Box Any # basicUnsafeCopy :: Mutable Vector s Any -> Vector Any -> ST s () # | |
| MVector MVector Any | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s Any -> Int # basicUnsafeSlice :: Int -> Int -> MVector s Any -> MVector s Any # basicOverlaps :: MVector s Any -> MVector s Any -> Bool # basicUnsafeNew :: Int -> ST s (MVector s Any) # basicInitialize :: MVector s Any -> ST s () # basicUnsafeReplicate :: Int -> Any -> ST s (MVector s Any) # basicUnsafeRead :: MVector s Any -> Int -> ST s Any # basicUnsafeWrite :: MVector s Any -> Int -> Any -> ST s () # basicClear :: MVector s Any -> ST s () # basicSet :: MVector s Any -> Any -> ST s () # basicUnsafeCopy :: MVector s Any -> MVector s Any -> ST s () # basicUnsafeMove :: MVector s Any -> MVector s Any -> ST s () # basicUnsafeGrow :: MVector s Any -> Int -> ST s (MVector s Any) # | |
| type Rep Any | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector Any | |
| newtype MVector s Any | |
newtype Alt (f :: k -> Type) (a :: k) #
Monoid under <|>.
>>>getAlt (Alt (Just 12) <> Alt (Just 24))Just 12
>>>getAlt $ Alt Nothing <> Alt (Just 24)Just 24
Since: base-4.8.0.0
Instances
| Generic1 (Alt f :: k -> Type) | |
| Unbox (f a) => Vector Vector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Alt f a) -> ST s (Vector (Alt f a)) # basicUnsafeThaw :: Vector (Alt f a) -> ST s (Mutable Vector s (Alt f a)) # basicLength :: Vector (Alt f a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Alt f a) -> Vector (Alt f a) # basicUnsafeIndexM :: Vector (Alt f a) -> Int -> Box (Alt f a) # basicUnsafeCopy :: Mutable Vector s (Alt f a) -> Vector (Alt f a) -> ST s () # | |
| Unbox (f a) => MVector MVector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Alt f a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Alt f a) -> MVector s (Alt f a) # basicOverlaps :: MVector s (Alt f a) -> MVector s (Alt f a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Alt f a)) # basicInitialize :: MVector s (Alt f a) -> ST s () # basicUnsafeReplicate :: Int -> Alt f a -> ST s (MVector s (Alt f a)) # basicUnsafeRead :: MVector s (Alt f a) -> Int -> ST s (Alt f a) # basicUnsafeWrite :: MVector s (Alt f a) -> Int -> Alt f a -> ST s () # basicClear :: MVector s (Alt f a) -> ST s () # basicSet :: MVector s (Alt f a) -> Alt f a -> ST s () # basicUnsafeCopy :: MVector s (Alt f a) -> MVector s (Alt f a) -> ST s () # basicUnsafeMove :: MVector s (Alt f a) -> MVector s (Alt f a) -> ST s () # basicUnsafeGrow :: MVector s (Alt f a) -> Int -> ST s (MVector s (Alt f a)) # | |
| MonadFix f => MonadFix (Alt f) | Since: base-4.8.0.0 |
Defined in Control.Monad.Fix | |
| Foldable f => Foldable (Alt f) | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Alt f m -> m # foldMap :: Monoid m => (a -> m) -> Alt f a -> m # foldMap' :: Monoid m => (a -> m) -> Alt f a -> m # foldr :: (a -> b -> b) -> b -> Alt f a -> b # foldr' :: (a -> b -> b) -> b -> Alt f a -> b # foldl :: (b -> a -> b) -> b -> Alt f a -> b # foldl' :: (b -> a -> b) -> b -> Alt f a -> b # foldr1 :: (a -> a -> a) -> Alt f a -> a # foldl1 :: (a -> a -> a) -> Alt f a -> a # elem :: Eq a => a -> Alt f a -> Bool # maximum :: Ord a => Alt f a -> a # minimum :: Ord a => Alt f a -> a # | |
| Contravariant f => Contravariant (Alt f) | |
| Traversable f => Traversable (Alt f) | Since: base-4.12.0.0 |
| Alternative f => Alternative (Alt f) | Since: base-4.8.0.0 |
| Applicative f => Applicative (Alt f) | Since: base-4.8.0.0 |
| Functor f => Functor (Alt f) | Since: base-4.8.0.0 |
| Monad f => Monad (Alt f) | Since: base-4.8.0.0 |
| MonadPlus f => MonadPlus (Alt f) | Since: base-4.8.0.0 |
| (Data (f a), Data a, Typeable f) => Data (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Alt f a -> c (Alt f a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Alt f a) # toConstr :: Alt f a -> Constr # dataTypeOf :: Alt f a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Alt f a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Alt f a)) # gmapT :: (forall b. Data b => b -> b) -> Alt f a -> Alt f a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Alt f a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Alt f a -> r # gmapQ :: (forall d. Data d => d -> u) -> Alt f a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Alt f a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Alt f a -> m (Alt f a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Alt f a -> m (Alt f a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Alt f a -> m (Alt f a) # | |
| Alternative f => Monoid (Alt f a) | Since: base-4.8.0.0 |
| Alternative f => Semigroup (Alt f a) | Since: base-4.9.0.0 |
| Enum (f a) => Enum (Alt f a) | Since: base-4.8.0.0 |
| Generic (Alt f a) | |
| Num (f a) => Num (Alt f a) | Since: base-4.8.0.0 |
| Read (f a) => Read (Alt f a) | Since: base-4.8.0.0 |
| Show (f a) => Show (Alt f a) | Since: base-4.8.0.0 |
| Binary (f a) => Binary (Alt f a) | Since: binary-0.8.4.0 |
| Eq (f a) => Eq (Alt f a) | Since: base-4.8.0.0 |
| Ord (f a) => Ord (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| Serialise (f a) => Serialise (Alt f a) | Since: serialise-0.2.0.0 |
| Unbox (f a) => Unbox (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 (Alt f :: k -> Type) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype MVector s (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Alt f a) | Since: base-4.8.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector (Alt f a) | |
Defined in Data.Vector.Unboxed.Base | |
Boolean monoid under conjunction (&&).
>>>getAll (All True <> mempty <> All False)False
>>>getAll (mconcat (map (\x -> All (even x)) [2,4,6,7,8]))False
Instances
| Data All | Since: base-4.8.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> All -> c All # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c All # dataTypeOf :: All -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c All) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c All) # gmapT :: (forall b. Data b => b -> b) -> All -> All # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> All -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> All -> r # gmapQ :: (forall d. Data d => d -> u) -> All -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> All -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> All -> m All # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> All -> m All # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> All -> m All # | |
| Monoid All | Since: base-2.1 |
| Semigroup All | Since: base-4.9.0.0 |
| Bounded All | Since: base-2.1 |
| Generic All | |
| Read All | Since: base-2.1 |
| Show All | Since: base-2.1 |
| Binary All | Since: binary-0.8.4.0 |
| NFData All | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq All | Since: base-2.1 |
| Ord All | Since: base-2.1 |
| Serialise All | Since: serialise-0.2.0.0 |
| Unbox All | |
Defined in Data.Vector.Unboxed.Base | |
| Vector Vector All | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s All -> ST s (Vector All) # basicUnsafeThaw :: Vector All -> ST s (Mutable Vector s All) # basicLength :: Vector All -> Int # basicUnsafeSlice :: Int -> Int -> Vector All -> Vector All # basicUnsafeIndexM :: Vector All -> Int -> Box All # basicUnsafeCopy :: Mutable Vector s All -> Vector All -> ST s () # | |
| MVector MVector All | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s All -> Int # basicUnsafeSlice :: Int -> Int -> MVector s All -> MVector s All # basicOverlaps :: MVector s All -> MVector s All -> Bool # basicUnsafeNew :: Int -> ST s (MVector s All) # basicInitialize :: MVector s All -> ST s () # basicUnsafeReplicate :: Int -> All -> ST s (MVector s All) # basicUnsafeRead :: MVector s All -> Int -> ST s All # basicUnsafeWrite :: MVector s All -> Int -> All -> ST s () # basicClear :: MVector s All -> ST s () # basicSet :: MVector s All -> All -> ST s () # basicUnsafeCopy :: MVector s All -> MVector s All -> ST s () # basicUnsafeMove :: MVector s All -> MVector s All -> ST s () # basicUnsafeGrow :: MVector s All -> Int -> ST s (MVector s All) # | |
| type Rep All | Since: base-4.7.0.0 |
Defined in Data.Semigroup.Internal | |
| newtype Vector All | |
| newtype MVector s All | |
stimesMonoid :: (Integral b, Monoid a) => b -> a -> a #
stimesIdempotent :: Integral b => b -> a -> a #
This type represents unknown type-level natural numbers.
Since: base-4.10.0.0
A type synonym for Natural.
Prevously, this was an opaque data type, but it was changed to a type synonym.
Since: base-4.16.0.0
someNatVal :: Natural -> SomeNat #
Convert an integer into an unknown type-level natural.
Since: base-4.10.0.0
The Down type allows you to reverse sort order conveniently. A value of type
Down aa (represented as Down a
If a has an Ordthen sortWith by .Down x
>>>compare True FalseGT
>>>compare (Down True) (Down False)LT
If a has a BoundedminBoundmaxBound
>>>minBound :: Int-9223372036854775808
>>>minBound :: Down IntDown 9223372036854775807
All other instances of Down aa.
Since: base-4.6.0.0
Instances
| MonadFix Down | Since: base-4.12.0.0 |
Defined in Control.Monad.Fix | |
| Foldable Down | Since: base-4.12.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Down m -> m # foldMap :: Monoid m => (a -> m) -> Down a -> m # foldMap' :: Monoid m => (a -> m) -> Down a -> m # foldr :: (a -> b -> b) -> b -> Down a -> b # foldr' :: (a -> b -> b) -> b -> Down a -> b # foldl :: (b -> a -> b) -> b -> Down a -> b # foldl' :: (b -> a -> b) -> b -> Down a -> b # foldr1 :: (a -> a -> a) -> Down a -> a # foldl1 :: (a -> a -> a) -> Down a -> a # elem :: Eq a => a -> Down a -> Bool # maximum :: Ord a => Down a -> a # | |
| Eq1 Down | Since: base-4.12.0.0 |
| Ord1 Down | Since: base-4.12.0.0 |
Defined in Data.Functor.Classes | |
| Read1 Down | Since: base-4.12.0.0 |
Defined in Data.Functor.Classes | |
| Show1 Down | Since: base-4.12.0.0 |
| Traversable Down | Since: base-4.12.0.0 |
| Applicative Down | Since: base-4.11.0.0 |
| Functor Down | Since: base-4.11.0.0 |
| Monad Down | Since: base-4.11.0.0 |
| NFData1 Down | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Generic1 Down | |
| Unbox a => Vector Vector (Down a) | |
Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: Mutable Vector s (Down a) -> ST s (Vector (Down a)) # basicUnsafeThaw :: Vector (Down a) -> ST s (Mutable Vector s (Down a)) # basicLength :: Vector (Down a) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Down a) -> Vector (Down a) # basicUnsafeIndexM :: Vector (Down a) -> Int -> Box (Down a) # basicUnsafeCopy :: Mutable Vector s (Down a) -> Vector (Down a) -> ST s () # | |
| Unbox a => MVector MVector (Down a) | |
Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Down a) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Down a) -> MVector s (Down a) # basicOverlaps :: MVector s (Down a) -> MVector s (Down a) -> Bool # basicUnsafeNew :: Int -> ST s (MVector s (Down a)) # basicInitialize :: MVector s (Down a) -> ST s () # basicUnsafeReplicate :: Int -> Down a -> ST s (MVector s (Down a)) # basicUnsafeRead :: MVector s (Down a) -> Int -> ST s (Down a) # basicUnsafeWrite :: MVector s (Down a) -> Int -> Down a -> ST s () # basicClear :: MVector s (Down a) -> ST s () # basicSet :: MVector s (Down a) -> Down a -> ST s () # basicUnsafeCopy :: MVector s (Down a) -> MVector s (Down a) -> ST s () # basicUnsafeMove :: MVector s (Down a) -> MVector s (Down a) -> ST s () # basicUnsafeGrow :: MVector s (Down a) -> Int -> ST s (MVector s (Down a)) # | |
| Data a => Data (Down a) | Since: base-4.12.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Down a -> c (Down a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Down a) # toConstr :: Down a -> Constr # dataTypeOf :: Down a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Down a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Down a)) # gmapT :: (forall b. Data b => b -> b) -> Down a -> Down a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Down a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Down a -> r # gmapQ :: (forall d. Data d => d -> u) -> Down a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Down a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Down a -> m (Down a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Down a -> m (Down a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Down a -> m (Down a) # | |
| Storable a => Storable (Down a) | Since: base-4.14.0.0 |
| Monoid a => Monoid (Down a) | Since: base-4.11.0.0 |
| Semigroup a => Semigroup (Down a) | Since: base-4.11.0.0 |
| Bits a => Bits (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods (.&.) :: Down a -> Down a -> Down a # (.|.) :: Down a -> Down a -> Down a # xor :: Down a -> Down a -> Down a # complement :: Down a -> Down a # shift :: Down a -> Int -> Down a # rotate :: Down a -> Int -> Down a # setBit :: Down a -> Int -> Down a # clearBit :: Down a -> Int -> Down a # complementBit :: Down a -> Int -> Down a # testBit :: Down a -> Int -> Bool # bitSizeMaybe :: Down a -> Maybe Int # shiftL :: Down a -> Int -> Down a # unsafeShiftL :: Down a -> Int -> Down a # shiftR :: Down a -> Int -> Down a # unsafeShiftR :: Down a -> Int -> Down a # rotateL :: Down a -> Int -> Down a # | |
| FiniteBits a => FiniteBits (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods finiteBitSize :: Down a -> Int # countLeadingZeros :: Down a -> Int # countTrailingZeros :: Down a -> Int # | |
| Bounded a => Bounded (Down a) | Swaps Since: base-4.14.0.0 |
| Floating a => Floating (Down a) | Since: base-4.14.0.0 |
| RealFloat a => RealFloat (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods floatRadix :: Down a -> Integer # floatDigits :: Down a -> Int # floatRange :: Down a -> (Int, Int) # decodeFloat :: Down a -> (Integer, Int) # encodeFloat :: Integer -> Int -> Down a # significand :: Down a -> Down a # scaleFloat :: Int -> Down a -> Down a # isInfinite :: Down a -> Bool # isDenormalized :: Down a -> Bool # isNegativeZero :: Down a -> Bool # | |
| Generic (Down a) | |
| Ix a => Ix (Down a) | Since: base-4.14.0.0 |
| Num a => Num (Down a) | Since: base-4.11.0.0 |
| Read a => Read (Down a) | This instance would be equivalent to the derived instances of the
Since: base-4.7.0.0 |
| Fractional a => Fractional (Down a) | Since: base-4.14.0.0 |
| Real a => Real (Down a) | Since: base-4.14.0.0 |
Defined in Data.Ord Methods toRational :: Down a -> Rational # | |
| RealFrac a => RealFrac (Down a) | Since: base-4.14.0.0 |
| Show a => Show (Down a) | This instance would be equivalent to the derived instances of the
Since: base-4.7.0.0 |
| NFData a => NFData (Down a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq a => Eq (Down a) | Since: base-4.6.0.0 |
| Ord a => Ord (Down a) | Since: base-4.6.0.0 |
| Prim a => Prim (Down a) | Since: primitive-0.6.5.0 |
Defined in Data.Primitive.Types Methods alignment# :: Down a -> Int# # indexByteArray# :: ByteArray# -> Int# -> Down a # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Down a #) # writeByteArray# :: MutableByteArray# s -> Int# -> Down a -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Down a -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Down a # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Down a #) # writeOffAddr# :: Addr# -> Int# -> Down a -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Down a -> State# s -> State# s # | |
| Serialise a => Serialise (Down a) | Since: serialise-0.2.0.0 |
| Unbox a => Unbox (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep1 Down | Since: base-4.12.0.0 |
Defined in GHC.Generics | |
| newtype MVector s (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
| type Rep (Down a) | Since: base-4.12.0.0 |
Defined in GHC.Generics | |
| newtype Vector (Down a) | |
Defined in Data.Vector.Unboxed.Base | |
comparing :: Ord a => (b -> a) -> b -> b -> Ordering #
comparing p x y = compare (p x) (p y)
Useful combinator for use in conjunction with the xxxBy family
of functions from Data.List, for example:
... sortBy (comparing fst) ...
readMaybe :: Read a => String -> Maybe a #
Parse a string using the Read instance.
