base-4.18.1.0: Basic libraries
Copyright(c) The University of Glasgow 2001
LicenseBSD-style (see the file libraries/base/LICENSE)
Maintainerlibraries@haskell.org
Stabilitystable
Portabilityportable
Safe HaskellTrustworthy
LanguageHaskell2010

Prelude

Description

The Prelude: a standard module. The Prelude is imported by default into all Haskell modules unless either there is an explicit import statement for it, or the NoImplicitPrelude extension is enabled.

Synopsis

Standard types, classes and related functions

Basic data types

data Bool Source #

Constructors

False 
True 

Instances

Instances details
Data Bool Source #

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Bool -> c Bool Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Bool Source #

toConstr :: Bool -> Constr Source #

dataTypeOf :: Bool -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Bool) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Bool) Source #

gmapT :: (forall b. Data b => b -> b) -> Bool -> Bool Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Bool -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Bool -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Bool -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Bool -> m Bool Source #

Storable Bool Source #

Since: base-2.1

Instance details

Defined in Foreign.Storable

Bits Bool Source #

Interpret Bool as 1-bit bit-field

Since: base-4.7.0.0

Instance details

Defined in GHC.Bits

FiniteBits Bool Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Bits

Bounded Bool Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Enum Bool Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Generic Bool Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep Bool :: Type -> Type Source #

Methods

from :: Bool -> Rep Bool x Source #

to :: Rep Bool x -> Bool Source #

Ix Bool Source #

Since: base-2.1

Instance details

Defined in GHC.Ix

Read Bool Source #

Since: base-2.1

Instance details

Defined in GHC.Read

Show Bool Source #

Since: base-2.1

Instance details

Defined in GHC.Show

Eq Bool 
Instance details

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool Source #

(/=) :: Bool -> Bool -> Bool Source #

Ord Bool 
Instance details

Defined in GHC.Classes

type Rep Bool Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep Bool = D1 ('MetaData "Bool" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "False" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "True" 'PrefixI 'False) (U1 :: Type -> Type))

(&&) :: Bool -> Bool -> Bool infixr 3 Source #

Boolean "and", lazy in the second argument

(||) :: Bool -> Bool -> Bool infixr 2 Source #

Boolean "or", lazy in the second argument

not :: Bool -> Bool Source #

Boolean "not"

otherwise :: Bool Source #

otherwise is defined as the value True. It helps to make guards more readable. eg.

 f x | x < 0     = ...
     | otherwise = ...

data Maybe a Source #

The Maybe type encapsulates an optional value. A value of type Maybe a either contains a value of type a (represented as Just a), or it is empty (represented as Nothing). 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.

Constructors

Nothing 
Just a 

Instances

Instances details
MonadFail Maybe Source #

Since: base-4.9.0.0

Instance details

Defined in Control.Monad.Fail

Methods

fail :: String -> Maybe a Source #

MonadFix Maybe Source #

Since: base-2.1

Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Maybe a) -> Maybe a Source #

MonadZip Maybe Source #

Since: base-4.8.0.0

Instance details

Defined in Control.Monad.Zip

Methods

mzip :: Maybe a -> Maybe b -> Maybe (a, b) Source #

mzipWith :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c Source #

munzip :: Maybe (a, b) -> (Maybe a, Maybe b) Source #

Foldable Maybe Source #

Since: base-2.1

Instance details

Defined in Data.Foldable

Methods

fold :: Monoid m => Maybe m -> m Source #

foldMap :: Monoid m => (a -> m) -> Maybe a -> m Source #

foldMap' :: Monoid m => (a -> m) -> Maybe a -> m Source #

foldr :: (a -> b -> b) -> b -> Maybe a -> b Source #

foldr' :: (a -> b -> b) -> b -> Maybe a -> b Source #

foldl :: (b -> a -> b) -> b -> Maybe a -> b Source #

foldl' :: (b -> a -> b) -> b -> Maybe a -> b Source #

foldr1 :: (a -> a -> a) -> Maybe a -> a Source #

foldl1 :: (a -> a -> a) -> Maybe a -> a Source #

toList :: Maybe a -> [a] Source #

null :: Maybe a -> Bool Source #

length :: Maybe a -> Int Source #

elem :: Eq a => a -> Maybe a -> Bool Source #

maximum :: Ord a => Maybe a -> a Source #

minimum :: Ord a => Maybe a -> a Source #

sum :: Num a => Maybe a -> a Source #

product :: Num a => Maybe a -> a Source #

Eq1 Maybe Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftEq :: (a -> b -> Bool) -> Maybe a -> Maybe b -> Bool Source #

Ord1 Maybe Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftCompare :: (a -> b -> Ordering) -> Maybe a -> Maybe b -> Ordering Source #

Read1 Maybe Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Show1 Maybe Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Maybe a -> ShowS Source #

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Maybe a] -> ShowS Source #

Traversable Maybe Source #

Since: base-2.1

Instance details

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> Maybe a -> f (Maybe b) Source #

sequenceA :: Applicative f => Maybe (f a) -> f (Maybe a) Source #

mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b) Source #

sequence :: Monad m => Maybe (m a) -> m (Maybe a) Source #

Alternative Maybe Source #

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

empty :: Maybe a Source #

(<|>) :: Maybe a -> Maybe a -> Maybe a Source #

some :: Maybe a -> Maybe [a] Source #

many :: Maybe a -> Maybe [a] Source #

Applicative Maybe Source #

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

pure :: a -> Maybe a Source #

(<*>) :: Maybe (a -> b) -> Maybe a -> Maybe b Source #

liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c Source #

(*>) :: Maybe a -> Maybe b -> Maybe b Source #

(<*) :: Maybe a -> Maybe b -> Maybe a Source #

Functor Maybe Source #

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

fmap :: (a -> b) -> Maybe a -> Maybe b Source #

(<$) :: a -> Maybe b -> Maybe a Source #

Monad Maybe Source #

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

(>>=) :: Maybe a -> (a -> Maybe b) -> Maybe b Source #

(>>) :: Maybe a -> Maybe b -> Maybe b Source #

return :: a -> Maybe a Source #

MonadPlus Maybe Source #

Picks the leftmost Just value, or, alternatively, Nothing.

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

mzero :: Maybe a Source #

mplus :: Maybe a -> Maybe a -> Maybe a Source #

Generic1 Maybe Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep1 Maybe :: k -> Type Source #

Methods

from1 :: forall (a :: k). Maybe a -> Rep1 Maybe a Source #

to1 :: forall (a :: k). Rep1 Maybe a -> Maybe a Source #

Data a => Data (Maybe a) Source #

Since: base-4.0.0.0

Instance details

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) Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Maybe a) Source #

toConstr :: Maybe a -> Constr Source #

dataTypeOf :: Maybe a -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Maybe a)) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Maybe a)) Source #

gmapT :: (forall b. Data b => b -> b) -> Maybe a -> Maybe a Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Maybe a -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Maybe a -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Maybe a -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Maybe a -> m (Maybe a) Source #

Semigroup a => Monoid (Maybe a) Source #

Lift a semigroup into Maybe forming a Monoid according to http://en.wikipedia.org/wiki/Monoid: "Any semigroup S may be turned into a monoid simply by adjoining an element e not in S and defining e*e = e and e*s = s = s*e for all s ∈ S."

Since 4.11.0: constraint on inner a value generalised from Monoid to Semigroup.

