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Within LTS Haskell 24.45 (ghc-9.10.3)
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construct Construct.Classes Converts a parser accepting one input stream type to another just like mapParserInput, except the argument functions can return Nothing to indicate they need more input.
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construct Construct.Classes Converts a parser accepting one input stream type to another. The functions forth and back must be inverses of each other and they must distribute through <>:
f (s1 <> s2) == f s1 <> f s2
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])control-monad-free Control.Monad.Free 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.
mapFree :: (Functor f, Functor g) => (f (Free g a) -> g (Free g a)) -> Free f a -> Free g acontrol-monad-free Control.Monad.Free No documentation available.
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control-monad-free Control.Monad.Free No documentation available.
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control-monad-free Control.Monad.Free No documentation available.
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control-monad-free Control.Monad.Free No documentation available.
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control-monad-free Control.Monad.Free No documentation available.
mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)control-monad-free Control.Monad.Free 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 ()control-monad-free Control.Monad.Free 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.