Succeeds if there is exactly one valid result.
>>>readMaybe "123" :: Maybe IntJust 123
>>>readMaybe "hello" :: Maybe IntNothing
Since: base-4.6.0.0
isLeft :: Either a b -> Bool #
Return True if the given value is a Left-value, False otherwise.
Examples
Basic usage:
>>>isLeft (Left "foo")True>>>isLeft (Right 3)False
Assuming a Left value signifies some sort of error, we can use
isLeft to write a very simple error-reporting function that does
absolutely nothing in the case of success, and outputs "ERROR" if
any error occurred.
This example shows how isLeft might be used to avoid pattern
matching when one does not care about the value contained in the
constructor:
>>>import Control.Monad ( when )>>>let report e = when (isLeft e) $ putStrLn "ERROR">>>report (Right 1)>>>report (Left "parse error")ERROR
Since: base-4.7.0.0
fromRight :: b -> Either a b -> b #
Return the contents of a Right-value or a default value otherwise.
Examples
Basic usage:
>>>fromRight 1 (Right 3)3>>>fromRight 1 (Left "foo")1
Since: base-4.10.0.0
fromLeft :: a -> Either a b -> a #
Return the contents of a Left-value or a default value otherwise.
Examples
Basic usage:
>>>fromLeft 1 (Left 3)3>>>fromLeft 1 (Right "foo")1
Since: base-4.10.0.0
either :: (a -> c) -> (b -> c) -> Either a b -> c #
Case analysis for the Either type.
If the value is Left aa;
if it is Right bb.
Examples
We create two values of type Either String IntLeft constructor and another using the Right constructor. Then
we apply "either" the length function (if we have a String)
or the "times-two" function (if we have an Int):
>>>let s = Left "foo" :: Either String Int>>>let n = Right 3 :: Either String Int>>>either length (*2) s3>>>either length (*2) n6
Proxy is a type that holds no data, but has a phantom parameter of
arbitrary type (or even kind). Its use is to provide type information, even
though there is no value available of that type (or it may be too costly to
create one).
Historically, Proxy :: Proxy aundefined :: a
>>>Proxy :: Proxy (Void, Int -> Int)Proxy
Proxy can even hold types of higher kinds,
>>>Proxy :: Proxy EitherProxy
>>>Proxy :: Proxy FunctorProxy
>>>Proxy :: Proxy complicatedStructureProxy
Constructors
| Proxy |
Instances
| Generic1 (Proxy :: k -> Type) | |
| FoldableWithIndex Void (Proxy :: Type -> Type) | |
Defined in WithIndex | |
| FunctorWithIndex Void (Proxy :: Type -> Type) | |
| TraversableWithIndex Void (Proxy :: Type -> Type) | |
| RepeatWithIndex Void (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| SemialignWithIndex Void (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Void (Proxy :: Type -> Type) | |
| FromJSON1 (Proxy :: Type -> Type) | |
| ToJSON1 (Proxy :: TYPE LiftedRep -> Type) | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Proxy a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Proxy a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Proxy a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Proxy a] -> Encoding # | |
| Foldable (Proxy :: TYPE LiftedRep -> Type) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldMap' :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Eq1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| Ord1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Read1 (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
Defined in Data.Functor.Classes | |
| Show1 (Proxy :: TYPE LiftedRep -> Type) | Since: base-4.9.0.0 |
| Contravariant (Proxy :: Type -> Type) | |
| Traversable (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Alternative (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| Applicative (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Functor (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| Monad (Proxy :: Type -> Type) | Since: base-4.7.0.0 |
| MonadPlus (Proxy :: Type -> Type) | Since: base-4.9.0.0 |
| NFData1 (Proxy :: TYPE LiftedRep -> Type) | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| Hashable1 (Proxy :: Type -> Type) | |
Defined in Data.Hashable.Class | |
| Align (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| Repeat (Proxy :: Type -> Type) | |
Defined in Data.Semialign.Internal | |
| Semialign (Proxy :: Type -> Type) | |
| Unalign (Proxy :: Type -> Type) | |
| Unzip (Proxy :: Type -> Type) | |
| Zip (Proxy :: Type -> Type) | |
| FromJSON (Proxy a) | |
| ToJSON (Proxy a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data t => Data (Proxy t) | Since: base-4.7.0.0 |
Defined in Data.Data Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Proxy t -> c (Proxy t) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Proxy t) # toConstr :: Proxy t -> Constr # dataTypeOf :: Proxy t -> DataType # dataCast1 :: Typeable t0 => (forall d. Data d => c (t0 d)) -> Maybe (c (Proxy t)) # dataCast2 :: Typeable t0 => (forall d e. (Data d, Data e) => c (t0 d e)) -> Maybe (c (Proxy t)) # gmapT :: (forall b. Data b => b -> b) -> Proxy t -> Proxy t # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Proxy t -> r # gmapQ :: (forall d. Data d => d -> u) -> Proxy t -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Proxy t -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Proxy t -> m (Proxy t) # | |
| Monoid (Proxy s) | Since: base-4.7.0.0 |
| Semigroup (Proxy s) | Since: base-4.9.0.0 |
| Bounded (Proxy t) | Since: base-4.7.0.0 |
| Enum (Proxy s) | Since: base-4.7.0.0 |
| Generic (Proxy t) | |
| Ix (Proxy s) | Since: base-4.7.0.0 |
Defined in Data.Proxy | |
| Read (Proxy t) | Since: base-4.7.0.0 |
| Show (Proxy s) | Since: base-4.7.0.0 |
| NFData (Proxy a) | Since: deepseq-1.4.0.0 |
Defined in Control.DeepSeq | |
| Eq (Proxy s) | Since: base-4.7.0.0 |
| Ord (Proxy s) | Since: base-4.7.0.0 |
| Hashable (Proxy a) | |
Defined in Data.Hashable.Class | |
| Serialise (Proxy a) | Since: serialise-0.2.0.0 |
| type Rep1 (Proxy :: k -> Type) | Since: base-4.6.0.0 |
| type Rep (Proxy t) | Since: base-4.6.0.0 |
(>>>) :: forall {k} cat (a :: k) (b :: k) (c :: k). Category cat => cat a b -> cat b c -> cat a c infixr 1 #
Left-to-right composition
(<<<) :: forall {k} cat (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c infixr 1 #
Right-to-left composition
See openFile
Constructors
| ReadMode | |
| WriteMode | |
| AppendMode | |
| ReadWriteMode |
byteSwap64 :: Word64 -> Word64 #
Reverse order of bytes in Word64.
Since: base-4.7.0.0
byteSwap32 :: Word32 -> Word32 #
Reverse order of bytes in Word32.
Since: base-4.7.0.0
byteSwap16 :: Word16 -> Word16 #
Reverse order of bytes in Word16.
Since: base-4.7.0.0
toIntegralSized :: (Integral a, Integral b, Bits a, Bits b) => a -> Maybe b #
Attempt to convert an Integral type a to an Integral type b using
the size of the types as measured by Bits methods.
A simpler version of this function is:
toIntegral :: (Integral a, Integral b) => a -> Maybe b
toIntegral x
| toInteger x == y = Just (fromInteger y)
| otherwise = Nothing
where
y = toInteger xThis version requires going through Integer, which can be inefficient.
However, toIntegralSized is optimized to allow GHC to statically determine
the relative type sizes (as measured by bitSizeMaybe and isSigned) and
avoid going through Integer for many types. (The implementation uses
fromIntegral, which is itself optimized with rules for base types but may
go through Integer for some type pairs.)
Since: base-4.8.0.0
Extract the numerator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.
lcm :: Integral a => a -> a -> a #
lcm x yx and y divide.
gcd :: Integral a => a -> a -> a #
gcd x yx and y of which
every common factor of x and y is also a factor; for example
gcd 4 2 = 2gcd (-4) 6 = 2gcd 0 44. gcd 0 00.
(That is, the common divisor that is "greatest" in the divisibility
preordering.)
Note: Since for signed fixed-width integer types, abs minBound < 0minBound0 or minBound
denominator :: Ratio a -> a #
Extract the denominator of the ratio in reduced form: the numerator and denominator have no common factor and the denominator is positive.
(^^) :: (Fractional a, Integral b) => a -> b -> a infixr 8 #
raise a number to an integral power
boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a] #
boundedEnumFrom :: (Enum a, Bounded a) => a -> [a] #
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c] #
\(\mathcal{O}(\min(m,n))\). zipWith generalises zip by zipping with the
function given as the first argument, instead of a tupling function.
zipWith (,) xs ys == zip xs ys zipWith f [x1,x2,x3..] [y1,y2,y3..] == [f x1 y1, f x2 y2, f x3 y3..]
For example, zipWith (+)
>>>zipWith (+) [1, 2, 3] [4, 5, 6][5,7,9]
zipWith is right-lazy:
>>>let f = undefined>>>zipWith f [] undefined[]
zipWith is capable of list fusion, but it is restricted to its
first list argument and its resulting list.
unzip :: [(a, b)] -> ([a], [b]) #
unzip transforms a list of pairs into a list of first components
and a list of second components.
>>>unzip []([],[])>>>unzip [(1, 'a'), (2, 'b')]([1,2],"ab")
takeWhile :: (a -> Bool) -> [a] -> [a] #
takeWhile, applied to a predicate p and a list xs, returns the
longest prefix (possibly empty) of xs of elements that satisfy p.
>>>takeWhile (< 3) [1,2,3,4,1,2,3,4][1,2]>>>takeWhile (< 9) [1,2,3][1,2,3]>>>takeWhile (< 0) [1,2,3][]
take n, applied to a list xs, returns the prefix of xs
of length n, or xs itself if n >= .length xs
>>>take 5 "Hello World!""Hello">>>take 3 [1,2,3,4,5][1,2,3]>>>take 3 [1,2][1,2]>>>take 3 [][]>>>take (-1) [1,2][]>>>take 0 [1,2][]
It is an instance of the more general genericTake,
in which n may be of any integral type.
splitAt :: Int -> [a] -> ([a], [a]) #
splitAt n xs returns a tuple where first element is xs prefix of
length n and second element is the remainder of the list:
>>>splitAt 6 "Hello World!"("Hello ","World!")>>>splitAt 3 [1,2,3,4,5]([1,2,3],[4,5])>>>splitAt 1 [1,2,3]([1],[2,3])>>>splitAt 3 [1,2,3]([1,2,3],[])>>>splitAt 4 [1,2,3]([1,2,3],[])>>>splitAt 0 [1,2,3]([],[1,2,3])>>>splitAt (-1) [1,2,3]([],[1,2,3])
It is equivalent to ( when take n xs, drop n xs)n is not _|_
(splitAt _|_ xs = _|_).
splitAt is an instance of the more general genericSplitAt,
in which n may be of any integral type.
span :: (a -> Bool) -> [a] -> ([a], [a]) #
span, applied to a predicate p and a list xs, returns a tuple where
first element is longest prefix (possibly empty) of xs of elements that
satisfy p and second element is the remainder of the list:
>>>span (< 3) [1,2,3,4,1,2,3,4]([1,2],[3,4,1,2,3,4])>>>span (< 9) [1,2,3]([1,2,3],[])>>>span (< 0) [1,2,3]([],[1,2,3])
scanr1 :: (a -> a -> a) -> [a] -> [a] #
\(\mathcal{O}(n)\). scanr1 is a variant of scanr that has no starting
value argument.
>>>scanr1 (+) [1..4][10,9,7,4]>>>scanr1 (+) [][]>>>scanr1 (-) [1..4][-2,3,-1,4]>>>scanr1 (&&) [True, False, True, True][False,False,True,True]>>>scanr1 (||) [True, True, False, False][True,True,False,False]>>>force $ scanr1 (+) [1..]*** Exception: stack overflow
scanr :: (a -> b -> b) -> b -> [a] -> [b] #
\(\mathcal{O}(n)\). scanr is the right-to-left dual of scanl. Note that the order of parameters on the accumulating function are reversed compared to scanl.
Also note that
head (scanr f z xs) == foldr f z xs.
>>>scanr (+) 0 [1..4][10,9,7,4,0]>>>scanr (+) 42 [][42]>>>scanr (-) 100 [1..4][98,-97,99,-96,100]>>>scanr (\nextChar reversedString -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']["abcdfoo","bcdfoo","cdfoo","dfoo","foo"]>>>force $ scanr (+) 0 [1..]*** Exception: stack overflow
scanl1 :: (a -> a -> a) -> [a] -> [a] #
\(\mathcal{O}(n)\). scanl1 is a variant of scanl that has no starting
value argument:
scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
>>>scanl1 (+) [1..4][1,3,6,10]>>>scanl1 (+) [][]>>>scanl1 (-) [1..4][1,-1,-4,-8]>>>scanl1 (&&) [True, False, True, True][True,False,False,False]>>>scanl1 (||) [False, False, True, True][False,False,True,True]>>>scanl1 (+) [1..]* Hangs forever *
scanl :: (b -> a -> b) -> b -> [a] -> [b] #
\(\mathcal{O}(n)\). scanl is similar to foldl, but returns a list of
successive reduced values from the left:
scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
Note that
last (scanl f z xs) == foldl f z xs
>>>scanl (+) 0 [1..4][0,1,3,6,10]>>>scanl (+) 42 [][42]>>>scanl (-) 100 [1..4][100,99,97,94,90]>>>scanl (\reversedString nextChar -> nextChar : reversedString) "foo" ['a', 'b', 'c', 'd']["foo","afoo","bafoo","cbafoo","dcbafoo"]>>>scanl (+) 0 [1..]* Hangs forever *
replicate :: Int -> a -> [a] #
replicate n x is a list of length n with x the value of
every element.