Since: base-2.1

Instance details

Defined in GHC.Base

Methods

mempty :: Maybe a Source #

mappend :: Maybe a -> Maybe a -> Maybe a Source #

mconcat :: [Maybe a] -> Maybe a Source #

Semigroup a => Semigroup (Maybe a) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Methods

(<>) :: Maybe a -> Maybe a -> Maybe a Source #

sconcat :: NonEmpty (Maybe a) -> Maybe a Source #

stimes :: Integral b => b -> Maybe a -> Maybe a Source #

Generic (Maybe a) Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep (Maybe a) :: Type -> Type Source #

Methods

from :: Maybe a -> Rep (Maybe a) x Source #

to :: Rep (Maybe a) x -> Maybe a Source #

Read a => Read (Maybe a) Source #

Since: base-2.1

Instance details

Defined in GHC.Read

Show a => Show (Maybe a) Source #

Since: base-2.1

Instance details

Defined in GHC.Show

Eq a => Eq (Maybe a) Source #

Since: base-2.1

Instance details

Defined in GHC.Maybe

Methods

(==) :: Maybe a -> Maybe a -> Bool Source #

(/=) :: Maybe a -> Maybe a -> Bool Source #

Ord a => Ord (Maybe a) Source #

Since: base-2.1

Instance details

Defined in GHC.Maybe

Methods

compare :: Maybe a -> Maybe a -> Ordering Source #

(<) :: Maybe a -> Maybe a -> Bool Source #

(<=) :: Maybe a -> Maybe a -> Bool Source #

(>) :: Maybe a -> Maybe a -> Bool Source #

(>=) :: Maybe a -> Maybe a -> Bool Source #

max :: Maybe a -> Maybe a -> Maybe a Source #

min :: Maybe a -> Maybe a -> Maybe a Source #

type Rep1 Maybe Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep1 Maybe = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) Par1))
type Rep (Maybe a) Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep (Maybe a) = D1 ('MetaData "Maybe" "GHC.Maybe" "base" 'False) (C1 ('MetaCons "Nothing" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "Just" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))

maybe :: b -> (a -> b) -> Maybe a -> b Source #

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

Expand

Basic usage:

>>> maybe False odd (Just 3)
True
>>> maybe False odd Nothing
False

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
""

data Either a b Source #

The Either type represents values with two possibilities: a value of type Either a b is either Left a or Right 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

Expand

The type Either String Int is the type of values which can be either a String 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
>>> s
Left "foo"
>>> let n = Right 3 :: Either String Int
>>> n
Right 3
>>> :type s
s :: Either String Int
>>> :type n
n :: 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) s
Left "foo"
>>> fmap (*2) n
Right 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)
>>> :}
>>> parseMultiple
Right 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)
>>> :}
>>> parseMultiple
Left "parse error"

Constructors

Left a 
Right b 

Instances

Instances details
Bifoldable Either Source #

Since: base-4.10.0.0

Instance details

Defined in Data.Bifoldable

Methods

bifold :: Monoid m => Either m m -> m Source #

bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Either a b -> m Source #

bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Either a b -> c Source #

bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Either a b -> c Source #

Bifoldable1 Either Source # 
Instance details

Defined in Data.Bifoldable1

Methods

bifold1 :: Semigroup m => Either m m -> m Source #

bifoldMap1 :: Semigroup m => (a -> m) -> (b -> m) -> Either a b -> m Source #

Bifunctor Either Source #

Since: base-4.8.0.0

Instance details

Defined in Data.Bifunctor

Methods

bimap :: (a -> b) -> (c -> d) -> Either a c -> Either b d Source #

first :: (a -> b) -> Either a c -> Either b c Source #

second :: (b -> c) -> Either a b -> Either a c Source #

Bitraversable Either Source #

Since: base-4.10.0.0

Instance details

Defined in Data.Bitraversable

Methods

bitraverse :: Applicative f => (a -> f c) -> (b -> f d) -> Either a b -> f (Either c d) Source #

Eq2 Either Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Either a c -> Either b d -> Bool Source #

Ord2 Either Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Either a c -> Either b d -> Ordering Source #

Read2 Either Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Either a b) Source #

liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Either a b] Source #

liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Either a b) Source #

liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Either a b] Source #

Show2 Either Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Either a b -> ShowS Source #

liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Either a b] -> ShowS Source #

Generic1 (Either a :: Type -> Type) Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep1 (Either a) :: k -> Type Source #

Methods

from1 :: forall (a0 :: k). Either a a0 -> Rep1 (Either a) a0 Source #

to1 :: forall (a0 :: k). Rep1 (Either a) a0 -> Either a a0 Source #

MonadFix (Either e) Source #

Since: base-4.3.0.0

Instance details

Defined in Control.Monad.Fix

Methods

mfix :: (a -> Either e a) -> Either e a Source #

Foldable (Either a) Source #

Since: base-4.7.0.0

Instance details

Defined in Data.Foldable

Methods

fold :: Monoid m => Either a m -> m Source #

foldMap :: Monoid m => (a0 -> m) -> Either a a0 -> m Source #

foldMap' :: Monoid m => (a0 -> m) -> Either a a0 -> m Source #

foldr :: (a0 -> b -> b) -> b -> Either a a0 -> b Source #

foldr' :: (a0 -> b -> b) -> b -> Either a a0 -> b Source #

foldl :: (b -> a0 -> b) -> b -> Either a a0 -> b Source #

foldl' :: (b -> a0 -> b) -> b -> Either a a0 -> b Source #

foldr1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source #

foldl1 :: (a0 -> a0 -> a0) -> Either a a0 -> a0 Source #

toList :: Either a a0 -> [a0] Source #

null :: Either a a0 -> Bool Source #

length :: Either a a0 -> Int Source #

elem :: Eq a0 => a0 -> Either a a0 -> Bool Source #

maximum :: Ord a0 => Either a a0 -> a0 Source #

minimum :: Ord a0 => Either a a0 -> a0 Source #

sum :: Num a0 => Either a a0 -> a0 Source #

product :: Num a0 => Either a a0 -> a0 Source #

Eq a => Eq1 (Either a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftEq :: (a0 -> b -> Bool) -> Either a a0 -> Either a b -> Bool Source #

Ord a => Ord1 (Either a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftCompare :: (a0 -> b -> Ordering) -> Either a a0 -> Either a b -> Ordering Source #

Read a => Read1 (Either a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Either a a0) Source #

liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Either a a0] Source #

liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Either a a0) Source #

liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Either a a0] Source #

Show a => Show1 (Either a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Classes

Methods

liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Either a a0 -> ShowS Source #

liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Either a a0] -> ShowS Source #

Traversable (Either a) Source #

Since: base-4.7.0.0

Instance details

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a0 -> f b) -> Either a a0 -> f (Either a b) Source #

sequenceA :: Applicative f => Either a (f a0) -> f (Either a a0) Source #

mapM :: Monad m => (a0 -> m b) -> Either a a0 -> m (Either a b) Source #

sequence :: Monad m => Either a (m a0) -> m (Either a a0) Source #

Applicative (Either e) Source #

Since: base-3.0

Instance details

Defined in Data.Either

Methods

pure :: a -> Either e a Source #

(<*>) :: Either e (a -> b) -> Either e a -> Either e b Source #

liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c Source #

(*>) :: Either e a -> Either e b -> Either e b Source #

(<*) :: Either e a -> Either e b -> Either e a Source #

Functor (Either a) Source #

Since: base-3.0

Instance details

Defined in Data.Either

Methods

fmap :: (a0 -> b) -> Either a a0 -> Either a b Source #

(<$) :: a0 -> Either a b -> Either a a0 Source #

Monad (Either e) Source #

Since: base-4.4.0.0

Instance details

Defined in Data.Either

Methods

(>>=) :: Either e a -> (a -> Either e b) -> Either e b Source #

(>>) :: Either e a -> Either e b -> Either e b Source #

return :: a -> Either e a Source #

(Data a, Data b) => Data (Either a b) Source #

Since: base-4.0.0.0

Instance details

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) Source #

gunfold :: (forall b0 r. Data b0 => c (b0 -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Either a b) Source #

toConstr :: Either a b -> Constr Source #

dataTypeOf :: Either a b -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Either a b)) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Either a b)) Source #

gmapT :: (forall b0. Data b0 => b0 -> b0) -> Either a b -> Either a b Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Either a b -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Either a b -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Either a b -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Either a b -> m (Either a b) Source #

Semigroup (Either a b) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Either

Methods

(<>) :: Either a b -> Either a b -> Either a b Source #

sconcat :: NonEmpty (Either a b) -> Either a b Source #

stimes :: Integral b0 => b0 -> Either a b -> Either a b Source #

Generic (Either a b) Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep (Either a b) :: Type -> Type Source #

