Hoogle Search

Within LTS Haskell 24.38 (ghc-9.10.3)

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

  1. mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)

    ghc-internal GHC.Internal.Data.Traversable

    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"])

  2. mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)

    ghc-internal GHC.Internal.Data.Traversable

    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

    mapM is literally a traverse with a type signature restricted to Monad. Its implementation may be more efficient due to additional power of Monad.

  3. mapExceptionContext :: (ExceptionContext -> ExceptionContext) -> SomeException -> SomeException

    ghc-internal GHC.Internal.Exception.Type

    No documentation available.

  4. mapAccumL :: (acc -> x -> (acc, y)) -> acc -> Infinite x -> Infinite y

    infinite-list Data.List.Infinite

    Fold an infinite list from the left and return a list of successive reductions, keeping accumulator in a state: 

    mapAccumL f acc0 (x1 :< x2 :< ...) =
let (acc1, y1) = f acc0 x1 in
let (acc2, y2) = f acc1 x2 in
...
y1 :< y2 :< ...
    If you are looking how to traverse with a state, look no further.

  5. mapAccumL' :: (acc -> x -> (acc, y)) -> acc -> Infinite x -> Infinite y

    infinite-list Data.List.Infinite

    Same as mapAccumL, but strict in accumulator.

  6. mapEither :: (a -> Either b c) -> Infinite a -> (Infinite b, Infinite c)

    infinite-list Data.List.Infinite

    Apply a function to every element of an infinite list and separate Left and Right results. This function isn't productive (e. g., head . fst . mapEither f won't terminate), if no elements of the input list result in Left or Right.

  7. mapMaybe :: (a -> Maybe b) -> Infinite a -> Infinite b

    infinite-list Data.List.Infinite

    Apply a function to every element of an infinite list and collect Just results. This function isn't productive (e. g., head . mapMaybe f won't terminate), if no elements of the input list result in Just.

  8. mapConcurrently :: (Traversable t, MonadBaseControl IO m) => (a -> m b) -> t a -> m (t b)

    lifted-async Control.Concurrent.Async.Lifted

    Generalized version of mapConcurrently.

  9. mapConcurrently_ :: (Foldable t, MonadBaseControl IO m) => (a -> m b) -> t a -> m ()

    lifted-async Control.Concurrent.Async.Lifted

    Generalized version of mapConcurrently_.

  10. mapConcurrently :: (Traversable t, MonadBaseControl IO m, Forall (Pure m)) => (a -> m b) -> t a -> m (t b)

    lifted-async Control.Concurrent.Async.Lifted.Safe

    Generalized version of mapConcurrently.

Page 159 of many | Previous | Next