It is an instance of the more general genericReplicate,
in which n may be of any integral type.
>>>replicate 0 True[]>>>replicate (-1) True[]>>>replicate 4 True[True,True,True,True]
repeat x is an infinite list, with x the value of every element.
>>>take 20 $ repeat 17[17,17,17,17,17,17,17,17,17...
iterate :: (a -> a) -> a -> [a] #
iterate f x returns an infinite list of repeated applications
of f to x:
iterate f x == [x, f x, f (f x), ...]
Note that iterate is lazy, potentially leading to thunk build-up if
the consumer doesn't force each iterate. See iterate' for a strict
variant of this function.
>>>take 10 $ iterate not True[True,False,True,False...>>>take 10 $ iterate (+3) 42[42,45,48,51,54,57,60,63...
drop n xs returns the suffix of xs
after the first n elements, or [] if n >= .length xs
>>>drop 6 "Hello World!""World!">>>drop 3 [1,2,3,4,5][4,5]>>>drop 3 [1,2][]>>>drop 3 [][]>>>drop (-1) [1,2][1,2]>>>drop 0 [1,2][1,2]
It is an instance of the more general genericDrop,
in which n may be of any integral type.
break :: (a -> Bool) -> [a] -> ([a], [a]) #
break, applied to a predicate p and a list xs, returns a tuple where
first element is longest prefix (possibly empty) of xs of elements that
do not satisfy p and second element is the remainder of the list:
>>>break (> 3) [1,2,3,4,1,2,3,4]([1,2,3],[4,1,2,3,4])>>>break (< 9) [1,2,3]([],[1,2,3])>>>break (> 9) [1,2,3]([1,2,3],[])
maybeToList :: Maybe a -> [a] #
The maybeToList function returns an empty list when given
Nothing or a singleton list when given Just.
Examples
Basic usage:
>>>maybeToList (Just 7)[7]
>>>maybeToList Nothing[]
One can use maybeToList to avoid pattern matching when combined
with a function that (safely) works on lists:
>>>import Text.Read ( readMaybe )>>>sum $ maybeToList (readMaybe "3")3>>>sum $ maybeToList (readMaybe "")0
maybe :: b -> (a -> b) -> Maybe a -> b #
The maybe function takes a default value, a function, and a Maybe
value. If the Maybe value is Nothing, the function returns the
default value. Otherwise, it applies the function to the value inside
the Just and returns the result.
Examples
Basic usage:
>>>maybe False odd (Just 3)True
>>>maybe False odd NothingFalse
Read an integer from a string using readMaybe. If we succeed,
return twice the integer; that is, apply (*2) to it. If instead
we fail to parse an integer, return 0 by default:
>>>import Text.Read ( readMaybe )>>>maybe 0 (*2) (readMaybe "5")10>>>maybe 0 (*2) (readMaybe "")0
Apply show to a Maybe Int. If we have Just n, we want to show
the underlying Int n. But if we have Nothing, we return the
empty string instead of (for example) "Nothing":
>>>maybe "" show (Just 5)"5">>>maybe "" show Nothing""
mapMaybe :: (a -> Maybe b) -> [a] -> [b] #
The mapMaybe function is a version of map which can throw
out elements. In particular, the functional argument returns
something of type Maybe bNothing, no element
is added on to the result list. If it is Just bb is
included in the result list.
Examples
Using mapMaybe f xcatMaybes $ map f x
>>>import Text.Read ( readMaybe )>>>let readMaybeInt = readMaybe :: String -> Maybe Int>>>mapMaybe readMaybeInt ["1", "Foo", "3"][1,3]>>>catMaybes $ map readMaybeInt ["1", "Foo", "3"][1,3]
If we map the Just constructor, the entire list should be returned:
>>>mapMaybe Just [1,2,3][1,2,3]
listToMaybe :: [a] -> Maybe a #
The listToMaybe function returns Nothing on an empty list
or Just aa is the first element of the list.
Examples
Basic usage:
>>>listToMaybe []Nothing
>>>listToMaybe [9]Just 9
>>>listToMaybe [1,2,3]Just 1
Composing maybeToList with listToMaybe should be the identity
on singleton/empty lists:
>>>maybeToList $ listToMaybe [5][5]>>>maybeToList $ listToMaybe [][]
But not on lists with more than one element:
>>>maybeToList $ listToMaybe [1,2,3][1]
fromMaybe :: a -> Maybe a -> a #
The fromMaybe function takes a default value and a Maybe
value. If the Maybe is Nothing, it returns the default value;
otherwise, it returns the value contained in the Maybe.
Examples
Basic usage:
>>>fromMaybe "" (Just "Hello, World!")"Hello, World!"
>>>fromMaybe "" Nothing""
Read an integer from a string using readMaybe. If we fail to
parse an integer, we want to return 0 by default:
>>>import Text.Read ( readMaybe )>>>fromMaybe 0 (readMaybe "5")5>>>fromMaybe 0 (readMaybe "")0
catMaybes :: [Maybe a] -> [a] #
The catMaybes function takes a list of Maybes and returns
a list of all the Just values.
Examples
Basic usage:
>>>catMaybes [Just 1, Nothing, Just 3][1,3]
When constructing a list of Maybe values, catMaybes can be used
to return all of the "success" results (if the list is the result
of a map, then mapMaybe would be more appropriate):
>>>import Text.Read ( readMaybe )>>>[readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ][Just 1,Nothing,Just 3]>>>catMaybes $ [readMaybe x :: Maybe Int | x <- ["1", "Foo", "3"] ][1,3]
Case analysis for the Bool type. bool x y px
when p is False, and evaluates to y when p is True.
This is equivalent to if p then y else x; that is, one can
think of it as an if-then-else construct with its arguments
reordered.
Examples
Basic usage:
>>>bool "foo" "bar" True"bar">>>bool "foo" "bar" False"foo"
Confirm that bool x y pif p then y else x are
equivalent:
>>>let p = True; x = "bar"; y = "foo">>>bool x y p == if p then y else xTrue>>>let p = False>>>bool x y p == if p then y else xTrue
Since: base-4.7.0.0
fix ff,
i.e. the least defined x such that f x = x.
For example, we can write the factorial function using direct recursion as
>>>let fac n = if n <= 1 then 1 else n * fac (n-1) in fac 5120
This uses the fact that Haskell’s let introduces recursive bindings. We can
rewrite this definition using fix,
>>>fix (\rec n -> if n <= 1 then 1 else n * rec (n-1)) 5120
Instead of making a recursive call, we introduce a dummy parameter rec;
when used within fix, this parameter then refers to fix’s argument, hence
the recursion is reintroduced.
void :: Functor f => f a -> f () #
void valueIO action.
Examples
Replace the contents of a Maybe Int
>>>void NothingNothing>>>void (Just 3)Just ()
Replace the contents of an Either Int IntEither Int ()
>>>void (Left 8675309)Left 8675309>>>void (Right 8675309)Right ()
Replace every element of a list with unit:
>>>void [1,2,3][(),(),()]
Replace the second element of a pair with unit:
>>>void (1,2)(1,())
Discard the result of an IO action:
>>>mapM print [1,2]1 2 [(),()]>>>void $ mapM print [1,2]1 2
($>) :: Functor f => f a -> b -> f b infixl 4 #
Flipped version of <$.
Examples
Replace the contents of a Maybe IntString:
>>>Nothing $> "foo"Nothing>>>Just 90210 $> "foo"Just "foo"
Replace the contents of an Either Int IntString, resulting in an Either
Int String
>>>Left 8675309 $> "foo"Left 8675309>>>Right 8675309 $> "foo"Right "foo"
Replace each element of a list with a constant String:
>>>[1,2,3] $> "foo"["foo","foo","foo"]
Replace the second element of a pair with a constant String:
>>>(1,2) $> "foo"(1,"foo")
Since: base-4.7.0.0
An MVar (pronounced "em-var") is a synchronising variable, used
for communication between concurrent threads. It can be thought of
as a box, which may be empty or full.
Instances
| NFData1 MVar | Since: deepseq-1.4.3.0 |
Defined in Control.DeepSeq | |
| NFData (MVar a) | NOTE: Only strict in the reference and not the referenced value. Since: deepseq-1.4.2.0 |
Defined in Control.DeepSeq | |
| Eq (MVar a) | Since: base-4.1.0.0 |
currentCallStack :: IO [String] #
Returns a [String] representing the current call stack. This
can be useful for debugging.
The implementation uses the call-stack simulation maintained by the
profiler, so it only works if the program was compiled with -prof
and contains suitable SCC annotations (e.g. by using -fprof-auto).
Otherwise, the list returned is likely to be empty or
uninformative.
Since: base-4.5.0.0
when :: Applicative f => Bool -> f () -> f () #
Conditional execution of Applicative expressions. For example,
when debug (putStrLn "Debugging")
will output the string Debugging if the Boolean value debug
is True, and otherwise do nothing.
liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d #
Lift a ternary function to actions.
(=<<) :: Monad m => (a -> m b) -> m a -> m b infixr 1 #
Same as >>=, but with the arguments interchanged.
($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b infixr 0 #
Strict (call-by-value) application operator. It takes a function and an argument, evaluates the argument to weak head normal form (WHNF), then calls the function with that value.
type HasCallStack = ?callStack :: CallStack #
Request a CallStack.
NOTE: The implicit parameter ?callStack :: CallStack is an
implementation detail and should not be considered part of the
CallStack API, we may decide to change the implementation in the
future.
Since: base-4.9.0.0
getCallStack :: CallStack -> [([Char], SrcLoc)] #
Extract a list of call-sites from the CallStack.
The list is ordered by most recent call.
Since: base-4.8.1.0
stimesIdempotentMonoid :: (Integral b, Monoid a) => b -> a -> a #
data SomeException #
The SomeException type is the root of the exception type hierarchy.
When an exception of type e is thrown, behind the scenes it is
encapsulated in a SomeException.
Constructors
| Exception e => SomeException e |
Instances
| Exception SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods toException :: SomeException -> SomeException # fromException :: SomeException -> Maybe SomeException # displayException :: SomeException -> String # | |
| Show SomeException | Since: base-3.0 |
Defined in GHC.Exception.Type Methods showsPrec :: Int -> SomeException -> ShowS # show :: SomeException -> String # showList :: [SomeException] -> ShowS # | |
fromShort :: ShortByteString -> ByteString #
O(n). Convert a ShortByteString into a ByteString.
data ShortByteString #
A compact representation of a Word8 vector.
It has a lower memory overhead than a ByteString and does not
contribute to heap fragmentation. It can be converted to or from a
ByteString (at the cost of copying the string data). It supports very few
other operations.
It is suitable for use as an internal representation for code that needs
to keep many short strings in memory, but it should not be used as an
interchange type. That is, it should not generally be used in public APIs.
The ByteString type is usually more suitable for use in interfaces; it is
more flexible and it supports a wide range of operations.
Instances
| Data ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ShortByteString -> c ShortByteString # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ShortByteString # toConstr :: ShortByteString -> Constr # dataTypeOf :: ShortByteString -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ShortByteString) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ShortByteString) # gmapT :: (forall b. Data b => b -> b) -> ShortByteString -> ShortByteString # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ShortByteString -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ShortByteString -> r # gmapQ :: (forall d. Data d => d -> u) -> ShortByteString -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> ShortByteString -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ShortByteString -> m ShortByteString # | |
| IsString ShortByteString | Beware: |
Defined in Data.ByteString.Short.Internal Methods fromString :: String -> ShortByteString # | |
| Monoid ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods mappend :: ShortByteString -> ShortByteString -> ShortByteString # mconcat :: [ShortByteString] -> ShortByteString # | |
| Semigroup ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (<>) :: ShortByteString -> ShortByteString -> ShortByteString # sconcat :: NonEmpty ShortByteString -> ShortByteString # stimes :: Integral b => b -> ShortByteString -> ShortByteString # | |
| IsList ShortByteString | Since: bytestring-0.10.12.0 |
Defined in Data.ByteString.Short.Internal Associated Types type Item ShortByteString # Methods fromList :: [Item ShortByteString] -> ShortByteString # fromListN :: Int -> [Item ShortByteString] -> ShortByteString # toList :: ShortByteString -> [Item ShortByteString] # | |
| Read ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods readsPrec :: Int -> ReadS ShortByteString # readList :: ReadS [ShortByteString] # | |
| Show ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods showsPrec :: Int -> ShortByteString -> ShowS # show :: ShortByteString -> String # showList :: [ShortByteString] -> ShowS # | |
| Binary ShortByteString | |
Defined in Data.Binary.Class Methods put :: ShortByteString -> Put # get :: Get ShortByteString # putList :: [ShortByteString] -> Put # | |
| NFData ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods rnf :: ShortByteString -> () # | |
| Eq ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods (==) :: ShortByteString -> ShortByteString -> Bool # (/=) :: ShortByteString -> ShortByteString -> Bool # | |
| Ord ShortByteString | |
Defined in Data.ByteString.Short.Internal Methods compare :: ShortByteString -> ShortByteString -> Ordering # (<) :: ShortByteString -> ShortByteString -> Bool # (<=) :: ShortByteString -> ShortByteString -> Bool # (>) :: ShortByteString -> ShortByteString -> Bool # (>=) :: ShortByteString -> ShortByteString -> Bool # max :: ShortByteString -> ShortByteString -> ShortByteString # min :: ShortByteString -> ShortByteString -> ShortByteString # | |
| Hashable ShortByteString | |
Defined in Data.Hashable.Class | |
| One ShortByteString | Create singleton
law> |
| EncodingError ToLText "ShortByteString" "LText" => ToLText ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toLText :: ShortByteString -> LText # | |
| EncodingError ToString "ShortByteString" "String" => ToString ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toString :: ShortByteString -> String # | |
| EncodingError ToText "ShortByteString" "Text" => ToText ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toText :: ShortByteString -> Text # | |
| Serialise ShortByteString | Since: serialise-0.2.0.0 |
Defined in Codec.Serialise.Class Methods encode :: ShortByteString -> Encoding # decode :: Decoder s ShortByteString # encodeList :: [ShortByteString] -> Encoding # decodeList :: Decoder s [ShortByteString] # | |
| ConvertUtf8 LText ShortByteString | Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods encodeUtf8 :: LText -> ShortByteString # decodeUtf8 :: ShortByteString -> LText # decodeUtf8Strict :: ShortByteString -> Either UnicodeException LText # | |
| ConvertUtf8 Text ShortByteString | Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods encodeUtf8 :: Text -> ShortByteString # decodeUtf8 :: ShortByteString -> Text # decodeUtf8Strict :: ShortByteString -> Either UnicodeException Text # | |
| ConvertUtf8 String ShortByteString | Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods encodeUtf8 :: String -> ShortByteString # decodeUtf8 :: ShortByteString -> String # decodeUtf8Strict :: ShortByteString -> Either UnicodeException String # | |
| Lift ShortByteString | Since: bytestring-0.11.2.0 |
Defined in Data.ByteString.Short.Internal Methods lift :: Quote m => ShortByteString -> m Exp # liftTyped :: forall (m :: Type -> Type). Quote m => ShortByteString -> Code m ShortByteString # | |
| type Item ShortByteString | |
Defined in Data.ByteString.Short.Internal | |
| type OneItem ShortByteString | |
Defined in Relude.Container.One | |
toShort :: ByteString -> ShortByteString #
O(n). Convert a ByteString into a ShortByteString.