Methods

from :: Either a b -> Rep (Either a b) x Source #

to :: Rep (Either a b) x -> Either a b Source #

(Read a, Read b) => Read (Either a b) Source #

Since: base-3.0

Instance details

Defined in Data.Either

(Show a, Show b) => Show (Either a b) Source #

Since: base-3.0

Instance details

Defined in Data.Either

Methods

showsPrec :: Int -> Either a b -> ShowS Source #

show :: Either a b -> String Source #

showList :: [Either a b] -> ShowS Source #

(Eq a, Eq b) => Eq (Either a b) Source #

Since: base-2.1

Instance details

Defined in Data.Either

Methods

(==) :: Either a b -> Either a b -> Bool Source #

(/=) :: Either a b -> Either a b -> Bool Source #

(Ord a, Ord b) => Ord (Either a b) Source #

Since: base-2.1

Instance details

Defined in Data.Either

Methods

compare :: Either a b -> Either a b -> Ordering Source #

(<) :: Either a b -> Either a b -> Bool Source #

(<=) :: Either a b -> Either a b -> Bool Source #

(>) :: Either a b -> Either a b -> Bool Source #

(>=) :: Either a b -> Either a b -> Bool Source #

max :: Either a b -> Either a b -> Either a b Source #

min :: Either a b -> Either a b -> Either a b Source #

type Rep1 (Either a :: Type -> Type) Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep (Either a b) Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

either :: (a -> c) -> (b -> c) -> Either a b -> c Source #

Case analysis for the Either type. If the value is Left a, apply the first function to a; if it is Right b, apply the second function to b.

Examples

Expand

We create two values of type Either String Int, one using the Left 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) s
3
>>> either length (*2) n
6

data Ordering Source #

Constructors

LT 
EQ 
GT 

Instances

Instances details
Data Ordering Source #

Since: base-4.0.0.0

Instance details

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 Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Ordering Source #

toConstr :: Ordering -> Constr Source #

dataTypeOf :: Ordering -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Ordering) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Ordering) Source #

gmapT :: (forall b. Data b => b -> b) -> Ordering -> Ordering Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Ordering -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Ordering -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Ordering -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Ordering -> m Ordering Source #

Monoid Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Base

Semigroup Ordering Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Bounded Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Enum Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Generic Ordering Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep Ordering :: Type -> Type Source #

Ix Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Ix

Read Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Read

Show Ordering Source #

Since: base-2.1

Instance details

Defined in GHC.Show

Eq Ordering 
Instance details

Defined in GHC.Classes

Ord Ordering 
Instance details

Defined in GHC.Classes

type Rep Ordering Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

type Rep Ordering = D1 ('MetaData "Ordering" "GHC.Types" "ghc-prim" 'False) (C1 ('MetaCons "LT" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "EQ" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "GT" 'PrefixI 'False) (U1 :: Type -> Type)))

data Char Source #

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

Instances details
Data Char Source #

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Char -> c Char Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Char Source #

toConstr :: Char -> Constr Source #

dataTypeOf :: Char -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Char) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Char) Source #

gmapT :: (forall b. Data b => b -> b) -> Char -> Char Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r Source #

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Char -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Char -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Char -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Char -> m Char Source #

Storable Char Source #

Since: base-2.1

Instance details

Defined in Foreign.Storable

Bounded Char Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Enum Char Source #

Since: base-2.1

Instance details

Defined in GHC.Enum

Ix Char Source #

Since: base-2.1

Instance details

Defined in GHC.Ix

Read Char Source #

Since: base-2.1

Instance details

Defined in GHC.Read

Show Char Source #

Since: base-2.1

Instance details

Defined in GHC.Show

IsChar Char Source #

Since: base-2.1

Instance details

Defined in Text.Printf

PrintfArg Char Source #

Since: base-2.1

Instance details

Defined in Text.Printf

Eq Char 
Instance details

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool Source #

(/=) :: Char -> Char -> Bool Source #

Ord Char 
Instance details

Defined in GHC.Classes

TestCoercion SChar Source #

Since: base-4.18.0.0

Instance details

Defined in GHC.TypeLits

Methods

testCoercion :: forall (a :: k) (b :: k). SChar a -> SChar b -> Maybe (Coercion a b) Source #

TestEquality SChar Source #

Since: base-4.18.0.0

Instance details

Defined in GHC.TypeLits

Methods

testEquality :: forall (a :: k) (b :: k). SChar a -> SChar b -> Maybe (a :~: b) Source #

Generic1 (URec Char :: k -> Type) Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep1 (URec Char) :: k -> Type Source #

Methods

from1 :: forall (a :: k0). URec Char a -> Rep1 (URec Char) a Source #

to1 :: forall (a :: k0). Rep1 (URec Char) a -> URec Char a Source #

Foldable (UChar :: Type -> Type) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Foldable

Methods

fold :: Monoid m => UChar m -> m Source #

foldMap :: Monoid m => (a -> m) -> UChar a -> m Source #

foldMap' :: Monoid m => (a -> m) -> UChar a -> m Source #

foldr :: (a -> b -> b) -> b -> UChar a -> b Source #

foldr' :: (a -> b -> b) -> b -> UChar a -> b Source #

foldl :: (b -> a -> b) -> b -> UChar a -> b Source #

foldl' :: (b -> a -> b) -> b -> UChar a -> b Source #

foldr1 :: (a -> a -> a) -> UChar a -> a Source #

foldl1 :: (a -> a -> a) -> UChar a -> a Source #

toList :: UChar a -> [a] Source #

null :: UChar a -> Bool Source #

length :: UChar a -> Int Source #

elem :: Eq a => a -> UChar a -> Bool Source #

maximum :: Ord a => UChar a -> a Source #

minimum :: Ord a => UChar a -> a Source #

sum :: Num a => UChar a -> a Source #

product :: Num a => UChar a -> a Source #

Traversable (UChar :: Type -> Type) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Traversable

Methods

traverse :: Applicative f => (a -> f b) -> UChar a -> f (UChar b) Source #

sequenceA :: Applicative f => UChar (f a) -> f (UChar a) Source #

mapM :: Monad m => (a -> m b) -> UChar a -> m (UChar b) Source #

sequence :: Monad m => UChar (m a) -> m (UChar a) Source #

Functor (URec Char :: Type -> Type) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

fmap :: (a -> b) -> URec Char a -> URec Char b Source #

(<$) :: a -> URec Char b -> URec Char a Source #

Generic (URec Char p) Source # 
Instance details

Defined in GHC.Generics

Associated Types

type Rep (URec Char p) :: Type -> Type Source #

Methods

from :: URec Char p -> Rep (URec Char p) x Source #

to :: Rep (URec Char p) x -> URec Char p Source #

Show (URec Char p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Eq (URec Char p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec Char p -> URec Char p -> Bool Source #

(/=) :: URec Char p -> URec Char p -> Bool Source #

Ord (URec Char p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

compare :: URec Char p -> URec Char p -> Ordering Source #

(<) :: URec Char p -> URec Char p -> Bool Source #

(<=) :: URec Char p -> URec Char p -> Bool Source #

(>) :: URec Char p -> URec Char p -> Bool Source #

(>=) :: URec Char p -> URec Char p -> Bool Source #

max :: URec Char p -> URec Char p -> URec Char p Source #

min :: URec Char p -> URec Char p -> URec Char p Source #

data URec Char (p :: k) Source #

Used for marking occurrences of Char#

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

data URec Char (p :: k) = UChar {}
type Compare (a :: Char) (b :: Char) Source # 
Instance details

Defined in Data.Type.Ord

type Compare (a :: Char) (b :: Char) = CmpChar a b
type Rep1 (URec Char :: k -> Type) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

type Rep1 (URec Char :: k -> Type) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: k -> Type)))
type Rep (URec Char p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

type Rep (URec Char p) = D1 ('MetaData "URec" "GHC.Generics" "base" 'False) (C1 ('MetaCons "UChar" 'PrefixI 'True) (S1 ('MetaSel ('Just "uChar#") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (UChar :: Type -> Type)))

type String = [Char] Source #

A String is a list of characters. String constants in Haskell are values of type String.

