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HsYAML Data.YAML No documentation available.
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ListLike Data.ListLike A map in monad space. Same as sequence . map See also rigidMapM
mapM_ :: (Monad m, FoldableLL full item) => (item -> m b) -> full -> m ()ListLike Data.ListLike A map in monad space, discarding results.
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ListLike Data.ListLike.Base A map in monad space. Same as sequence . map See also rigidMapM
mapM_ :: (Monad m, FoldableLL full item) => (item -> m b) -> full -> m ()ListLike Data.ListLike.FoldableLL A map in monad space, discarding results.
mapAccumL :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)basic-prelude BasicPrelude 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"])mapAccumR :: Traversable t => (s -> a -> (s, b)) -> s -> t a -> (s, t b)basic-prelude BasicPrelude 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"])mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])basic-prelude BasicPrelude 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.
mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)basic-prelude BasicPrelude 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.mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()basic-prelude BasicPrelude Map each element of a structure to a monadic action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see mapM. mapM_ is just like traverse_, but specialised to monadic actions.