This makes a copy, so does not retain the input string.
data IdentityT (f :: k -> Type) (a :: k) #
The trivial monad transformer, which maps a monad to an equivalent monad.
Instances
A map of integers to values a.
Instances
| FromJSON1 IntMap | |
| ToJSON1 IntMap | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> IntMap a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [IntMap a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> IntMap a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [IntMap a] -> Encoding # | |
| Foldable IntMap | Folds in order of increasing key. |
Defined in Data.IntMap.Internal Methods fold :: Monoid m => IntMap m -> m # foldMap :: Monoid m => (a -> m) -> IntMap a -> m # foldMap' :: Monoid m => (a -> m) -> IntMap a -> m # foldr :: (a -> b -> b) -> b -> IntMap a -> b # foldr' :: (a -> b -> b) -> b -> IntMap a -> b # foldl :: (b -> a -> b) -> b -> IntMap a -> b # foldl' :: (b -> a -> b) -> b -> IntMap a -> b # foldr1 :: (a -> a -> a) -> IntMap a -> a # foldl1 :: (a -> a -> a) -> IntMap a -> a # elem :: Eq a => a -> IntMap a -> Bool # maximum :: Ord a => IntMap a -> a # minimum :: Ord a => IntMap a -> a # | |
| Eq1 IntMap | Since: containers-0.5.9 |
| Ord1 IntMap | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal | |
| Read1 IntMap | Since: containers-0.5.9 |
Defined in Data.IntMap.Internal | |
| Show1 IntMap | Since: containers-0.5.9 |
| Traversable IntMap | Traverses in order of increasing key. |
| Functor IntMap | |
| Hashable1 IntMap | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Align IntMap | |
Defined in Data.Semialign.Internal | |
| Semialign IntMap | |
| Unalign IntMap | |
| Unzip IntMap | |
| Zip IntMap | |
| FoldableWithIndex Int IntMap | |
Defined in WithIndex | |
| FunctorWithIndex Int IntMap | |
| TraversableWithIndex Int IntMap | |
| SemialignWithIndex Int IntMap | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Int IntMap | |
| FromJSON a => FromJSON (IntMap a) | |
| ToJSON a => ToJSON (IntMap a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (IntMap a) | |
Defined in Data.IntMap.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> IntMap a -> c (IntMap a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (IntMap a) # toConstr :: IntMap a -> Constr # dataTypeOf :: IntMap a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (IntMap a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (IntMap a)) # gmapT :: (forall b. Data b => b -> b) -> IntMap a -> IntMap a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> IntMap a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> IntMap a -> r # gmapQ :: (forall d. Data d => d -> u) -> IntMap a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> IntMap a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> IntMap a -> m (IntMap a) # | |
| Monoid (IntMap a) | |
| Semigroup (IntMap a) | Since: containers-0.5.7 |
| IsList (IntMap a) | Since: containers-0.5.6.2 |
| Read e => Read (IntMap e) | |
| Show a => Show (IntMap a) | |
| Binary e => Binary (IntMap e) | |
| NFData a => NFData (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Eq a => Eq (IntMap a) | |
| Ord a => Ord (IntMap a) | |
Defined in Data.IntMap.Internal | |
| Hashable v => Hashable (IntMap v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| One (IntMap v) | Create singleton
law> |
| DynamicMap (IntMap v) | Since: relude-0.1.0 |
Defined in Relude.Extra.Map Methods insert :: Key (IntMap v) -> Val (IntMap v) -> IntMap v -> IntMap v # insertWith :: (Val (IntMap v) -> Val (IntMap v) -> Val (IntMap v)) -> Key (IntMap v) -> Val (IntMap v) -> IntMap v -> IntMap v # delete :: Key (IntMap v) -> IntMap v -> IntMap v # alter :: (Maybe (Val (IntMap v)) -> Maybe (Val (IntMap v))) -> Key (IntMap v) -> IntMap v -> IntMap v # | |
| StaticMap (IntMap v) | Since: relude-0.1.0 |
| Serialise a => Serialise (IntMap a) | Since: serialise-0.2.0.0 |
| type Item (IntMap a) | |
Defined in Data.IntMap.Internal | |
| type OneItem (IntMap v) | |
Defined in Relude.Container.One | |
| type Key (IntMap v) | |
Defined in Relude.Extra.Map | |
| type Val (IntMap v) | |
Defined in Relude.Extra.Map | |
A set of integers.
Instances
| FromJSON IntSet | |
| ToJSON IntSet | |
Defined in Data.Aeson.Types.ToJSON | |
| Data IntSet | |
Defined in Data.IntSet.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> IntSet -> c IntSet # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c IntSet # toConstr :: IntSet -> Constr # dataTypeOf :: IntSet -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c IntSet) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c IntSet) # gmapT :: (forall b. Data b => b -> b) -> IntSet -> IntSet # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> IntSet -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> IntSet -> r # gmapQ :: (forall d. Data d => d -> u) -> IntSet -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> IntSet -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> IntSet -> m IntSet # | |
| Monoid IntSet | |
| Semigroup IntSet | Since: containers-0.5.7 |
| IsList IntSet | Since: containers-0.5.6.2 |
| Read IntSet | |
| Show IntSet | |
| Binary IntSet | |
| NFData IntSet | |
Defined in Data.IntSet.Internal | |
| Eq IntSet | |
| Ord IntSet | |
| Hashable IntSet | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| One IntSet | Create singleton
law> |
| StaticMap IntSet | Since: relude-0.1.0 |
| Serialise IntSet | Since: serialise-0.2.0.0 |
| type Item IntSet | |
Defined in Data.IntSet.Internal | |
| type OneItem IntSet | |
Defined in Relude.Container.One | |
| type Key IntSet | |
Defined in Relude.Extra.Map | |
| type Val IntSet | |
Defined in Relude.Extra.Map | |
General-purpose finite sequences.
Instances
| FromJSON1 Seq | |
| ToJSON1 Seq | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Seq a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Seq a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Seq a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Seq a] -> Encoding # | |
| MonadFix Seq | Since: containers-0.5.11 |
Defined in Data.Sequence.Internal | |
| MonadZip Seq |
|
| Foldable Seq | |
Defined in Data.Sequence.Internal Methods fold :: Monoid m => Seq m -> m # foldMap :: Monoid m => (a -> m) -> Seq a -> m # foldMap' :: Monoid m => (a -> m) -> Seq a -> m # foldr :: (a -> b -> b) -> b -> Seq a -> b # foldr' :: (a -> b -> b) -> b -> Seq a -> b # foldl :: (b -> a -> b) -> b -> Seq a -> b # foldl' :: (b -> a -> b) -> b -> Seq a -> b # foldr1 :: (a -> a -> a) -> Seq a -> a # foldl1 :: (a -> a -> a) -> Seq a -> a # elem :: Eq a => a -> Seq a -> Bool # maximum :: Ord a => Seq a -> a # | |
| Eq1 Seq | Since: containers-0.5.9 |
| Ord1 Seq | Since: containers-0.5.9 |
Defined in Data.Sequence.Internal | |
| Read1 Seq | Since: containers-0.5.9 |
Defined in Data.Sequence.Internal | |
| Show1 Seq | Since: containers-0.5.9 |
| Traversable Seq | |
| Alternative Seq | Since: containers-0.5.4 |
| Applicative Seq | Since: containers-0.5.4 |
| Functor Seq | |
| Monad Seq | |
| MonadPlus Seq | |
| UnzipWith Seq | |
Defined in Data.Sequence.Internal Methods unzipWith' :: (x -> (a, b)) -> Seq x -> (Seq a, Seq b) | |
| Hashable1 Seq | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Align Seq | |
Defined in Data.Semialign.Internal | |
| Semialign Seq | |
| Unzip Seq | |
| Zip Seq | |
| FoldableWithIndex Int Seq | |
| FunctorWithIndex Int Seq | The position in the |
| TraversableWithIndex Int Seq | |
| SemialignWithIndex Int Seq | |
Defined in Data.Semialign.Internal | |
| ZipWithIndex Int Seq | |
| FromJSON a => FromJSON (Seq a) | |
| ToJSON a => ToJSON (Seq a) | |
Defined in Data.Aeson.Types.ToJSON | |
| Data a => Data (Seq a) | |
Defined in Data.Sequence.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Seq a -> c (Seq a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Seq a) # dataTypeOf :: Seq a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Seq a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Seq a)) # gmapT :: (forall b. Data b => b -> b) -> Seq a -> Seq a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Seq a -> r # gmapQ :: (forall d. Data d => d -> u) -> Seq a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Seq a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Seq a -> m (Seq a) # | |
| a ~ Char => IsString (Seq a) | Since: containers-0.5.7 |
Defined in Data.Sequence.Internal Methods fromString :: String -> Seq a # | |
| Monoid (Seq a) | |
| Semigroup (Seq a) | Since: containers-0.5.7 |
| IsList (Seq a) | |
| Read a => Read (Seq a) | |
| Show a => Show (Seq a) | |
| Binary e => Binary (Seq e) | |
| NFData a => NFData (Seq a) | |
Defined in Data.Sequence.Internal | |
| Eq a => Eq (Seq a) | |
| Ord a => Ord (Seq a) | |
| Hashable v => Hashable (Seq v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| Ord a => Stream (Seq a) | Since: megaparsec-9.0.0 |
Defined in Text.Megaparsec.Stream Methods tokenToChunk :: Proxy (Seq a) -> Token (Seq a) -> Tokens (Seq a) # tokensToChunk :: Proxy (Seq a) -> [Token (Seq a)] -> Tokens (Seq a) # chunkToTokens :: Proxy (Seq a) -> Tokens (Seq a) -> [Token (Seq a)] # chunkLength :: Proxy (Seq a) -> Tokens (Seq a) -> Int # chunkEmpty :: Proxy (Seq a) -> Tokens (Seq a) -> Bool # take1_ :: Seq a -> Maybe (Token (Seq a), Seq a) # takeN_ :: Int -> Seq a -> Maybe (Tokens (Seq a), Seq a) # takeWhile_ :: (Token (Seq a) -> Bool) -> Seq a -> (Tokens (Seq a), Seq a) # | |
| Extract (Seq a) | |
| One (Seq a) | Create singleton
law> |
| Serialise a => Serialise (Seq a) | Since: serialise-0.2.0.0 |
| type Item (Seq a) | |
Defined in Data.Sequence.Internal | |
| type Token (Seq a) | |
Defined in Text.Megaparsec.Stream | |
| type Tokens (Seq a) | |
Defined in Text.Megaparsec.Stream | |
| type OneItem (Seq a) | |
Defined in Relude.Container.One | |
A set of values a.
Instances
| ToJSON1 Set | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> Set a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [Set a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> Set a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [Set a] -> Encoding # | |
| Foldable Set | Folds in order of increasing key. |
Defined in Data.Set.Internal Methods fold :: Monoid m => Set m -> m # foldMap :: Monoid m => (a -> m) -> Set a -> m # foldMap' :: Monoid m => (a -> m) -> Set a -> m # foldr :: (a -> b -> b) -> b -> Set a -> b # foldr' :: (a -> b -> b) -> b -> Set a -> b # foldl :: (b -> a -> b) -> b -> Set a -> b # foldl' :: (b -> a -> b) -> b -> Set a -> b # foldr1 :: (a -> a -> a) -> Set a -> a # foldl1 :: (a -> a -> a) -> Set a -> a # elem :: Eq a => a -> Set a -> Bool # maximum :: Ord a => Set a -> a # | |
| Eq1 Set | Since: containers-0.5.9 |
| Ord1 Set | Since: containers-0.5.9 |
Defined in Data.Set.Internal | |
| Show1 Set | Since: containers-0.5.9 |
| Hashable1 Set | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| (Ord a, FromJSON a) => FromJSON (Set a) | |
| ToJSON a => ToJSON (Set a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Ord a) => Data (Set a) | |
Defined in Data.Set.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Set a -> c (Set a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Set a) # dataTypeOf :: Set a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Set a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Set a)) # gmapT :: (forall b. Data b => b -> b) -> Set a -> Set a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Set a -> r # gmapQ :: (forall d. Data d => d -> u) -> Set a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Set a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Set a -> m (Set a) # | |
| Ord a => Monoid (Set a) | |
| Ord a => Semigroup (Set a) | Since: containers-0.5.7 |
| Ord a => IsList (Set a) | Since: containers-0.5.6.2 |
| (Read a, Ord a) => Read (Set a) | |
| Show a => Show (Set a) | |
| Binary a => Binary (Set a) | |
| NFData a => NFData (Set a) | |
Defined in Data.Set.Internal | |
| Eq a => Eq (Set a) | |
| Ord a => Ord (Set a) | |
| Hashable v => Hashable (Set v) | Since: hashable-1.3.4.0 |
Defined in Data.Hashable.Class | |
| One (Set a) | Create singleton
law> |
| Ord a => StaticMap (Set a) | Since: relude-0.1.0 |
| (Ord a, Serialise a) => Serialise (Set a) | Since: serialise-0.2.0.0 |
| type Item (Set a) | |
Defined in Data.Set.Internal | |
| type OneItem (Set a) | |
Defined in Relude.Container.One | |
| type Key (Set a) | |
Defined in Relude.Extra.Map | |
| type Val (Set a) | |
Defined in Relude.Extra.Map | |
A class of types that can be fully evaluated.
Since: deepseq-1.1.0.0
Minimal complete definition
Nothing
Methods
rnf should reduce its argument to normal form (that is, fully
evaluate all sub-components), and then return ().
Generic NFData deriving
Starting with GHC 7.2, you can automatically derive instances
for types possessing a Generic instance.
Note: Generic1 can be auto-derived starting with GHC 7.4
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics (Generic, Generic1)
import Control.DeepSeq
data Foo a = Foo a String
deriving (Eq, Generic, Generic1)
instance NFData a => NFData (Foo a)
instance NFData1 Foo
data Colour = Red | Green | Blue
deriving Generic
instance NFData ColourStarting with GHC 7.10, the example above can be written more
concisely by enabling the new DeriveAnyClass extension:
{-# LANGUAGE DeriveGeneric, DeriveAnyClass #-}
import GHC.Generics (Generic)
import Control.DeepSeq
data Foo a = Foo a String
deriving (Eq, Generic, Generic1, NFData, NFData1)
data Colour = Red | Green | Blue
deriving (Generic, NFData)
Compatibility with previous deepseq versions
Prior to version 1.4.0.0, the default implementation of the rnf
method was defined as
rnfa =seqa ()
However, starting with deepseq-1.4.0.0, the default
implementation is based on DefaultSignatures allowing for
more accurate auto-derived NFData instances. If you need the
previously used exact default rnf method implementation
semantics, use
instance NFData Colour where rnf x = seq x ()
or alternatively
instance NFData Colour where rnf = rwhnf
or
{-# LANGUAGE BangPatterns #-}
instance NFData Colour where rnf !_ = ()Instances
deepseq :: NFData a => a -> b -> b #
deepseq: fully evaluates the first argument, before returning the
second.