See Data.List for operations on lists.

Tuples

fst :: (a, b) -> a Source #

Extract the first component of a pair.

snd :: (a, b) -> b Source #

Extract the second component of a pair.

curry :: ((a, b) -> c) -> a -> b -> c Source #

curry converts an uncurried function to a curried function.

Examples

Expand
>>> curry fst 1 2
1

uncurry :: (a -> b -> c) -> (a, b) -> c Source #

uncurry converts a curried function to a function on pairs.

Examples

Expand
>>> uncurry (+) (1,2)
3
>>> uncurry ($) (show, 1)
"1"
>>> map (uncurry max) [(1,2), (3,4), (6,8)]
[2,4,8]

Basic type classes

class Eq a where Source #

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:

Reflexivity
x == x = True
Symmetry
x == y = y == x
Transitivity
if x == y && y == z = True, then x == z = True
Extensionality
if x == y = True and f is a function whose return type is an instance of Eq, then f x == f y = True
Negation
x /= y = not (x == y)

Minimal complete definition: either == or /=.

Minimal complete definition

(==) | (/=)

Methods

(==) :: a -> a -> Bool infix 4 Source #

(/=) :: a -> a -> Bool infix 4 Source #

Instances

Instances details
Eq ByteArray Source #

Since: base-4.17.0.0

Instance details

Defined in Data.Array.Byte

Eq Constr Source #

Equality of constructors

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Eq ConstrRep Source #

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Eq DataRep Source #

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Eq Fixity Source #

Since: base-4.0.0.0

Instance details

Defined in Data.Data

Eq All Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: All -> All -> Bool Source #

(/=) :: All -> All -> Bool Source #

Eq Any Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: Any -> Any -> Bool Source #

(/=) :: Any -> Any -> Bool Source #

Eq SomeTypeRep Source # 
Instance details

Defined in Data.Typeable.Internal

Eq Unique Source # 
Instance details

Defined in Data.Unique

Eq Version Source #

Since: base-2.1

Instance details

Defined in Data.Version

Eq Errno Source #

Since: base-2.1

Instance details

Defined in Foreign.C.Error

Methods

(==) :: Errno -> Errno -> Bool Source #

(/=) :: Errno -> Errno -> Bool Source #

Eq CBool Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CBool -> CBool -> Bool Source #

(/=) :: CBool -> CBool -> Bool Source #

Eq CChar Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CChar -> CChar -> Bool Source #

(/=) :: CChar -> CChar -> Bool Source #

Eq CClock Source # 
Instance details

Defined in Foreign.C.Types

Eq CDouble Source # 
Instance details

Defined in Foreign.C.Types

Eq CFloat Source # 
Instance details

Defined in Foreign.C.Types

Eq CInt Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CInt -> CInt -> Bool Source #

(/=) :: CInt -> CInt -> Bool Source #

Eq CIntMax Source # 
Instance details

Defined in Foreign.C.Types

Eq CIntPtr Source # 
Instance details

Defined in Foreign.C.Types

Eq CLLong Source # 
Instance details

Defined in Foreign.C.Types

Eq CLong Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CLong -> CLong -> Bool Source #

(/=) :: CLong -> CLong -> Bool Source #

Eq CPtrdiff Source # 
Instance details

Defined in Foreign.C.Types

Eq CSChar Source # 
Instance details

Defined in Foreign.C.Types

Eq CSUSeconds Source # 
Instance details

Defined in Foreign.C.Types

Eq CShort Source # 
Instance details

Defined in Foreign.C.Types

Eq CSigAtomic Source # 
Instance details

Defined in Foreign.C.Types

Eq CSize Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CSize -> CSize -> Bool Source #

(/=) :: CSize -> CSize -> Bool Source #

Eq CTime Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CTime -> CTime -> Bool Source #

(/=) :: CTime -> CTime -> Bool Source #

Eq CUChar Source # 
Instance details

Defined in Foreign.C.Types

Eq CUInt Source # 
Instance details

Defined in Foreign.C.Types

Methods

(==) :: CUInt -> CUInt -> Bool Source #

(/=) :: CUInt -> CUInt -> Bool Source #

Eq CUIntMax Source # 
Instance details

Defined in Foreign.C.Types

Eq CUIntPtr Source # 
Instance details

Defined in Foreign.C.Types

Eq CULLong Source # 
Instance details

Defined in Foreign.C.Types

Eq CULong Source # 
Instance details

Defined in Foreign.C.Types

Eq CUSeconds Source # 
Instance details

Defined in Foreign.C.Types

Eq CUShort Source # 
Instance details

Defined in Foreign.C.Types

Eq CWchar Source # 
Instance details

Defined in Foreign.C.Types

Eq IntPtr Source # 
Instance details

Defined in Foreign.Ptr

Eq WordPtr Source # 
Instance details

Defined in Foreign.Ptr

Eq Void Source #

Since: base-4.8.0.0

Instance details

Defined in GHC.Base

Methods

(==) :: Void -> Void -> Bool Source #

(/=) :: Void -> Void -> Bool Source #

Eq ByteOrder Source #

Since: base-4.11.0.0

Instance details

Defined in GHC.ByteOrder

Eq BlockReason Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Eq ThreadId Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.Conc.Sync

Eq ThreadStatus Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Eq Event Source #

Since: base-4.4.0.0

Instance details

Defined in GHC.Event.Internal.Types

Methods

(==) :: Event -> Event -> Bool Source #

(/=) :: Event -> Event -> Bool Source #

Eq Lifetime Source #

Since: base-4.8.1.0

Instance details

Defined in GHC.Event.Internal.Types

Eq FdKey Source #

Since: base-4.4.0.0

Instance details

Defined in GHC.Event.Manager

Methods

(==) :: FdKey -> FdKey -> Bool Source #

(/=) :: FdKey -> FdKey -> Bool Source #

Eq TimeoutKey Source # 
Instance details

Defined in GHC.Event.TimeOut

Eq ErrorCall Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Exception

Eq ArithException Source #

Since: base-3.0

Instance details

Defined in GHC.Exception.Type

Eq SpecConstrAnnotation Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.Exts

Eq Fingerprint Source #

Since: base-4.4.0.0

Instance details

Defined in GHC.Fingerprint.Type

Eq Associativity Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

Eq DecidedStrictness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Eq Fixity Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

Eq SourceStrictness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Eq SourceUnpackedness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Eq MaskingState Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.IO

Eq BufferState Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Buffer

Eq IODeviceType Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Device

Eq SeekMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Device

Eq CodingProgress Source #

Since: base-4.4.0.0

Instance details

Defined in GHC.IO.Encoding.Types

Eq ArrayException Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Exception

Eq AsyncException Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Exception

Eq ExitCode Source # 
Instance details

Defined in GHC.IO.Exception

Eq IOErrorType Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.IO.Exception

Eq IOException Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.IO.Exception

Eq HandlePosn Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.IO.Handle

Eq BufferMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Handle.Types

Eq Handle Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.IO.Handle.Types

Eq Newline Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Handle.Types

Eq NewlineMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Handle.Types

Eq IOMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.IOMode

Eq InfoProv Source # 
Instance details

Defined in GHC.InfoProv

Eq Int16 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Methods

(==) :: Int16 -> Int16 -> Bool Source #

(/=) :: Int16 -> Int16 -> Bool Source #

Eq Int32 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Methods

(==) :: Int32 -> Int32 -> Bool Source #

(/=) :: Int32 -> Int32 -> Bool Source #

Eq Int64 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Methods

(==) :: Int64 -> Int64 -> Bool Source #

(/=) :: Int64 -> Int64 -> Bool Source #

Eq Int8 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Methods

(==) :: Int8 -> Int8 -> Bool Source #

(/=) :: Int8 -> Int8 -> Bool Source #

Eq IoSubSystem Source # 
Instance details

Defined in GHC.RTS.Flags

Eq StackEntry Source # 
Instance details

Defined in GHC.Stack.CloneStack

Eq SrcLoc Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Stack.Types

Eq SomeChar Source # 
Instance details

Defined in GHC.TypeLits

Eq SomeSymbol Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.TypeLits

Eq SomeNat Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.TypeNats

Eq GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Unicode

Eq Word16 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Eq Word32 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Eq Word64 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Eq Word8 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Methods

