Hoogle Search

Within LTS Haskell 24.6 (ghc-9.10.2)

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

Exact lookup

1. mapM_ :: forall m a b (n :: Nat) . Monad m => (a -> m b) -> ListN n a -> m ()

   basement	Basement.Sized.List

   Map each element of a List to a monadic action, evaluate these actions sequentially and ignore the results

2. mapMaybe :: (a -> Maybe b) -> EnumMap k a -> EnumMap k b

   enummapset	Data.EnumMap.Lazy

   No documentation available.

3. mapMaybeWithKey :: Enum k => (k -> a -> Maybe b) -> EnumMap k a -> EnumMap k b

   enummapset	Data.EnumMap.Lazy

   No documentation available.

4. mapMaybe :: (a -> Maybe b) -> EnumMap k a -> EnumMap k b

   enummapset	Data.EnumMap.Strict

   No documentation available.

5. mapMaybeWithKey :: Enum k => (k -> a -> Maybe b) -> EnumMap k a -> EnumMap k b

   enummapset	Data.EnumMap.Strict

   No documentation available.

6. mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()

   ghc-internal	GHC.Internal.Control.Monad

   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.

7. mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()

   ghc-internal	GHC.Internal.Data.Foldable

   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.

8. mapMaybe :: (a -> Maybe b) -> [a] -> [b]

   ghc-internal	GHC.Internal.Data.Maybe

   The mapMaybe function is a version of map which can throw out elements. In particular, the functional argument returns something of type Maybe b. If this is Nothing, no element is added on to the result list. If it is Just b, then b is included in the result list.

   Examples

   Using mapMaybe f x is a shortcut for catMaybes $ map f x in most cases:

   >>> import GHC.Internal.Text.Read ( readMaybe )
   
   >>> let readMaybeInt = readMaybe :: String -> Maybe Int
   
   >>> mapMaybe readMaybeInt ["1", "Foo", "3"]
   [1,3]
   
   >>> catMaybes $ map readMaybeInt ["1", "Foo", "3"]
   [1,3]
   

   If we map the Just constructor, the entire list should be returned:

   >>> mapMaybe Just [1,2,3]
   [1,2,3]
   

9. mapM_ :: (Source r a, Index ix, Monad m) => (a -> m b) -> Array r ix a -> m ()

   massiv	Data.Massiv.Array

   Map a monadic function over an array sequentially, while discarding the result.

   Examples

   >>> import Data.Massiv.Array as A
   
   >>> rangeStepM Par (Ix1 10) 12 60 >>= A.mapM_ print
   10
   22
   34
   46
   58
   

10. mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()

    protolude	Protolude

    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.

Page 31 of many | Previous | Next