The name deepseq is used to illustrate the relationship to seq:
where seq is shallow in the sense that it only evaluates the top
level of its argument, deepseq traverses the entire data structure
evaluating it completely.
deepseq can be useful for forcing pending exceptions,
eradicating space leaks, or forcing lazy I/O to happen. It is
also useful in conjunction with parallel Strategies (see the
parallel package).
There is no guarantee about the ordering of evaluation. The
implementation may evaluate the components of the structure in
any order or in parallel. To impose an actual order on
evaluation, use pseq from Control.Parallel in the
parallel package.
Since: deepseq-1.1.0.0
($!!) :: NFData a => (a -> b) -> a -> b infixr 0 #
the deep analogue of $!. In the expression f $!! x, x is
fully evaluated before the function f is applied to it.
Since: deepseq-1.2.0.0
newtype MaybeT (m :: Type -> Type) a #
The parameterizable maybe monad, obtained by composing an arbitrary
monad with the Maybe monad.
Computations are actions that may produce a value or exit.
The return function yields a computation that produces that
value, while >>= sequences two subcomputations, exiting if either
computation does.
Instances
newtype ExceptT e (m :: Type -> Type) a #
A monad transformer that adds exceptions to other monads.
ExceptT constructs a monad parameterized over two things:
- e - The exception type.
- m - The inner monad.
The return function yields a computation that produces the given
value, while >>= sequences two subcomputations, exiting on the
first exception.
Instances
class Monad m => MonadState s (m :: Type -> Type) | m -> s where #
Minimal definition is either both of get and put or just state
Methods
Return the state from the internals of the monad.
Replace the state inside the monad.
state :: (s -> (a, s)) -> m a #
Embed a simple state action into the monad.
Instances
newtype StateT s (m :: Type -> Type) a #
A state transformer monad parameterized by:
s- The state.m- The inner monad.
The return function leaves the state unchanged, while >>= uses
the final state of the first computation as the initial state of
the second.
Instances
class MonadTrans (t :: (Type -> Type) -> Type -> Type) where #
The class of monad transformers. Instances should satisfy the
following laws, which state that lift is a monad transformation:
Methods
lift :: Monad m => m a -> t m a #
Lift a computation from the argument monad to the constructed monad.
Instances
newtype ReaderT r (m :: Type -> Type) a #
The reader monad transformer, which adds a read-only environment to the given monad.
The return function ignores the environment, while >>= passes
the inherited environment to both subcomputations.
Constructors
| ReaderT | |
Fields
| |
Instances
modify' :: MonadState s m => (s -> s) -> m () #
A variant of modify in which the computation is strict in the
new state.
Since: mtl-2.2
modify :: MonadState s m => (s -> s) -> m () #
Monadic state transformer.
Maps an old state to a new state inside a state monad. The old state is thrown away.
Main> :t modify ((+1) :: Int -> Int)
modify (...) :: (MonadState Int a) => a ()This says that modify (+1) acts over any
Monad that is a member of the MonadState class,
with an Int state.
gets :: MonadState s m => (s -> a) -> m a #
Gets specific component of the state, using a projection function supplied.
class Monad m => MonadReader r (m :: Type -> Type) | m -> r where #
See examples in Control.Monad.Reader.
Note, the partially applied function type (->) r is a simple reader monad.
See the instance declaration below.
Methods
Retrieves the monad environment.
Arguments
| :: (r -> r) | The function to modify the environment. |
| -> m a |
|
| -> m a |
Executes a computation in a modified environment.
Arguments
| :: (r -> a) | The selector function to apply to the environment. |
| -> m a |
Retrieves a function of the current environment.
Instances
Arguments
| :: MonadReader r m | |
| => (r -> a) | The selector function to apply to the environment. |
| -> m a |
Retrieves a function of the current environment.
runExceptT :: ExceptT e m a -> m (Either e a) #
The inverse of ExceptT.
Arguments
| :: Reader r a | A |
| -> r | An initial environment. |
| -> a |
Runs a Reader and extracts the final value from it.
(The inverse of reader.)
Arguments
| :: (r' -> r) | The function to modify the environment. |
| -> Reader r a | Computation to run in the modified environment. |
| -> Reader r' a |
Execute a computation in a modified environment
(a specialization of withReaderT).
runReader(withReaderf m) =runReaderm . f
Arguments
| :: forall r' r (m :: Type -> Type) a. (r' -> r) | The function to modify the environment. |
| -> ReaderT r m a | Computation to run in the modified environment. |
| -> ReaderT r' m a |
Execute a computation in a modified environment
(a more general version of local).
runReaderT(withReaderTf m) =runReaderTm . f
type Reader r = ReaderT r Identity #
The parameterizable reader monad.
Computations are functions of a shared environment.
The return function ignores the environment, while >>= passes
the inherited environment to both subcomputations.
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial value |
| -> a | return value of the state computation |
evalStateT :: Monad m => StateT s m a -> s -> m a #
Evaluate a state computation with the given initial state and return the final value, discarding the final state.
evalStateTm s =liftMfst(runStateTm s)
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial value |
| -> s | final state |
execStateT :: Monad m => StateT s m a -> s -> m s #
Evaluate a state computation with the given initial state and return the final state, discarding the final value.
execStateTm s =liftMsnd(runStateTm s)
Arguments
| :: State s a | state-passing computation to execute |
| -> s | initial state |
| -> (a, s) | return value and final state |
Unwrap a state monad computation as a function.
(The inverse of state.)
type State s = StateT s Identity #
A state monad parameterized by the type s of the state to carry.
The return function leaves the state unchanged, while >>= uses
the final state of the first computation as the initial state of
the second.
lookupEnv :: MonadIO m => String -> m (Maybe String) #
Lifted version of lookupEnv.
Since: relude-1.0.0.0
anyM :: (Foldable f, Monad m) => (a -> m Bool) -> f a -> m Bool #
Monadic version of any.
>>>anyM (readMaybe >=> pure . even) ["5", "10"]Just True>>>anyM (readMaybe >=> pure . even) ["10", "aba"]Just True>>>anyM (readMaybe >=> pure . even) ["aba", "10"]Nothing
allM :: (Foldable f, Monad m) => (a -> m Bool) -> f a -> m Bool #
Monadic version of all.
>>>allM (readMaybe >=> pure . even) ["6", "10"]Just True>>>allM (readMaybe >=> pure . even) ["5", "aba"]Just False>>>allM (readMaybe >=> pure . even) ["aba", "10"]Nothing
orM :: (Foldable f, Monad m) => f (m Bool) -> m Bool #
Monadic version of or.
>>>orM [Just True, Just False]Just True>>>orM [Just True, Nothing]Just True>>>orM [Nothing, Just True]Nothing
andM :: (Foldable f, Monad m) => f (m Bool) -> m Bool #
Monadic version of and.
>>>andM [Just True, Just False]Just False>>>andM [Just True]Just True>>>andM [Just True, Just False, Nothing]Just False>>>andM [Just True, Nothing]Nothing>>>andM [putTextLn "1" >> pure True, putTextLn "2" >> pure False, putTextLn "3" >> pure True]1 2 False
notElem :: (Foldable f, DisallowElem f, Eq a) => a -> f a -> Bool #
Like notElem but doesn't work on Set and HashSet for performance reasons.
>>>notElem 'x' ("abc" :: String)True>>>notElem False (one True :: Set Bool)... ... Do not use 'elem' and 'notElem' methods from 'Foldable' on Set Suggestions: Instead of elem :: (Foldable t, Eq a) => a -> t a -> Bool use member :: Ord a => a -> Set a -> Bool ... Instead of notElem :: (Foldable t, Eq a) => a -> t a -> Bool use not . member ...
elem :: (Foldable f, DisallowElem f, Eq a) => a -> f a -> Bool #
Like elem but doesn't work on Set and HashSet for performance reasons.
>>>elem 'x' ("abc" :: String)False>>>elem False (one True :: Set Bool)... ... Do not use 'elem' and 'notElem' methods from 'Foldable' on Set Suggestions: Instead of elem :: (Foldable t, Eq a) => a -> t a -> Bool use member :: Ord a => a -> Set a -> Bool ... Instead of notElem :: (Foldable t, Eq a) => a -> t a -> Bool use not . member ...
product :: forall a f. (Foldable f, Num a) => f a -> a #
Stricter version of product.
>>>product [1..10]3628800
foldMapM :: (Monoid b, Monad m, Foldable f) => (a -> m b) -> f a -> m b #
Polymorphic version of the concatMapM function.
>>>foldMapM @[Int] (Just . replicate 3) [1..3]Just [1,1,1,2,2,2,3,3,3]
Since: relude-0.1.0
foldMapA :: (Semigroup b, Monoid b, Applicative m, Foldable f) => (a -> m b) -> f a -> m b #
Polymorphic version of the concatMapA function.
>>>foldMapA @[Int] (Just . replicate 3) [1..3]Just [1,1,1,2,2,2,3,3,3]
Since: relude-0.1.0
asumMap :: forall b m f a. (Foldable f, Alternative m) => (a -> m b) -> f a -> m b #
Alternative version of asum that takes a function to map over.
>>>asumMap (\x -> if x > 2 then Just x else Nothing) [1..4]Just 3
Since: relude-0.4.0
flipfoldl' :: Foldable f => (a -> b -> b) -> b -> f a -> b #
Similar to foldl' but takes a function with its arguments flipped.
>>>flipfoldl' (/) 5 [2,3] :: Rational15 % 2
This function can be useful for constructing containers from lists.
newEmptyTMVarIO :: MonadIO m => m (TMVar a) #
Lifted to MonadIO version of newEmptyTMVarIO.
newTMVarIO :: MonadIO m => a -> m (TMVar a) #
Lifted to MonadIO version of newTMVarIO.
readTVarIO :: MonadIO m => TVar a -> m a #
Lifted to MonadIO version of readTVarIO.
atomically :: MonadIO m => STM a -> m a #
Lifted to MonadIO version of atomically.
tryTakeMVar :: MonadIO m => MVar a -> m (Maybe a) #
Lifted to MonadIO version of tryTakeMVar.
tryReadMVar :: MonadIO m => MVar a -> m (Maybe a) #
Lifted to MonadIO version of tryReadMVar.
tryPutMVar :: MonadIO m => MVar a -> a -> m Bool #
Lifted to MonadIO version of tryPutMVar.
newEmptyMVar :: MonadIO m => m (MVar a) #
Lifted to MonadIO version of newEmptyMVar.
hGetBuffering :: MonadIO m => Handle -> m BufferMode #
Lifted version of hGetBuffering.
Since: relude-1.0.0.0
hSetBuffering :: MonadIO m => Handle -> BufferMode -> m () #
Lifted version of hSetBuffering.
Since: relude-1.0.0.0
partitionWith :: (a -> Either b c) -> [a] -> ([b], [c]) #
Partitions a list based on the result of function which produces an Either value. List of all elements producing Left are extracted, in order, to the first element of the output tuple. Similarly, a list of all elements producing Right are extracted to the second element of output.
>>>:{divideEvenOrShow :: Int -> Either Int String divideEvenOrShow n | even n = Left $ n `div` 2 | otherwise = Right $ "Odd: " <> show n :}
>>>partitionWith divideEvenOrShow [1 .. 6]([1,2,3],["Odd: 1","Odd: 3","Odd: 5"])
Since: relude-1.0.0.0
maybeAt :: Int -> [a] -> Maybe a #
!!? with its arguments flipped.
Get element from list using index value starting from `0`.
>>>maybeAt 0 []Nothing
>>>maybeAt 3 ["a", "b", "c"]Nothing
>>>maybeAt (-1) [1, 2, 3]Nothing
>>>maybeAt 2 ["a", "b", "c"]Just "c"
Since: relude-1.0.0.0
(!!?) :: [a] -> Int -> Maybe a infix 9 #
Safer version of !!, returns a Maybe.
Get element from list using index value starting from `0`.
>>>[] !!? 0Nothing
>>>["a", "b", "c"] !!? 3Nothing
>>>[1, 2, 3] !!? (-1)Nothing
>>>["a", "b", "c"] !!? 2Just "c"
Since: relude-0.6.0.0
Type of a single element of the structure.
Instances
| type OneItem ByteString | |
Defined in Relude.Container.One | |
| type OneItem ByteString | |
Defined in Relude.Container.One | |
| type OneItem ShortByteString | |
Defined in Relude.Container.One | |
| type OneItem IntSet | |
Defined in Relude.Container.One | |
| type OneItem Assumption Source # | |
Defined in Nix.Type.Assumption | |
| type OneItem Env Source # | |
Defined in Nix.Type.Env | |
| type OneItem Text | |
Defined in Relude.Container.One | |
| type OneItem Text | |
Defined in Relude.Container.One | |
| type OneItem (IntMap v) | |
Defined in Relude.Container.One | |
| type OneItem (Seq a) | |
Defined in Relude.Container.One | |
| type OneItem (Set a) | |
Defined in Relude.Container.One | |
| type OneItem (Scope a) Source # | |
| type OneItem (HashSet a) | |
Defined in Relude.Container.One | |
| type OneItem (NonEmpty a) | |
Defined in Relude.Container.One | |
| type OneItem [a] | |
Defined in Relude.Container.One type OneItem [a] = a | |
| type OneItem (Map k v) | |
Defined in Relude.Container.One | |
| type OneItem (HashMap k v) | |
Defined in Relude.Container.One | |
Typeclass for data types that can be created from one element. E.g. lists, non-empty containers, maps.
>>>one True :: [Bool][True]>>>one 'a' :: Text"a">>>one (3, "hello") :: HashMap Int StringfromList [(3,"hello")]
Laws:
single-size:∀ x . size (one x) ≡ 1
(where size is a specific function for each container that returns the size of
this container)
Instances
| One ByteString | Create singleton strict
law> |
Defined in Relude.Container.One Associated Types type OneItem ByteString # Methods one :: OneItem ByteString -> ByteString # | |
| One ByteString | Create singleton lazy
law> |
Defined in Relude.Container.One Associated Types type OneItem ByteString # Methods one :: OneItem ByteString -> ByteString # | |
| One ShortByteString | Create singleton
law> |
| One IntSet | Create singleton
law> |
| One Assumption Source # | |
Defined in Nix.Type.Assumption Associated Types type OneItem Assumption # Methods one :: OneItem Assumption -> Assumption # | |
| One Env Source # | |
| One Text | Create singleton strict
law> |
| One Text | Create singleton lazy
law> |
| One (IntMap v) | Create singleton
law> |
| One (Seq a) | Create singleton
law> |
| One (Set a) | Create singleton
law> |
| One (Scope a) Source # | |
| Hashable a => One (HashSet a) | Create singleton
law> |
| One (NonEmpty a) | Allows to create singleton
law> |
| One [a] | Allows to create a singleton list. You might prefer function with name
law> |
| One (Map k v) | Create singleton
law> |
| Hashable k => One (HashMap k v) | Create singleton
law> |
integerToNatural :: Integer -> Maybe Natural #
Transforms an integer number to a natural.