(==) :: Word8 -> Word8 -> Bool Source #

(/=) :: Word8 -> Word8 -> Bool Source #

Eq CBlkCnt Source # 
Instance details

Defined in System.Posix.Types

Eq CBlkSize Source # 
Instance details

Defined in System.Posix.Types

Eq CCc Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CCc -> CCc -> Bool Source #

(/=) :: CCc -> CCc -> Bool Source #

Eq CClockId Source # 
Instance details

Defined in System.Posix.Types

Eq CDev Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CDev -> CDev -> Bool Source #

(/=) :: CDev -> CDev -> Bool Source #

Eq CFsBlkCnt Source # 
Instance details

Defined in System.Posix.Types

Eq CFsFilCnt Source # 
Instance details

Defined in System.Posix.Types

Eq CGid Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CGid -> CGid -> Bool Source #

(/=) :: CGid -> CGid -> Bool Source #

Eq CId Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CId -> CId -> Bool Source #

(/=) :: CId -> CId -> Bool Source #

Eq CIno Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CIno -> CIno -> Bool Source #

(/=) :: CIno -> CIno -> Bool Source #

Eq CKey Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CKey -> CKey -> Bool Source #

(/=) :: CKey -> CKey -> Bool Source #

Eq CMode Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CMode -> CMode -> Bool Source #

(/=) :: CMode -> CMode -> Bool Source #

Eq CNfds Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CNfds -> CNfds -> Bool Source #

(/=) :: CNfds -> CNfds -> Bool Source #

Eq CNlink Source # 
Instance details

Defined in System.Posix.Types

Eq COff Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: COff -> COff -> Bool Source #

(/=) :: COff -> COff -> Bool Source #

Eq CPid Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CPid -> CPid -> Bool Source #

(/=) :: CPid -> CPid -> Bool Source #

Eq CRLim Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CRLim -> CRLim -> Bool Source #

(/=) :: CRLim -> CRLim -> Bool Source #

Eq CSocklen Source # 
Instance details

Defined in System.Posix.Types

Eq CSpeed Source # 
Instance details

Defined in System.Posix.Types

Eq CSsize Source # 
Instance details

Defined in System.Posix.Types

Eq CTcflag Source # 
Instance details

Defined in System.Posix.Types

Eq CTimer Source # 
Instance details

Defined in System.Posix.Types

Eq CUid Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: CUid -> CUid -> Bool Source #

(/=) :: CUid -> CUid -> Bool Source #

Eq Fd Source # 
Instance details

Defined in System.Posix.Types

Methods

(==) :: Fd -> Fd -> Bool Source #

(/=) :: Fd -> Fd -> Bool Source #

Eq Timeout Source # 
Instance details

Defined in System.Timeout

Eq Lexeme Source #

Since: base-2.1

Instance details

Defined in Text.Read.Lex

Eq Number Source #

Since: base-4.6.0.0

Instance details

Defined in Text.Read.Lex

Eq BigNat 
Instance details

Defined in GHC.Num.BigNat

Eq Module 
Instance details

Defined in GHC.Classes

Eq Ordering 
Instance details

Defined in GHC.Classes

Eq TrName 
Instance details

Defined in GHC.Classes

Eq TyCon 
Instance details

Defined in GHC.Classes

Methods

(==) :: TyCon -> TyCon -> Bool Source #

(/=) :: TyCon -> TyCon -> Bool Source #

Eq Integer 
Instance details

Defined in GHC.Num.Integer

Eq Natural 
Instance details

Defined in GHC.Num.Natural

Eq () 
Instance details

Defined in GHC.Classes

Methods

(==) :: () -> () -> Bool Source #

(/=) :: () -> () -> Bool Source #

Eq Bool 
Instance details

Defined in GHC.Classes

Methods

(==) :: Bool -> Bool -> Bool Source #

(/=) :: Bool -> Bool -> Bool Source #

Eq Char 
Instance details

Defined in GHC.Classes

Methods

(==) :: Char -> Char -> Bool Source #

(/=) :: Char -> Char -> Bool Source #

Eq Double

Note that due to the presence of NaN, Double's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Double)
False

Also note that Double's Eq instance does not satisfy substitutivity:

>>> 0 == (-0 :: Double)
True
>>> recip 0 == recip (-0 :: Double)
False
Instance details

Defined in GHC.Classes

Eq Float

Note that due to the presence of NaN, Float's Eq instance does not satisfy reflexivity.

>>> 0/0 == (0/0 :: Float)
False

Also note that Float's Eq instance does not satisfy extensionality:

>>> 0 == (-0 :: Float)
True
>>> recip 0 == recip (-0 :: Float)
False
Instance details

Defined in GHC.Classes

Methods

(==) :: Float -> Float -> Bool Source #

(/=) :: Float -> Float -> Bool Source #

Eq Int 
Instance details

Defined in GHC.Classes

Methods

(==) :: Int -> Int -> Bool Source #

(/=) :: Int -> Int -> Bool Source #

Eq Word 
Instance details

Defined in GHC.Classes

Methods

(==) :: Word -> Word -> Bool Source #

(/=) :: Word -> Word -> Bool Source #

Eq a => Eq (ZipList a) Source #

Since: base-4.7.0.0

Instance details

Defined in Control.Applicative

Methods

(==) :: ZipList a -> ZipList a -> Bool Source #

(/=) :: ZipList a -> ZipList a -> Bool Source #

Eq (Chan a) Source #

Since: base-4.4.0.0

Instance details

Defined in Control.Concurrent.Chan

Methods

(==) :: Chan a -> Chan a -> Bool Source #

(/=) :: Chan a -> Chan a -> Bool Source #

Eq (MutableByteArray s) Source #

Since: base-4.17.0.0

Instance details

Defined in Data.Array.Byte

Eq a => Eq (And a) Source #

Since: base-4.16

Instance details

Defined in Data.Bits

Methods

(==) :: And a -> And a -> Bool Source #

(/=) :: And a -> And a -> Bool Source #

Eq a => Eq (Iff a) Source #

Since: base-4.16

Instance details

Defined in Data.Bits

Methods

(==) :: Iff a -> Iff a -> Bool Source #

(/=) :: Iff a -> Iff a -> Bool Source #

Eq a => Eq (Ior a) Source #

Since: base-4.16

Instance details

Defined in Data.Bits

Methods

(==) :: Ior a -> Ior a -> Bool Source #

(/=) :: Ior a -> Ior a -> Bool Source #

Eq a => Eq (Xor a) Source #

Since: base-4.16

Instance details

Defined in Data.Bits

Methods

(==) :: Xor a -> Xor a -> Bool Source #

(/=) :: Xor a -> Xor a -> Bool Source #

Eq a => Eq (Complex a) Source #

Since: base-2.1

Instance details

Defined in Data.Complex

Methods

(==) :: Complex a -> Complex a -> Bool Source #

(/=) :: Complex a -> Complex a -> Bool Source #

Eq a => Eq (Identity a) Source #

Since: base-4.8.0.0

Instance details

Defined in Data.Functor.Identity

Methods

(==) :: Identity a -> Identity a -> Bool Source #

(/=) :: Identity a -> Identity a -> Bool Source #

Eq a => Eq (First a) Source #

Since: base-2.1

Instance details

Defined in Data.Monoid

Methods

(==) :: First a -> First a -> Bool Source #

(/=) :: First a -> First a -> Bool Source #

Eq a => Eq (Last a) Source #

Since: base-2.1

Instance details

Defined in Data.Monoid

Methods

(==) :: Last a -> Last a -> Bool Source #

(/=) :: Last a -> Last a -> Bool Source #

Eq a => Eq (Down a) Source #

Since: base-4.6.0.0

Instance details

Defined in Data.Ord

Methods

(==) :: Down a -> Down a -> Bool Source #

(/=) :: Down a -> Down a -> Bool Source #

Eq a => Eq (First a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(==) :: First a -> First a -> Bool Source #

