Safe Haskell | Safe-Inferred |
---|
Common utilities used throughout the project.
- listDeleteIndex :: Int -> [a] -> [a]
- listReplace :: Eq a => a -> a -> [a] -> [a]
- listUpdate :: Show a => (a -> a) -> Int -> [a] -> [a]
- fromLeft :: Either a b -> a
- fromRight :: Either a b -> b
- onLeft :: (a -> c) -> Either a b -> Either c b
- onRight :: (b -> c) -> Either a b -> Either a c
- andEithers :: [Either a b] -> Either [a] [b]
- for :: [a] -> (a -> b) -> [b]
- mapTuple :: (a -> b) -> (a, a) -> (b, b)
- whenMaybe :: Monad m => Maybe a -> (a -> m ()) -> m ()
- cond :: a -> [(Bool, a)] -> a
- if' :: a -> a -> Bool -> a
- andM :: Monad m => [m Bool] -> m Bool
- forIndexM_ :: Monad m => [a] -> (Int -> a -> m ()) -> m ()
- whileM :: Monad m => m Bool -> m () -> m ()
- whileM' :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()
- doWhileM :: Monad m => a -> (a -> m (Either b a)) -> m b
- newtype Seq m = Seq (m ())
Documentation
listDeleteIndex :: Int -> [a] -> [a]Source
Drops the element at an index from a list. If the index is out of bounds then the list is returned unmodified.
listReplace :: Eq a => a -> a -> [a] -> [a]Source
listReplace old new list
replaces all occurrences of old
with new
in
list
.
listUpdate :: Show a => (a -> a) -> Int -> [a] -> [a]Source
Modifies the element at a specific index in a list.
onLeft :: (a -> c) -> Either a b -> Either c bSource
Transforms the left value of an Either
, leaving a right value alone.
onRight :: (b -> c) -> Either a b -> Either a cSource
Transforms the right value of an Either
, leaving a left value alone.
This is just fmap
, but looks nicer when used beside onLeft
.
andEithers :: [Either a b] -> Either [a] [b]Source
If any item is a Left
, then the list of Left
s is returned, otherwise
the list of Right
s is returned.
whenMaybe :: Monad m => Maybe a -> (a -> m ()) -> m ()Source
Executes the monadic function if a Maybe
contains a value.
cond :: a -> [(Bool, a)] -> aSource
Finds the first tuple whose first element is true, and returns its second
element. If all of the first values are false, then the first argument to
cond
is returned instead.
andM :: Monad m => [m Bool] -> m BoolSource
and
in a monad. Executes the actions in the list in order. If any
action returns false then the remaining actions are skipped and the result is
false. Otherwise all actions returned true, and the result is true. An
empty list returns true.
forIndexM_ :: Monad m => [a] -> (Int -> a -> m ()) -> m ()Source
forM_
that also passes in the index of each element.
whileM :: Monad m => m Bool -> m () -> m ()Source
whileM test body
repeatedly evaluates test
until it returns false.
Every time test
returns true, body
is executed once.
whileM' :: Monad m => m (Maybe a) -> (a -> m ()) -> m ()Source
whileM' test body
repeatedly evaluates test
until it returns Nothing
.
Every time it returns a Just
, that value is passed to body
and the result
is executed.