Only non-negative integers are considered natural, everything else will return Nothing.
>>>integerToNatural (-1)Nothing
>>>integerToNatural 0Just 0
>>>integerToNatural 10Just 10
Since: relude-0.5.0
integerToBounded :: (Integral a, Bounded a) => Integer -> Maybe a #
Transforms an integer number to a bounded integral.
It returns Nothing for integers outside the bound of the return type.
>>>integerToBounded @Int 42Just 42
>>>integerToBounded @Int8 1024Nothing
>>>integerToBounded @Int (toInteger (minBound :: Int))Just (-9223372036854775808)>>>integerToBounded @Int $ (toInteger (minBound :: Int)) - 1Nothing
>>>integerToBounded @Int (toInteger (maxBound :: Int))Just 9223372036854775807>>>integerToBounded @Int $ (toInteger (maxBound :: Int)) + 1Nothing
If you want to convert Int or Word to a bounded type, take a look at
toIntegralSized function instead.
Since: relude-0.5.0
(||^) :: Monad m => m Bool -> m Bool -> m Bool #
Monadic version of (||) operator.
It is lazy by the second argument (similar to (||)), meaning that if
the first argument is True, the function will return True without evaluating
the second argument.
>>>Just False ||^ Just TrueJust True>>>Just False ||^ Just FalseJust False>>>Just False ||^ NothingNothing>>>Just True ||^ NothingJust True>>>Just True ||^ error "Shouldn't be evaluated"Just True
Since: relude-0.4.0
(&&^) :: Monad m => m Bool -> m Bool -> m Bool #
Monadic version of (&&) operator.
It is lazy by the second argument (similar to (||)), meaning that if
the first argument is False, the function will return False without evaluating
the second argument.
>>>Just False &&^ Just TrueJust False>>>Just True &&^ Just TrueJust True>>>Just True &&^ NothingNothing>>>Just False &&^ NothingJust False>>>Just False &&^ error "Shouldn't be evaluated"Just False
Since: relude-0.4.0
guarded :: Alternative f => (a -> Bool) -> a -> f a #
Either lifts a value into an alternative context or gives a
minimal value depending on a predicate. Works with Alternatives.
>>>guarded even 3 :: [Int][]>>>guarded even 2 :: [Int][2]>>>guarded (const True) "hello" :: Maybe StringJust "hello">>>guarded (const False) "world" :: Maybe StringNothing
You can use this function to implement smart constructors simpler:
newtype HttpHost = HttpHost
{ unHttpHost :: Text
}
mkHttpHost :: Text -> Maybe HttpHost
mkHttpHost host = HttpHost <$> guarded (not . Text.null) host
Since: relude-0.6.0.0
guardM :: MonadPlus m => m Bool -> m () #
Monadic version of guard that help to check that a condition (Bool)
holds inside. Works with Monads that are also Alternative.
>>>guardM (Just True)Just ()>>>guardM (Just False)Nothing>>>guardM NothingNothing
Here some complex but real-life example:
findSomePath :: IO (Maybe FilePath)
somePath :: MaybeT IO FilePath
somePath = do
path <- MaybeT findSomePath
guardM $ liftIO $ doesDirectoryExist path
return path
ifM :: Monad m => m Bool -> m a -> m a -> m a #
Monadic version of if-then-else.
>>>ifM (pure True) (putTextLn "True text") (putTextLn "False text")True text>>>ifM (pure False) (putTextLn "True text") (putTextLn "False text")False text
whenM :: Monad m => m Bool -> m () -> m () #
Monadic version of when.
Conditionally executes the provided action.
>>>whenM (pure False) $ putTextLn "No text :(">>>whenM (pure True) $ putTextLn "Yes text :)"Yes text :)>>>whenM (Just True) (pure ())Just ()>>>whenM (Just False) (pure ())Just ()>>>whenM Nothing (pure ())Nothing
evaluateNF_ :: (NFData a, MonadIO m) => a -> m () #
Alias for evaluateWHNF . rnf. Similar to evaluateNF
but discards the resulting value.
>>>let list = [1..5] :: [Int]>>>:sprint listlist = _>>>evaluateNF_ list>>>:sprint listlist = [1,2,3,4,5]
evaluateNF :: (NFData a, MonadIO m) => a -> m a #
Alias for evaluateWHNF . force with a clearer name.
>>>let list = [1..5] :: [Int]>>>:sprint listlist = _>>>() <$ evaluateNF list>>>:sprint listlist = [1,2,3,4,5]
evaluateWHNF_ :: MonadIO m => a -> m () #
Like evaluateWHNF but discards value.
>>>let list = [1..5] :: [Int]>>>:sprint listlist = _>>>evaluateWHNF_ list>>>:sprint listlist = 1 : _
evaluateWHNF :: MonadIO m => a -> m a #
Lifted alias for evaluate with a clearer name.
>>>let list = [1..5] :: [Int]>>>:sprint listlist = _>>>() <$ evaluateWHNF list>>>:sprint listlist = 1 : _
bug :: (HasCallStack, Exception e) => e -> a #
Generate a pure value which, when forced, will synchronously
throw the exception wrapped into Bug data type.
pattern Exc :: Exception e => e -> SomeException #
Pattern synonym to easy pattern matching on exceptions. So instead of writing something like this:
isNonCriticalExc :: SomeException -> Bool
isNonCriticalExc e
| Just (_ :: NodeAttackedError) <- fromException e = True
| Just DialogUnexpected{} <- fromException e = True
| otherwise = False
you can use Exc pattern synonym:
isNonCriticalExc :: SomeException -> Bool
isNonCriticalExc = case
Exc (_ :: NodeAttackedError) -> True -- matching all exceptions of type NodeAttackedError
Exc DialogUnexpected{} -> True
_ -> False
This pattern is bidirectional. You can use Exc e instead of toException e.
Type that represents exceptions used in cases when a particular codepath is not meant to be ever executed, but happens to be executed anyway.
Constructors
| Bug SomeException CallStack |
Instances
| Exception Bug | |
Defined in Relude.Exception Methods toException :: Bug -> SomeException # fromException :: SomeException -> Maybe Bug # displayException :: Bug -> String # | |
| Show Bug | |
tail :: IsNonEmpty f a [a] "tail" => f a -> [a] #
O(1). Return all the elements of a NonEmpty list after the head
element.
Actual type of this function is the following:
tail :: NonEmpty a -> [a]
but it was given a more complex type to provide friendlier compile time errors.
>>>tail ('a' :| "bcde")"bcde">>>tail [0..5 :: Int]... ... 'tail' works with 'NonEmpty', not ordinary lists. Possible fix: Replace: [Int] With: NonEmpty Int ... However, you can use 'tail' with the ordinary lists. Apply 'viaNonEmpty' function from relude: viaNonEmpty tail (yourList) Note, that this will return 'Maybe [Int]' therefore it is a safe function unlike 'tail' from the standard Prelude ...>>>tail (Just 'a')... ... 'tail' works with 'NonEmpty Char' lists But given: Maybe Char ...
last :: IsNonEmpty f a a "last" => f a -> a #
O(n). Extracts the last element of a NonEmpty list.
Actual type of this function is the following:
last :: NonEmpty a -> a
but it was given a more complex type to provide friendlier compile time errors.
>>>last ('a' :| "bcde")'e'>>>last [0..5 :: Int]... ... 'last' works with 'NonEmpty', not ordinary lists. Possible fix: Replace: [Int] With: NonEmpty Int ... However, you can use 'last' with the ordinary lists. Apply 'viaNonEmpty' function from relude: viaNonEmpty last (yourList) Note, that this will return 'Maybe Int' therefore it is a safe function unlike 'last' from the standard Prelude ...>>>last (Just 'a')... ... 'last' works with 'NonEmpty Char' lists But given: Maybe Char ...
init :: IsNonEmpty f a [a] "init" => f a -> [a] #
O(n). Return all the elements of a NonEmpty list except the last one
element.
Actual type of this function is the following:
init :: NonEmpty a -> [a]
but it was given a more complex type to provide friendlier compile time errors.
>>>init ('a' :| "bcde")"abcd">>>init [0..5 :: Int]... ... 'init' works with 'NonEmpty', not ordinary lists. Possible fix: Replace: [Int] With: NonEmpty Int ... However, you can use 'init' with the ordinary lists. Apply 'viaNonEmpty' function from relude: viaNonEmpty init (yourList) Note, that this will return 'Maybe [Int]' therefore it is a safe function unlike 'init' from the standard Prelude ...>>>init (Just 'a')... ... 'init' works with 'NonEmpty Char' lists But given: Maybe Char ...
head :: IsNonEmpty f a a "head" => f a -> a #
O(1). Extracts the first element of a NonEmpty list.
Actual type of this function is the following:
head :: NonEmpty a -> a
but it was given a more complex type to provide friendlier compile time errors.
>>>head ('a' :| "bcde")'a'>>>head [0..5 :: Int]... ... 'head' works with 'NonEmpty', not ordinary lists. Possible fix: Replace: [Int] With: NonEmpty Int ... However, you can use 'head' with the ordinary lists. Apply 'viaNonEmpty' function from relude: viaNonEmpty head (yourList) Note, that this will return 'Maybe Int' therefore it is a safe function unlike 'head' from the standard Prelude ...>>>head (Just 'a')... ... 'head' works with 'NonEmpty Char' lists But given: Maybe Char ...
whenNotNullM :: Monad m => m [a] -> (NonEmpty a -> m ()) -> m () #
Monadic version of whenNotNull.
whenNotNull :: Applicative f => [a] -> (NonEmpty a -> f ()) -> f () #
Performs given action over NonEmpty list if given list is non empty.
>>>whenNotNull [] $ \(b :| _) -> print (not b)>>>whenNotNull [False,True] $ \(b :| _) -> print (not b)True
viaNonEmpty :: (NonEmpty a -> b) -> [a] -> Maybe b #
For safe work with lists using functions for NonEmpty.
>>>viaNonEmpty head [1]Just 1>>>viaNonEmpty head []Nothing
Since: relude-0.1.0
infinitely :: Applicative f => f a -> f Void #
Repeat a monadic action indefinitely.
This is a more type safe version of forever, which has a convenient
but unsafe type.
Consider the following two examples. In the getIntForever functions, it
falsely expects Int as the result of the forever function. But it would need
to wait *forever* to get that, and this mistake won't be caught by the type
system and compiler:
getIntForever :: IO Int
getIntForever = do
i <- forever $ do ...
pure i
In contrast, using infinitely instead of forever in foo is a type error.
Since: relude-1.0.0.0
chainedTo :: Monad m => (a -> m b) -> m a -> m b #
For chaining monadic operations in forward applications using (&)
Named version of =<<.
>>>Just [ 1 :: Int ] & chainedTo (viaNonEmpty head)Just 1>>>Nothing & chainedTo (viaNonEmpty head)Nothing
Since: relude-0.5.0
whenRightM_ :: Monad m => m (Either l r) -> (r -> m ()) -> m () #
Monadic version of whenRight_.
>>>whenRightM_ (pure $ Left "foo") print>>>whenRightM_ (pure $ Right 42) print42
whenRightM :: Monad m => a -> m (Either l r) -> (r -> m a) -> m a #
Monadic version of whenRight.
>>>whenRightM "bar" (pure $ Left "foo") (\a -> "success!" <$ print a)"bar"
>>>whenRightM "bar" (pure $ Right 42) (\a -> "success!" <$ print a)42 "success!"
whenRight_ :: Applicative f => Either l r -> (r -> f ()) -> f () #
whenRight :: Applicative f => a -> Either l r -> (r -> f a) -> f a #
whenLeftM_ :: Monad m => m (Either l r) -> (l -> m ()) -> m () #
Monadic version of whenLeft_.
>>>whenLeftM_ (pure $ Right 42) putTextLn>>>whenLeftM_ (pure $ Left "foo") putTextLnfoo
whenLeftM :: Monad m => a -> m (Either l r) -> (l -> m a) -> m a #
Monadic version of whenLeft.
>>>whenLeftM "bar" (pure $ Left 42) (\a -> "success!" <$ print a)42 "success!"
>>>whenLeftM "bar" (pure $ Right 42) (\a -> "success!" <$ print a)"bar"
whenLeft_ :: Applicative f => Either l r -> (l -> f ()) -> f () #
whenLeft :: Applicative f => a -> Either l r -> (l -> f a) -> f a #
maybeToLeft :: r -> Maybe l -> Either l r #
maybeToRight :: l -> Maybe r -> Either l r #
rightToMaybe :: Either l r -> Maybe r #
leftToMaybe :: Either l r -> Maybe l #
undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a #
undefined that leaves warning in code on every usage.
error :: forall (r :: RuntimeRep) (a :: TYPE r) t. (HasCallStack, IsText t) => t -> a #
Throw pure errors. Use this function only to when you are sure that this
branch of code execution is not possible. DO NOT USE error as a normal
error handling mechanism.
>>>error "oops"*** Exception: oops CallStack (from HasCallStack): error, called at src/Relude/Debug.hs:296:11 in ... ...
⚠️CAUTION⚠️ Unlike Prelude version, error takes Text as an
argument. In case it used by mistake, the user will see the following:
>>>error ("oops" :: String)... ... 'error' expects 'Text' but was given 'String'. Possible fixes: * Make sure OverloadedStrings extension is enabled * Use 'error (toText msg)' instead of 'error msg' ...>>>error False... ... 'error' works with 'Text' But given: Bool ...
Similar to traceShowId but specialised for String.
>>>traceId "hello""hello hello"
traceShowM :: (Show a, Applicative f) => a -> f () #
traceShowWith :: Show b => (a -> b) -> a -> a #
Similar traceShowId, but uses a provided function to convert the
argument to a value with the Show constraint.
>>>traceShowWith fst (1, "ABC")1 (1,"ABC")
In other words, traceShowId ≡ traceShowWith id
This function is useful for debugging values that do not have Show
instance:
>>>fst $ traceShowWith fst (1, id)1 1
- If you don't need such flexibility, use simpler
trace,traceShowortraceShowId
Since: relude-1.0.0.0
traceShowId :: Show a => a -> a #
Similar to traceShow but prints the given value itself instead
of a separate value.
>>>traceShowId (1+2+3, "hello" ++ "world")(6,"helloworld") (6,"helloworld")
- If you to specify a different value to print, use
traceortraceShow - If you want to have more control over printing, use
traceShowWith
traceShow :: Show a => a -> b -> b #
Similar to trace but prints a given value with the Show
instance instead of a String.
>>>increment l = map (+1) l>>>increment [2, 3, 4][3,4,5]
>>>increment l = traceShow l (map (+1) l)>>>increment [2, 3, 4][2,3,4] [3,4,5]
- If you want to print a specific
Stringinstead, usetrace - If you want to print and return the same value, use
traceShowId - If you want to specify a custom printing function, use
traceShowWith
Similar to undefined but data type.