(/=) :: First a -> First a -> Bool Source #

Eq a => Eq (Last a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(==) :: Last a -> Last a -> Bool Source #

(/=) :: Last a -> Last a -> Bool Source #

Eq a => Eq (Max a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(==) :: Max a -> Max a -> Bool Source #

(/=) :: Max a -> Max a -> Bool Source #

Eq a => Eq (Min a) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(==) :: Min a -> Min a -> Bool Source #

(/=) :: Min a -> Min a -> Bool Source #

Eq m => Eq (WrappedMonoid m) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Eq a => Eq (Dual a) Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: Dual a -> Dual a -> Bool Source #

(/=) :: Dual a -> Dual a -> Bool Source #

Eq a => Eq (Product a) Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: Product a -> Product a -> Bool Source #

(/=) :: Product a -> Product a -> Bool Source #

Eq a => Eq (Sum a) Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: Sum a -> Sum a -> Bool Source #

(/=) :: Sum a -> Sum a -> Bool Source #

Eq (ConstPtr a) Source # 
Instance details

Defined in Foreign.C.ConstPtr

Methods

(==) :: ConstPtr a -> ConstPtr a -> Bool Source #

(/=) :: ConstPtr a -> ConstPtr a -> Bool Source #

Eq a => Eq (NonEmpty a) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Base

Methods

(==) :: NonEmpty a -> NonEmpty a -> Bool Source #

(/=) :: NonEmpty a -> NonEmpty a -> Bool Source #

Eq (TVar a) Source #

Since: base-4.8.0.0

Instance details

Defined in GHC.Conc.Sync

Methods

(==) :: TVar a -> TVar a -> Bool Source #

(/=) :: TVar a -> TVar a -> Bool Source #

Eq (ForeignPtr a) Source #

Since: base-2.1

Instance details

Defined in GHC.ForeignPtr

Eq p => Eq (Par1 p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: Par1 p -> Par1 p -> Bool Source #

(/=) :: Par1 p -> Par1 p -> Bool Source #

Eq (IORef a) Source #

Pointer equality.

Since: base-4.0.0.0

Instance details

Defined in GHC.IORef

Methods

(==) :: IORef a -> IORef a -> Bool Source #

(/=) :: IORef a -> IORef a -> Bool Source #

Eq (MVar a) Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.MVar

Methods

(==) :: MVar a -> MVar a -> Bool Source #

(/=) :: MVar a -> MVar a -> Bool Source #

Eq (FunPtr a) Source # 
Instance details

Defined in GHC.Ptr

Methods

(==) :: FunPtr a -> FunPtr a -> Bool Source #

(/=) :: FunPtr a -> FunPtr a -> Bool Source #

Eq (Ptr a) Source #

Since: base-2.1

Instance details

Defined in GHC.Ptr

Methods

(==) :: Ptr a -> Ptr a -> Bool Source #

(/=) :: Ptr a -> Ptr a -> Bool Source #

Eq a => Eq (Ratio a) Source #

Since: base-2.1

Instance details

Defined in GHC.Real

Methods

(==) :: Ratio a -> Ratio a -> Bool Source #

(/=) :: Ratio a -> Ratio a -> Bool Source #

Eq (StablePtr a) Source #

Since: base-2.1

Instance details

Defined in GHC.Stable

Eq (StableName a) Source #

Since: base-2.1

Instance details

Defined in GHC.StableName

Eq a => Eq (Maybe a) Source #

Since: base-2.1

Instance details

Defined in GHC.Maybe

Methods

(==) :: Maybe a -> Maybe a -> Bool Source #

(/=) :: Maybe a -> Maybe a -> Bool Source #

Eq a => Eq (a) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a) -> (a) -> Bool Source #

(/=) :: (a) -> (a) -> Bool Source #

Eq a => Eq [a] 
Instance details

Defined in GHC.Classes

Methods

(==) :: [a] -> [a] -> Bool Source #

(/=) :: [a] -> [a] -> Bool Source #

(Eq a, Eq b) => Eq (Either a b) Source #

Since: base-2.1

Instance details

Defined in Data.Either

Methods

(==) :: Either a b -> Either a b -> Bool Source #

(/=) :: Either a b -> Either a b -> Bool Source #

Eq (Fixed a) Source #

Since: base-2.1

Instance details

Defined in Data.Fixed

Methods

(==) :: Fixed a -> Fixed a -> Bool Source #

(/=) :: Fixed a -> Fixed a -> Bool Source #

Eq (Proxy s) Source #

Since: base-4.7.0.0

Instance details

Defined in Data.Proxy

Methods

(==) :: Proxy s -> Proxy s -> Bool Source #

(/=) :: Proxy s -> Proxy s -> Bool Source #

Eq a => Eq (Arg a b) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Semigroup

Methods

(==) :: Arg a b -> Arg a b -> Bool Source #

(/=) :: Arg a b -> Arg a b -> Bool Source #

Eq (TypeRep a) Source #

Since: base-2.1

Instance details

Defined in Data.Typeable.Internal

Methods

(==) :: TypeRep a -> TypeRep a -> Bool Source #

(/=) :: TypeRep a -> TypeRep a -> Bool Source #

(Ix i, Eq e) => Eq (Array i e) Source #

Since: base-2.1

Instance details

Defined in GHC.Arr

Methods

(==) :: Array i e -> Array i e -> Bool Source #

(/=) :: Array i e -> Array i e -> Bool Source #

Eq (U1 p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: U1 p -> U1 p -> Bool Source #

(/=) :: U1 p -> U1 p -> Bool Source #

Eq (V1 p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: V1 p -> V1 p -> Bool Source #

(/=) :: V1 p -> V1 p -> Bool Source #

Eq (IOArray i e) Source #

Since: base-4.1.0.0

Instance details

Defined in GHC.IOArray

Methods

(==) :: IOArray i e -> IOArray i e -> Bool Source #

(/=) :: IOArray i e -> IOArray i e -> Bool Source #

Eq (STRef s a) Source #

Pointer equality.

Since: base-2.1

Instance details

Defined in GHC.STRef

Methods

(==) :: STRef s a -> STRef s a -> Bool Source #

(/=) :: STRef s a -> STRef s a -> Bool Source #

(Eq a, Eq b) => Eq (a, b) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b) -> (a, b) -> Bool Source #

(/=) :: (a, b) -> (a, b) -> Bool Source #

Eq a => Eq (Const a b) Source #

Since: base-4.9.0.0

Instance details

Defined in Data.Functor.Const

Methods

(==) :: Const a b -> Const a b -> Bool Source #

(/=) :: Const a b -> Const a b -> Bool Source #

Eq (f a) => Eq (Ap f a) Source #

Since: base-4.12.0.0

Instance details

Defined in Data.Monoid

Methods

(==) :: Ap f a -> Ap f a -> Bool Source #

(/=) :: Ap f a -> Ap f a -> Bool Source #

Eq (f a) => Eq (Alt f a) Source #

Since: base-4.8.0.0

Instance details

Defined in Data.Semigroup.Internal

Methods

(==) :: Alt f a -> Alt f a -> Bool Source #

(/=) :: Alt f a -> Alt f a -> Bool Source #

Eq (Coercion a b) Source #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Coercion

Methods

(==) :: Coercion a b -> Coercion a b -> Bool Source #

(/=) :: Coercion a b -> Coercion a b -> Bool Source #

Eq (a :~: b) Source #

Since: base-4.7.0.0

Instance details

Defined in Data.Type.Equality

Methods

(==) :: (a :~: b) -> (a :~: b) -> Bool Source #

(/=) :: (a :~: b) -> (a :~: b) -> Bool Source #

Eq (OrderingI a b) Source # 
Instance details

Defined in Data.Type.Ord

Methods

(==) :: OrderingI a b -> OrderingI a b -> Bool Source #

(/=) :: OrderingI a b -> OrderingI a b -> Bool Source #

Eq (STArray s i e) Source #

Since: base-2.1

Instance details

Defined in GHC.Arr

Methods

(==) :: STArray s i e -> STArray s i e -> Bool Source #

(/=) :: STArray s i e -> STArray s i e -> Bool Source #

(Generic1 f, Eq (Rep1 f a)) => Eq (Generically1 f a) Source #

Since: base-4.18.0.0

Instance details

Defined in GHC.Generics

Eq (f p) => Eq (Rec1 f p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: Rec1 f p -> Rec1 f p -> Bool Source #

