(a -> b) -> (a, a) -> (b, b) -fgl

(^<<) :: Arrow a => (c -> d) -> a b c -> a b d
base Control.Arrow
Postcomposition with a pure function (right-to-left variant).
firstf :: (a -> c) -> Maybe (a, b) -> Maybe (c, b)
text Data.Text.Internal
Apply a function to the first element of an optional pair.
(>>^) :: Arrow a => a b c -> (c -> d) -> a b d
base Control.Arrow
Postcomposition with a pure function.
ixmap :: (IArray a e, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> a i e
array Data.Array.IArray
Returns a new array derived from the original array by applying a function to each of the indices.
amap :: (IArray a e', IArray a e, Ix i) => (e' -> e) -> a i e' -> a i e
array Data.Array.IArray
Returns a new array derived from the original array by applying a function to each of the elements.
(^>>) :: Arrow a => (b -> c) -> a c d -> a b d
base Control.Arrow
Precomposition with a pure function.
(<<^) :: Arrow a => a c d -> (b -> c) -> a b d
base Control.Arrow
Precomposition with a pure function (right-to-left variant).
mapArray :: (MArray a e' m, MArray a e m, Ix i) => (e' -> e) -> a i e' -> m (a i e)
array Data.Array.MArray, array Data.Array.MArray.Safe
Constructs a new array derived from the original array by applying a function to each of the elements.
mapIndices :: (MArray a e m, Ix i, Ix j) => (i, i) -> (i -> j) -> a j e -> m (a i e)
array Data.Array.MArray, array Data.Array.MArray.Safe
Constructs a new array derived from the original array by applying a function to each of the indices.