Constructors
| Undefined |
Instances
| Data Undefined | |
Defined in Relude.Debug Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Undefined -> c Undefined # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Undefined # toConstr :: Undefined -> Constr # dataTypeOf :: Undefined -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Undefined) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Undefined) # gmapT :: (forall b. Data b => b -> b) -> Undefined -> Undefined # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Undefined -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Undefined -> r # gmapQ :: (forall d. Data d => d -> u) -> Undefined -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Undefined -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Undefined -> m Undefined # | |
| Bounded Undefined | |
| Enum Undefined | |
Defined in Relude.Debug Methods succ :: Undefined -> Undefined # pred :: Undefined -> Undefined # fromEnum :: Undefined -> Int # enumFrom :: Undefined -> [Undefined] # enumFromThen :: Undefined -> Undefined -> [Undefined] # enumFromTo :: Undefined -> Undefined -> [Undefined] # enumFromThenTo :: Undefined -> Undefined -> Undefined -> [Undefined] # | |
| Generic Undefined | |
| Read Undefined | |
| Show Undefined | |
| Eq Undefined | |
| Ord Undefined | |
| type Rep Undefined | |
appendFileLBS :: MonadIO m => FilePath -> LByteString -> m () #
Lifted version of appendFile.
Since: relude-0.3.0
writeFileLBS :: MonadIO m => FilePath -> LByteString -> m () #
Lifted version of writeFile.
Since: relude-0.3.0
readFileLBS :: MonadIO m => FilePath -> m LByteString #
Lifted version of readFile.
Since: relude-0.3.0
appendFileBS :: MonadIO m => FilePath -> ByteString -> m () #
Lifted version of appendFile.
Since: relude-0.3.0
writeFileBS :: MonadIO m => FilePath -> ByteString -> m () #
Lifted version of writeFile.
Since: relude-0.3.0
readFileBS :: MonadIO m => FilePath -> m ByteString #
Lifted version of readFile.
Since: relude-0.3.0
appendFileLText :: MonadIO m => FilePath -> LText -> m () #
Lifted version of appendFile.
Since: relude-0.3.0
writeFileLText :: MonadIO m => FilePath -> LText -> m () #
Lifted version of writeFile.
Since: relude-0.3.0
appendFileText :: MonadIO m => FilePath -> Text -> m () #
Lifted version of appendFile.
Since: relude-0.3.0
writeFileText :: MonadIO m => FilePath -> Text -> m () #
Lifted version of writeFile.
Since: relude-0.3.0
appendFile :: MonadIO m => FilePath -> String -> m () #
Lifted version of appendFile.
putLBSLn :: MonadIO m => LByteString -> m () #
Lifted version of putStrLn.
>>>putLBSLn ("Hello, world!" :: LByteString)Hello, world!
Since: relude-0.3.0
putLBS :: MonadIO m => LByteString -> m () #
Lifted version of putStr.
>>>putLBS ("Hello, world!" :: LByteString)Hello, world!
Since: relude-0.3.0
putBSLn :: MonadIO m => ByteString -> m () #
Lifted version of putStrLn.
>>>putBSLn ("Hello, world!" :: ByteString)Hello, world!
Since: relude-0.3.0
putBS :: MonadIO m => ByteString -> m () #
Lifted version of putStr.
>>>putBS ("Hello, world!" :: ByteString)Hello, world!
Since: relude-0.3.0
putLTextLn :: MonadIO m => LText -> m () #
Lifted version of putStrLn.
>>>putLTextLn "Hello, world!"Hello, world!
putLText :: MonadIO m => LText -> m () #
Lifted version of putStr.
>>>putLText "Hello, world!"Hello, world!
putTextLn :: MonadIO m => Text -> m () #
Lifted version of putStrLn.
>>>putTextLn "Hello, world!"Hello, world!
putText :: MonadIO m => Text -> m () #
Lifted version of putStr.
>>>putText "Hello, world!"Hello, world!
fromStrict :: LazyStrict l s => s -> l #
Alias for toLazy function.
fromLazy :: LazyStrict l s => l -> s #
Alias for toStrict function.
show :: forall b a. (Show a, IsString b) => a -> b #
Generalized version of show. Unlike show this function
is polymorphic in its result type. This makes it more convenient to work with
data types like Text or ByteString. However, if you
pass the result of show to a function that expects polymorphic argument, this
can break type inference, so use -XTypeApplications to specify the textual
type explicitly.
>>>show (42 :: Int)"42">>>show (42 :: Double)"42.0">>>print (show @Text True)"True"
readEither :: Read a => String -> Either Text a #
Version of readEither that returns Text in case of the parse
error.
>>>readEither @Int "123"Right 123>>>readEither @Int "aa"Left "Prelude.read: no parse"
type LByteString = ByteString #
Type synonym for ByteString.
class ConvertUtf8 a b where #
Type class for conversion to utf8 representation of text.
Methods
encodeUtf8 :: a -> b #
Encode as utf8 string (usually ByteString).
>>>encodeUtf8 @Text @ByteString "патак""\208\191\208\176\209\130\208\176\208\186"
decodeUtf8 :: b -> a #
Decode from utf8 string.
>>>decodeUtf8 @Text @ByteString "\208\191\208\176\209\130\208\176\208\186""\1087\1072\1090\1072\1082">>>putTextLn $ decodeUtf8 @Text @ByteString "\208\191\208\176\209\130\208\176\208\186"патак
decodeUtf8Strict :: b -> Either UnicodeException a #
Decode as utf8 string but returning execption if byte sequence is malformed.
>>>decodeUtf8 @Text @ByteString "\208\208\176\209\130\208\176\208\186""\65533\1072\1090\1072\1082"
>>>decodeUtf8Strict @Text @ByteString "\208\208\176\209\130\208\176\208\186"Left Cannot decode byte '\xd0': ...: Invalid UTF-8 stream
Instances
Type class for converting other strings to Text.
Instances
| EncodingError ToText "ByteString" "Text" => ToText ByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toText :: ByteString -> Text # | |
| EncodingError ToText "ShortByteString" "Text" => ToText ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toText :: ShortByteString -> Text # | |
| ToText Path Source # | |
| EncodingError ToText "LByteString" "Text" => ToText LByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toText :: LByteString -> Text # | |
| ToText LText | |
Defined in Relude.String.Conversion | |
| ToText Text | |
Defined in Relude.String.Conversion | |
| ToText String | |
Defined in Relude.String.Conversion | |
Type class for converting other strings to Text.
Instances
| EncodingError ToLText "ByteString" "LText" => ToLText ByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toLText :: ByteString -> LText # | |
| EncodingError ToLText "ShortByteString" "LText" => ToLText ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toLText :: ShortByteString -> LText # | |
| EncodingError ToLText "LByteString" "LText" => ToLText LByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toLText :: LByteString -> LText # | |
| ToLText Text | |
Defined in Relude.String.Conversion | |
| ToLText Text | |
Defined in Relude.String.Conversion | |
| ToLText String | |
Defined in Relude.String.Conversion | |
Type class for converting other strings to String.
Instances
| EncodingError ToString "ByteString" "String" => ToString ByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toString :: ByteString -> String # | |
| EncodingError ToString "ShortByteString" "String" => ToString ShortByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toString :: ShortByteString -> String # | |
| ToString VarName Source # | |
Defined in Nix.Expr.Types | |
| ToString NOpName Source # | |
Defined in Nix.Parser | |
| EncodingError ToString "LByteString" "String" => ToString LByteString | ⚠️CAUTION⚠️ This instance is for custom error display only. You should always specify encoding of bytes explicitly. In case it is used by mistake, the user will see the following:
Since: relude-0.6.0.0 |
Defined in Relude.String.Conversion Methods toString :: LByteString -> String # | |
| ToString LText | |
Defined in Relude.String.Conversion | |
| ToString Text | |
Defined in Relude.String.Conversion | |
| ToString String | |
Defined in Relude.String.Conversion | |
class LazyStrict l s | l -> s, s -> l where #
Type class for lazy-strict conversions.
Since: relude-0.1.0
Instances
unwords :: IsText t "unwords" => [t] -> t #
unwords takes list of Text values and joins them with space character.
Actual type of this function is the following:
unwords :: [Text] ->Text
but it was given a more complex type to provide friendlier compile time errors.
>>>unwords []"">>>unwords ["singleWord"]"singleWord">>>unwords ["word", "another"]"word another">>>unwords (["word", "another"] :: [String])... ... 'unwords' works with 'Text', not 'String'. Possible fixes: 1. Make sure OverloadedStrings extension is enabled. 2. Apply 'toText' to a single value. 3. Apply 'map toText' to the list value. ...>>>unwords [True, False]... ... 'unwords' works with 'Text' But given: 'Bool' ...
words :: IsText t "words" => t -> [t] #
words takes Text and splits it into the list by words.
Actual type of this function is the following:
words ::Text-> [Text]
but it was given a more complex type to provide friendlier compile time errors.
>>>words ""[]>>>words "one line"["one","line"]>>>words " >_< "[">_<"]>>>words ("string words" :: String)... ... 'words' works with 'Text', not 'String'. Possible fixes: 1. Make sure OverloadedStrings extension is enabled. 2. Apply 'toText' to a single value. 3. Apply 'map toText' to the list value. ...>>>words True... ... 'words' works with 'Text' But given: 'Bool' ...
unlines :: IsText t "unlines" => [t] -> t #
unlines takes list of Text values and joins them with line separator.
Actual type of this function is the following:
unlines :: [Text] ->Text
but it was given a more complex type to provide friendlier compile time errors.
>>>unlines []"">>>unlines ["line 1"]"line 1\n">>>unlines ["first line", "second line"]"first line\nsecond line\n">>>unlines (["line 1", "line 2"] :: [String])... ... 'unlines' works with 'Text', not 'String'. Possible fixes: 1. Make sure OverloadedStrings extension is enabled. 2. Apply 'toText' to a single value. 3. Apply 'map toText' to the list value. ...>>>unlines [True, False]... ... 'unlines' works with 'Text' But given: 'Bool' ...
lines :: IsText t "lines" => t -> [t] #
lines takes Text and splits it into the list by lines.
Actual type of this function is the following:
lines ::Text-> [Text]
but it was given a more complex type to provide friendlier compile time errors.
>>>lines ""[]>>>lines "one line"["one line"]>>>lines "line 1\nline 2"["line 1","line 2"]>>>lines ("string line" :: String)... ... 'lines' works with 'Text', not 'String'. Possible fixes: 1. Make sure OverloadedStrings extension is enabled. 2. Apply 'toText' to a single value. 3. Apply 'map toText' to the list value. ...>>>lines True... ... 'lines' works with 'Text' But given: 'Bool' ...
unstableNub :: Hashable a => [a] -> [a] #
Like hashNub runs in \( O(n \log_{16} n) \) but has better performance; it doesn't save the order.
>>>unstableNub [3, 3, 3, 2, 2, -1, 1][1,2,3,-1]
sortNub :: Ord a => [a] -> [a] #
Like ordNub runs in \( O(n \log n) \) but also sorts a list.
>>>sortNub [3, 3, 3, 2, 2, -1, 1][-1,1,2,3]
ordNubOn :: Ord b => (a -> b) -> [a] -> [a] #
Similar to ordNub but performs nub through the mapped list on the given
function.
>>>ordNubOn (`div` 10) [3, 3, 3, 13, 2, 22, -1, 1, 66][3,13,22,-1,66]
Since: relude-1.0.0.0
memptyIfTrue :: Monoid m => Bool -> m -> m #
memptyIfFalse :: Monoid m => Bool -> m -> m #
maybeToMonoid :: Monoid m => Maybe m -> m #
hoistEither :: forall (m :: Type -> Type) e a. Applicative m => Either e a -> ExceptT e m a #
hoistMaybe :: forall (m :: Type -> Type) a. Applicative m => Maybe a -> MaybeT m a #
executingState :: s -> State s a -> s #
Alias for flip execState. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
executingStateT :: Functor f => s -> StateT s f a -> f s #
Alias for flip execStateT. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
evaluatingState :: s -> State s a -> a #
Alias for flip evalState. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
evaluatingStateT :: Functor f => s -> StateT s f a -> f a #
Alias for flip evalStateT. It's not shorter but sometimes
more readable. Done by analogy with using* functions family.
usingState :: s -> State s a -> (a, s) #
Shorter and more readable alias for flip runState.
usingStateT :: s -> StateT s m a -> m (a, s) #
Shorter and more readable alias for flip runStateT.
>>>usingStateT 0 $ put 42 >> pure False(False,42)
etaReaderT :: forall r (m :: Type -> Type) a. ReaderT r m a -> ReaderT r m a #
This function helps with optimizing performance when working with
the ReaderT transformer. If you have code like below, that is
called in a loop
step :: Instruction -> ReaderT Config IO Result
step instruction = case instruction of
Add -> do stuff ...
Del -> do stuff ...
you can improve performance of your Haskell applications by using
etaReaderT in the following way:
step :: Instruction ->ReaderTConfig IO Result step instruction =etaReaderT$ case instruction of Add -> do stuff ... Del -> do stuff ...
For a detailed explanation, refer to the following blog post:
Since: relude-0.7.0.0
usingReader :: r -> Reader r a -> a #
Shorter and more readable alias for flip runReader.
>>>usingReader 42 $ asks (+5)47
usingReaderT :: r -> ReaderT r m a -> m a #
Shorter and more readable alias for flip runReaderT.
>>>usingReaderT 42 $ asks (+5)47
mapMaybeM :: Monad m => (a -> m (Maybe b)) -> [a] -> m [b] #
The monadic version of the mapMaybe function.
>>>:{evenInHalf :: Int -> IO (Maybe Int) evenInHalf n | even n = pure $ Just $ n `div` 2 | otherwise = pure Nothing :}
>>>mapMaybeM evenInHalf [1..10][1,2,3,4,5]
Since: relude-0.6.0.0
whenNothingM_ :: Monad m => m (Maybe a) -> m () -> m () #
Monadic version of whenNothing_.
>>>whenNothingM_ (pure $ Just True) $ putTextLn "Is Just!">>>whenNothingM_ (pure Nothing) $ putTextLn "Is Nothing!"Is Nothing!
whenNothingM :: Monad m => m (Maybe a) -> m a -> m a #
Monadic version of whenNothing.
>>>whenNothingM (pure $ Just True) $ True <$ putTextLn "Is Just!"True>>>whenNothingM (pure Nothing) $ False <$ putTextLn "Is Nothing!"Is Nothing! False
whenNothing_ :: Applicative f => Maybe a -> f () -> f () #
Performs default Applicative action if Nothing is given.
Do nothing for Just. Convenient for discarding Just content.
>>>whenNothing_ Nothing $ putTextLn "Nothing!"Nothing!>>>whenNothing_ (Just True) $ putTextLn "Nothing!"
whenJustM :: Monad m => m (Maybe a) -> (a -> m ()) -> m () #
Monadic version of whenJust.
>>>whenJustM (pure Nothing) $ \b -> print (not b)>>>whenJustM (pure $ Just True) $ \b -> print (not b)False
(?:) :: Maybe a -> a -> a infixr 0 #
Similar to fromMaybe but with flipped arguments.