(/=) :: Rec1 f p -> Rec1 f p -> Bool Source #

Eq (URec (Ptr ()) p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

(/=) :: URec (Ptr ()) p -> URec (Ptr ()) p -> Bool Source #

Eq (URec Char p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec Char p -> URec Char p -> Bool Source #

(/=) :: URec Char p -> URec Char p -> Bool Source #

Eq (URec Double p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec Double p -> URec Double p -> Bool Source #

(/=) :: URec Double p -> URec Double p -> Bool Source #

Eq (URec Float p) Source # 
Instance details

Defined in GHC.Generics

Methods

(==) :: URec Float p -> URec Float p -> Bool Source #

(/=) :: URec Float p -> URec Float p -> Bool Source #

Eq (URec Int p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec Int p -> URec Int p -> Bool Source #

(/=) :: URec Int p -> URec Int p -> Bool Source #

Eq (URec Word p) Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: URec Word p -> URec Word p -> Bool Source #

(/=) :: URec Word p -> URec Word p -> Bool Source #

(Eq a, Eq b, Eq c) => Eq (a, b, c) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c) -> (a, b, c) -> Bool Source #

(/=) :: (a, b, c) -> (a, b, c) -> Bool Source #

(Eq (f a), Eq (g a)) => Eq (Product f g a) Source #

Since: base-4.18.0.0

Instance details

Defined in Data.Functor.Product

Methods

(==) :: Product f g a -> Product f g a -> Bool Source #

(/=) :: Product f g a -> Product f g a -> Bool Source #

(Eq (f a), Eq (g a)) => Eq (Sum f g a) Source #

Since: base-4.18.0.0

Instance details

Defined in Data.Functor.Sum

Methods

(==) :: Sum f g a -> Sum f g a -> Bool Source #

(/=) :: Sum f g a -> Sum f g a -> Bool Source #

Eq (a :~~: b) Source #

Since: base-4.10.0.0

Instance details

Defined in Data.Type.Equality

Methods

(==) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(/=) :: (a :~~: b) -> (a :~~: b) -> Bool Source #

(Eq (f p), Eq (g p)) => Eq ((f :*: g) p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: (f :*: g) p -> (f :*: g) p -> Bool Source #

(/=) :: (f :*: g) p -> (f :*: g) p -> Bool Source #

(Eq (f p), Eq (g p)) => Eq ((f :+: g) p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: (f :+: g) p -> (f :+: g) p -> Bool Source #

(/=) :: (f :+: g) p -> (f :+: g) p -> Bool Source #

Eq c => Eq (K1 i c p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: K1 i c p -> K1 i c p -> Bool Source #

(/=) :: K1 i c p -> K1 i c p -> Bool Source #

(Eq a, Eq b, Eq c, Eq d) => Eq (a, b, c, d) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source #

(/=) :: (a, b, c, d) -> (a, b, c, d) -> Bool Source #

Eq (f (g a)) => Eq (Compose f g a) Source #

Since: base-4.18.0.0

Instance details

Defined in Data.Functor.Compose

Methods

(==) :: Compose f g a -> Compose f g a -> Bool Source #

(/=) :: Compose f g a -> Compose f g a -> Bool Source #

Eq (f (g p)) => Eq ((f :.: g) p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: (f :.: g) p -> (f :.: g) p -> Bool Source #

(/=) :: (f :.: g) p -> (f :.: g) p -> Bool Source #

Eq (f p) => Eq (M1 i c f p) Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Generics

Methods

(==) :: M1 i c f p -> M1 i c f p -> Bool Source #

(/=) :: M1 i c f p -> M1 i c f p -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e) => Eq (a, b, c, d, e) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source #

(/=) :: (a, b, c, d, e) -> (a, b, c, d, e) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f) => Eq (a, b, c, d, e, f) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source #

(/=) :: (a, b, c, d, e, f) -> (a, b, c, d, e, f) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g) => Eq (a, b, c, d, e, f, g) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g) -> (a, b, c, d, e, f, g) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h) => Eq (a, b, c, d, e, f, g, h) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h) -> (a, b, c, d, e, f, g, h) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i) => Eq (a, b, c, d, e, f, g, h, i) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i) -> (a, b, c, d, e, f, g, h, i) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j) => Eq (a, b, c, d, e, f, g, h, i, j) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j) -> (a, b, c, d, e, f, g, h, i, j) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k) => Eq (a, b, c, d, e, f, g, h, i, j, k) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j, k) -> (a, b, c, d, e, f, g, h, i, j, k) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l) => Eq (a, b, c, d, e, f, g, h, i, j, k, l) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j, k, l) -> (a, b, c, d, e, f, g, h, i, j, k, l) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> Bool Source #

(Eq a, Eq b, Eq c, Eq d, Eq e, Eq f, Eq g, Eq h, Eq i, Eq j, Eq k, Eq l, Eq m, Eq n, Eq o) => Eq (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) 
Instance details

Defined in GHC.Classes

Methods

(==) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool Source #

(/=) :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> Bool Source #

class Eq a => Ord a where Source #

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, then x <= z = True
Reflexivity
x <= x = True
Antisymmetry
if x <= y && y <= x = True, then x == y = True

The following operator interactions are expected to hold:

  1. x >= y = y <= x
  2. x < y = x <= y && x /= y
  3. x > y = y < x
  4. x < y = compare x y == LT
  5. x > y = compare x y == GT
  6. x == y = compare x y == EQ
  7. min x y == if x <= y then x else y = True
  8. max 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.

Minimal complete definition

compare | (<=)

Methods

compare :: a -> a -> Ordering Source #

(<) :: a -> a -> Bool infix 4 Source #

(<=) :: a -> a -> Bool infix 4 Source #

(>) :: a -> a -> Bool infix 4 Source #

(>=) :: a -> a -> Bool infix 4 Source #

max :: a -> a -> a Source #

min :: a -> a -> a Source #

Instances

Instances details
Ord ByteArray Source #

Non-lexicographic ordering. This compares the lengths of the byte arrays first and uses a lexicographic ordering if the lengths are equal. Subject to change between major versions.