>>>readMaybe "True" ?: FalseTrue
>>>readMaybe "Tru" ?: FalseFalse
Creates an infinite list from a finite list by appending the list
to itself infinite times (i.e. by cycling the list). Unlike cycle
from Data.List, this implementation doesn't throw error on empty
lists, but returns an empty list instead.
>>>cycle [][]>>>take 10 $ cycle [1,2,3][1,2,3,1,2,3,1,2,3,1]
atomicWriteIORef :: MonadIO m => IORef a -> a -> m () #
Lifted version of atomicWriteIORef.
>>>ref <- newIORef 42>>>atomicWriteIORef ref 45>>>readIORef ref45
atomicModifyIORef'_ :: MonadIO m => IORef a -> (a -> a) -> m () #
Version of atomicModifyIORef' that discards return value. Useful
when you want to update IORef but not interested in the returning
result.
>>>ref <- newIORef 42>>>atomicModifyIORef'_ ref (`div` 2)>>>readIORef ref21
Since: relude-0.7.0.0
atomicModifyIORef_ :: MonadIO m => IORef a -> (a -> a) -> m () #
Version of atomicModifyIORef that discards return value. Useful
when you want to update IORef but not interested in the returning
result.
>>>ref <- newIORef 42>>>atomicModifyIORef_ ref (`div` 2)>>>readIORef ref21
Since: relude-0.7.0.0
atomicModifyIORef' :: MonadIO m => IORef a -> (a -> (a, b)) -> m b #
Lifted version of atomicModifyIORef'.
>>>ref <- newIORef 42>>>atomicModifyIORef' ref (\a -> (a, a + 3))45>>>readIORef ref42
- For lazier updates, see
atomicModifyIORef - If you are not interested in the return value, see
atomicModifyIORef'_
atomicModifyIORef :: MonadIO m => IORef a -> (a -> (a, b)) -> m b #
Lifted version of atomicModifyIORef.
>>>ref <- newIORef 42>>>atomicModifyIORef ref (\a -> (a, a + 3))45>>>readIORef ref42
- To avoid space-leaks, see
atomicModifyIORef'for stricter updates - If you are not interested in the return value, see
atomicModifyIORef_
modifyIORef' :: MonadIO m => IORef a -> (a -> a) -> m () #
Lifted version of modifyIORef'.
>>>ref <- newIORef 42>>>modifyIORef' ref (\a -> a + 3)>>>readIORef ref45
- For lazier updates, see
modifyIORef - For atomic updates, see
atomicModifyIORef'
modifyIORef :: MonadIO m => IORef a -> (a -> a) -> m () #
Lifted version of modifyIORef.
>>>ref <- newIORef 42>>>modifyIORef ref (\a -> a + 6)>>>readIORef ref48
- To avoid space-leaks, see
modifyIORef'for stricter updates - For atomic updates, see
atomicModifyIORef
writeIORef :: MonadIO m => IORef a -> a -> m () #
Lifted version of writeIORef.
>>>ref <- newIORef 42>>>writeIORef ref 43>>>readIORef ref43
readIORef :: MonadIO m => IORef a -> m a #
Lifted version of readIORef.
>>>ref <- newIORef 42>>>readIORef ref42
newIORef :: MonadIO m => a -> m (IORef a) #
Lifted version of newIORef.
>>>ref <- newIORef False>>>:t refref :: IORef Bool
die :: MonadIO m => String -> m a #
Lifted version of die.
>>>die "Goodbye!"Goodbye! *** Exception: ExitFailure 1
exitSuccess :: MonadIO m => m a #
Lifted version of exitSuccess.
>>>exitSuccess*** Exception: ExitSuccess
exitFailure :: MonadIO m => m a #
Lifted version of exitFailure.
>>>exitFailure*** Exception: ExitFailure 1
exitWith :: MonadIO m => ExitCode -> m a #
Lifted version of exitWith.
>>>exitWith (ExitFailure 3)*** Exception: ExitFailure 3
>>>exitWith ExitSuccess*** Exception: ExitSuccess
inverseMap :: (Bounded a, Enum a, Ord k) => (a -> k) -> k -> Maybe a #
inverseMap f creates a function that is the inverse of a given function
f. It does so by constructing Map internally for each value f a. The
implementation makes sure that the Map is constructed only once and then
shared for every call.
Memory usage note: don't inverse functions that have types like Int
as their input. In this case the created Map will have huge size.
The complexity of reversed mapping is \(\mathcal{O}(\log n)\).
Performance note: make sure to specialize monomorphic type of your functions
that use inverseMap to avoid Map reconstruction.
One of the common inverseMap use-case is inverting the show or a show-like
function.
>>>data Color = Red | Green | Blue deriving (Show, Enum, Bounded)>>>parse = inverseMap show :: String -> Maybe Color>>>parse "Red"Just Red>>>parse "Black"Nothing
Correctness note: inverseMap expects injective function as its argument,
i.e. the function must map distinct arguments to distinct values.
Typical usage of this function looks like this:
data GhcVer
= Ghc802
| Ghc822
| Ghc844
| Ghc865
| Ghc881
deriving (Eq, Ord, Show, Enum, Bounded)
showGhcVer :: GhcVer -> Text
showGhcVer = \case
Ghc802 -> "8.0.2"
Ghc822 -> "8.2.2"
Ghc844 -> "8.4.4"
Ghc865 -> "8.6.5"
Ghc881 -> "8.8.1"
parseGhcVer :: Text -> Maybe GhcVer
parseGhcVer = inverseMap showGhcVer
Since: relude-0.1.1
universeNonEmpty :: (Bounded a, Enum a) => NonEmpty a #
Like universe, but returns NonEmpty list of some enumeration
>>>universeNonEmpty :: NonEmpty BoolFalse :| [True]
>>>universeNonEmpty @OrderingLT :| [EQ,GT]
>>>data TrafficLight = Red | Blue | Green deriving (Show, Eq, Enum, Bounded)>>>universeNonEmpty :: NonEmpty TrafficLightRed :| [Blue,Green]
>>>data Singleton = Singleton deriving (Show, Eq, Enum, Bounded)>>>universeNonEmpty @SingletonSingleton :| []
Since: relude-0.7.0.0
universe :: (Bounded a, Enum a) => [a] #
Returns all values of some Bounded Enum in ascending order.
>>>universe :: [Bool][False,True]
>>>universe @Ordering[LT,EQ,GT]
>>>data TrafficLight = Red | Blue | Green deriving (Show, Enum, Bounded)>>>universe :: [TrafficLight][Red,Blue,Green]
>>>data Singleton = Singleton deriving (Show, Enum, Bounded)>>>universe @Singleton[Singleton]
Since: relude-0.1.0
(??) :: Functor f => f (a -> b) -> a -> f b infixl 4 #
Operator version of the flap function.
>>>[(+2), (*3)] ?? 5[7,15]
>>>Just (+3) ?? 5Just 8
Since: relude-0.3.0
flap :: Functor f => f (a -> b) -> a -> f b #
Takes a function in a Functor context and applies it to a normal value.
>>>flap (++) "relude" "P""Prelude"
Since: relude-0.3.0
(<<$>>) :: (Functor f, Functor g) => (a -> b) -> f (g a) -> f (g b) infixl 4 #
Alias for fmap . fmap. Convenient to work with two nested Functors.
>>>negate <<$>> Just [1,2,3]Just [-1,-2,-3]
appliedTo :: Applicative f => f a -> f (a -> b) -> f b #
Named version of the <**> operator, which is <*> but flipped. It is
helpful for chaining applicative operations in forward applications using
&.
>>>Just (+ 1) & appliedTo (Just 2)Just 3>>>Just (+) & appliedTo (Just 1) & appliedTo (Just 2)Just 3>>>Nothing & appliedTo (Just 2)Nothing
Since: relude-0.5.0
A set of values. A set cannot contain duplicate values.
Instances
| ToJSON1 HashSet | |
Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a -> Value) -> ([a] -> Value) -> HashSet a -> Value # liftToJSONList :: (a -> Value) -> ([a] -> Value) -> [HashSet a] -> Value # liftToEncoding :: (a -> Encoding) -> ([a] -> Encoding) -> HashSet a -> Encoding # liftToEncodingList :: (a -> Encoding) -> ([a] -> Encoding) -> [HashSet a] -> Encoding # | |
| Foldable HashSet | |
Defined in Data.HashSet.Internal Methods fold :: Monoid m => HashSet m -> m # foldMap :: Monoid m => (a -> m) -> HashSet a -> m # foldMap' :: Monoid m => (a -> m) -> HashSet a -> m # foldr :: (a -> b -> b) -> b -> HashSet a -> b # foldr' :: (a -> b -> b) -> b -> HashSet a -> b # foldl :: (b -> a -> b) -> b -> HashSet a -> b # foldl' :: (b -> a -> b) -> b -> HashSet a -> b # foldr1 :: (a -> a -> a) -> HashSet a -> a # foldl1 :: (a -> a -> a) -> HashSet a -> a # elem :: Eq a => a -> HashSet a -> Bool # maximum :: Ord a => HashSet a -> a # minimum :: Ord a => HashSet a -> a # | |
| Eq1 HashSet | |
| Ord1 HashSet | |
Defined in Data.HashSet.Internal | |
| Show1 HashSet | |
| NFData1 HashSet | Since: unordered-containers-0.2.14.0 |
Defined in Data.HashSet.Internal | |
| Hashable1 HashSet | |
Defined in Data.HashSet.Internal | |
| Lift a => Lift (HashSet a :: TYPE LiftedRep) | Since: unordered-containers-0.2.17.0 |
| (Eq a, Hashable a, FromJSON a) => FromJSON (HashSet a) | |
| ToJSON a => ToJSON (HashSet a) | |
Defined in Data.Aeson.Types.ToJSON | |
| (Data a, Eq a, Hashable a) => Data (HashSet a) | |
Defined in Data.HashSet.Internal Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> HashSet a -> c (HashSet a) # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (HashSet a) # toConstr :: HashSet a -> Constr # dataTypeOf :: HashSet a -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (HashSet a)) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (HashSet a)) # gmapT :: (forall b. Data b => b -> b) -> HashSet a -> HashSet a # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> HashSet a -> r # gmapQ :: (forall d. Data d => d -> u) -> HashSet a -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> HashSet a -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> HashSet a -> m (HashSet a) # | |
| (Hashable a, Eq a) => Monoid (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| (Hashable a, Eq a) => Semigroup (HashSet a) | \(O(n+m)\) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| (Eq a, Hashable a) => IsList (HashSet a) | |
| (Eq a, Hashable a, Read a) => Read (HashSet a) | |
| Show a => Show (HashSet a) | |
| NFData a => NFData (HashSet a) | |
Defined in Data.HashSet.Internal | |
| Eq a => Eq (HashSet a) | Note that, in the presence of hash collisions, equal
In general, the lack of substitutivity can be observed with any function that depends on the key ordering, such as folds and traversals. |
| Ord a => Ord (HashSet a) | |
| Hashable a => Hashable (HashSet a) | |
Defined in Data.HashSet.Internal | |
| Hashable a => One (HashSet a) | Create singleton
law> |
| Hashable a => StaticMap (HashSet a) | Since: relude-0.1.0 |
| (Serialise a, Hashable a, Eq a) => Serialise (HashSet a) | Since: serialise-0.2.0.0 |
| Monad m => MonadWriter (HashSet StringContext) (WithStringContextT m) Source # | |
Defined in Nix.String Methods writer :: (a, HashSet StringContext) -> WithStringContextT m a # tell :: HashSet StringContext -> WithStringContextT m () # listen :: WithStringContextT m a -> WithStringContextT m (a, HashSet StringContext) # pass :: WithStringContextT m (a, HashSet StringContext -> HashSet StringContext) -> WithStringContextT m a # | |
| type Item (HashSet a) | |
Defined in Data.HashSet.Internal | |
| type OneItem (HashSet a) | |
Defined in Relude.Container.One | |
| type Key (HashSet a) | |
Defined in Relude.Extra.Map | |
| type Val (HashSet a) | |
Defined in Relude.Extra.Map | |
lenientDecode :: OnDecodeError #
Replace an invalid input byte with the Unicode replacement character U+FFFD.
strictDecode :: OnDecodeError #
Throw a UnicodeException if decoding fails.
type OnDecodeError = OnError Word8 Char #
A handler for a decoding error.
type OnError a b = String -> Maybe a -> Maybe b #
Function type for handling a coding error. It is supplied with two inputs:
- A
Stringthat describes the error. - The input value that caused the error. If the error arose
because the end of input was reached or could not be identified
precisely, this value will be
Nothing.
If the handler returns a value wrapped with Just, that value will
be used in the output as the replacement for the invalid input. If
it returns Nothing, no value will be used in the output.
Should the handler need to abort processing, it should use error
or throw an exception (preferably a UnicodeException). It may
use the description provided to construct a more helpful error
report.
data UnicodeException #
An exception type for representing Unicode encoding errors.
Instances
| Exception UnicodeException | |
Defined in Data.Text.Encoding.Error Methods toException :: UnicodeException -> SomeException # | |
| Show UnicodeException | |
Defined in Data.Text.Encoding.Error Methods showsPrec :: Int -> UnicodeException -> ShowS # show :: UnicodeException -> String # showList :: [UnicodeException] -> ShowS # | |
| NFData UnicodeException | |
Defined in Data.Text.Encoding.Error Methods rnf :: UnicodeException -> () # | |
| Eq UnicodeException | |
Defined in Data.Text.Encoding.Error Methods (==) :: UnicodeException -> UnicodeException -> Bool # (/=) :: UnicodeException -> UnicodeException -> Bool # | |
decodeUtf8' :: ByteString -> Either UnicodeException Text #
Decode a ByteString containing UTF-8 encoded text.
If the input contains any invalid UTF-8 data, the relevant exception will be returned, otherwise the decoded text.
decodeUtf8With :: OnDecodeError -> ByteString -> Text #
Decode a ByteString containing UTF-8 encoded text.
NOTE: The replacement character returned by OnDecodeError
MUST be within the BMP plane; surrogate code points will
automatically be remapped to the replacement char U+FFFD
(since 0.11.3.0), whereas code points beyond the BMP will throw an
error (since 1.2.3.1); For earlier versions of text using
those unsupported code points would result in undefined behavior.
newEmptyTMVar :: STM (TMVar a) #
Create a TMVar which is initially empty.
tryPutTMVar :: TMVar a -> a -> STM Bool #
tryReadTMVar :: TMVar a -> STM (Maybe a) #
A version of readTMVar which does not retry. Instead it
returns Nothing if no value is available.
Since: stm-2.3
tryTakeTMVar :: TMVar a -> STM (Maybe a) #
A version of takeTMVar that does not retry. The tryTakeTMVar
function returns Nothing if the TMVar was empty, or Just aTMVar was full with contents a. After tryTakeTMVar, the
TMVar is left empty.
A TMVar is a synchronising variable, used
for communication between concurrent threads. It can be thought of
as a box, which may be empty or full.
modifyTVar' :: TVar a -> (a -> a) -> STM () #
Strict version of modifyTVar.
Since: stm-2.3