Since: base-4.17.0.0

Instance details

Defined in Data.Array.Byte

Ord All Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

compare :: All -> All -> Ordering Source #

(<) :: All -> All -> Bool Source #

(<=) :: All -> All -> Bool Source #

(>) :: All -> All -> Bool Source #

(>=) :: All -> All -> Bool Source #

max :: All -> All -> All Source #

min :: All -> All -> All Source #

Ord Any Source #

Since: base-2.1

Instance details

Defined in Data.Semigroup.Internal

Methods

compare :: Any -> Any -> Ordering Source #

(<) :: Any -> Any -> Bool Source #

(<=) :: Any -> Any -> Bool Source #

(>) :: Any -> Any -> Bool Source #

(>=) :: Any -> Any -> Bool Source #

max :: Any -> Any -> Any Source #

min :: Any -> Any -> Any Source #

Ord SomeTypeRep Source # 
Instance details

Defined in Data.Typeable.Internal

Ord Unique Source # 
Instance details

Defined in Data.Unique

Ord Version Source #

Since: base-2.1

Instance details

Defined in Data.Version

Ord CBool Source # 
Instance details

Defined in Foreign.C.Types

Ord CChar Source # 
Instance details

Defined in Foreign.C.Types

Ord CClock Source # 
Instance details

Defined in Foreign.C.Types

Ord CDouble Source # 
Instance details

Defined in Foreign.C.Types

Ord CFloat Source # 
Instance details

Defined in Foreign.C.Types

Ord CInt Source # 
Instance details

Defined in Foreign.C.Types

Ord CIntMax Source # 
Instance details

Defined in Foreign.C.Types

Ord CIntPtr Source # 
Instance details

Defined in Foreign.C.Types

Ord CLLong Source # 
Instance details

Defined in Foreign.C.Types

Ord CLong Source # 
Instance details

Defined in Foreign.C.Types

Ord CPtrdiff Source # 
Instance details

Defined in Foreign.C.Types

Ord CSChar Source # 
Instance details

Defined in Foreign.C.Types

Ord CSUSeconds Source # 
Instance details

Defined in Foreign.C.Types

Ord CShort Source # 
Instance details

Defined in Foreign.C.Types

Ord CSigAtomic Source # 
Instance details

Defined in Foreign.C.Types

Ord CSize Source # 
Instance details

Defined in Foreign.C.Types

Ord CTime Source # 
Instance details

Defined in Foreign.C.Types

Ord CUChar Source # 
Instance details

Defined in Foreign.C.Types

Ord CUInt Source # 
Instance details

Defined in Foreign.C.Types

Ord CUIntMax Source # 
Instance details

Defined in Foreign.C.Types

Ord CUIntPtr Source # 
Instance details

Defined in Foreign.C.Types

Ord CULLong Source # 
Instance details

Defined in Foreign.C.Types

Ord CULong Source # 
Instance details

Defined in Foreign.C.Types

Ord CUSeconds Source # 
Instance details

Defined in Foreign.C.Types

Ord CUShort Source # 
Instance details

Defined in Foreign.C.Types

Ord CWchar Source # 
Instance details

Defined in Foreign.C.Types

Ord IntPtr Source # 
Instance details

Defined in Foreign.Ptr

Ord WordPtr Source # 
Instance details

Defined in Foreign.Ptr

Ord Void Source #

Since: base-4.8.0.0

Instance details

Defined in GHC.Base

Ord ByteOrder Source #

Since: base-4.11.0.0

Instance details

Defined in GHC.ByteOrder

Ord BlockReason Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Ord ThreadId Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.Conc.Sync

Ord ThreadStatus Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.Conc.Sync

Ord TimeoutKey Source # 
Instance details

Defined in GHC.Event.TimeOut

Ord ErrorCall Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.Exception

Ord ArithException Source #

Since: base-3.0

Instance details

Defined in GHC.Exception.Type

Ord Fingerprint Source #

Since: base-4.4.0.0

Instance details

Defined in GHC.Fingerprint.Type

Ord Associativity Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

Ord DecidedStrictness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Ord Fixity Source #

Since: base-4.6.0.0

Instance details

Defined in GHC.Generics

Ord SourceStrictness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Ord SourceUnpackedness Source #

Since: base-4.9.0.0

Instance details

Defined in GHC.Generics

Ord SeekMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Device

Ord ArrayException Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Exception

Ord AsyncException Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Exception

Ord ExitCode Source # 
Instance details

Defined in GHC.IO.Exception

Ord BufferMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.Handle.Types

Ord Newline Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.IO.Handle.Types

Ord NewlineMode Source #

Since: base-4.3.0.0

Instance details

Defined in GHC.IO.Handle.Types

Ord IOMode Source #

Since: base-4.2.0.0

Instance details

Defined in GHC.IO.IOMode

Ord Int16 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Ord Int32 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Ord Int64 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Ord Int8 Source #

Since: base-2.1

Instance details

Defined in GHC.Int

Ord SomeChar Source # 
Instance details

Defined in GHC.TypeLits

Ord SomeSymbol Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.TypeLits

Ord SomeNat Source #

Since: base-4.7.0.0

Instance details

Defined in GHC.TypeNats

Ord GeneralCategory Source #

Since: base-2.1

Instance details

Defined in GHC.Unicode

Ord Word16 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Ord Word32 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Ord Word64 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Ord Word8 Source #

Since: base-2.1

Instance details

Defined in GHC.Word

Ord CBlkCnt Source # 
Instance details

Defined in System.Posix.Types

Ord CBlkSize Source # 
Instance details

Defined in System.Posix.Types

Ord CCc Source # 
Instance details

Defined in System.Posix.Types

Methods

compare :: CCc -> CCc -> Ordering Source #

(<) :: CCc -> CCc -> Bool Source #

(<=) :: CCc -> CCc -> Bool Source #

(>) :: CCc -> CCc -> Bool Source #

(>=) :: CCc -> CCc -> Bool Source #

max :: CCc -> CCc -> CCc Source #

min :: CCc -> CCc -> CCc Source #

Ord CClockId Source # 
Instance details

Defined in System.Posix.Types

Ord CDev Source # 
Instance details

Defined in System.Posix.Types

Ord CFsBlkCnt Source # 
Instance details

Defined in System.Posix.Types

Ord CFsFilCnt Source # 
Instance details

Defined in System.Posix.Types

Ord CGid Source # 
Instance details

Defined in System.Posix.Types

Ord CId Source # 
Instance details

Defined in System.Posix.Types

Methods

compare :: CId -> CId -> Ordering Source #

(<) :: CId -> CId -> Bool Source #

(<=) :: CId -> CId -> Bool Source #

(>) :: CId -> CId -> Bool Source #

(>=) :: CId -> CId -> Bool Source #

max :: CId -> CId -> CId Source #

min :: CId -> CId -> CId Source #

Ord CIno Source # 
Instance details

Defined in System.Posix.Types

Ord CKey Source # 
Instance details

Defined in System.Posix.Types

Ord CMode Source # 
Instance details

Defined in System.Posix.Types

Ord CNfds Source # 
Instance details

Defined in System.Posix.Types

Ord CNlink Source # 
Instance details

Defined in System.Posix.Types

Ord COff Source # 
Instance details

Defined in System.Posix.Types

Ord CPid Source # 
Instance details

Defined in System.Posix.Types

Ord CRLim Source # 
Instance details

Defined in System.Posix.Types

Ord CSocklen Source # 
Instance details

Defined in System.Posix.Types

Ord CSpeed Source # 
Instance details

Defined in System.Posix.Types

Ord CSsize Source # 
Instance details

Defined in System.Posix.Types

Ord CTcflag Source # 
Instance details

Defined in System.Posix.Types

Ord CTimer Source # 
Instance details

Defined in System.Posix.Types

Ord CUid Source # 
Instance details

Defined in System.Posix.Types

Ord Fd Source # 
Instance details

Defined in System.Posix.Types

Methods

compare :: Fd -> Fd -> Ordering Source #

(<) :: Fd -> Fd -> Bool Source #

(<=) :: Fd -> Fd -> Bool Source #

(>) :: Fd -> Fd -> Bool Source #

(>=) :: Fd -> Fd -> Bool Source #

max :: Fd -> Fd -> Fd Source #

min :: Fd -> Fd -> Fd Source #

Ord BigNat 
Instance details

Defined in GHC.Num.BigNat

Ord Ordering 
Instance details

Defined in GHC.Classes

Ord TyCon 
Instance details

Defined in GHC.Classes

Ord Integer 
Instance details

Defined in GHC.Num.Integer

Ord Natural 
Instance details

Defined in GHC.Num.Natural

Ord () 
Instance details

Defined in GHC.Classes

Methods

compare :: () -> () -> Ordering Source #

(<) :: () -> () -> Bool Source #

(<=) :: () -> () -> Bool Source #

(>) :: () -> () -> Bool Source #

(>=) :: () -> () -> Bool Source #

max :: () -> () -> () Source #

min :: () -> () -> () Source #

Ord Bool 
Instance details

Defined in GHC.Classes

Ord Char 
Instance details

Defined in GHC.Classes

Ord Double

Note that due to the presence of NaN, Double's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Double)
False

Also note that, due to the same, Ord's operator interactions are not respected by Double's instance:

>>> (0/0 :: Double) > 1
False
>>> compare (0/0 :: Double) 1
GT
Instance details

Defined in GHC.Classes

Ord Float

Note that due to the presence of NaN, Float's Ord instance does not satisfy reflexivity.

>>> 0/0 <= (0/0 :: Float)
False

Also note that, due to the same, Ord's operator interactions are not respected by Float's instance:

>>> (0/0 :: Float) > 1
False
>>> compare (0/0 :: Float) 1
GT
Instance details

Defined in GHC.Classes

Ord