Hoogle Search

Within LTS Haskell 24.3 (ghc-9.10.2)

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

Exact lookup

1. mapMaybeWithKey :: (k -> a -> Maybe b) -> Map k a -> Map k b

   containers	Data.Map.Strict.Internal

   Map keys/values and collect the Just results.

   let f k _ = if k < 5 then Just ("key : " ++ (show k)) else Nothing
   mapMaybeWithKey f (fromList [(5,"a"), (3,"b")]) == singleton 3 "key : 3"
   

2. mapMaybeT :: (m (Maybe a) -> n (Maybe b)) -> MaybeT m a -> MaybeT n b

   transformers	Control.Monad.Trans.Maybe

   Transform the computation inside a MaybeT.

   • runMaybeT (mapMaybeT f m) = f (runMaybeT
     m)

3. mapMaybeWithKey :: (Key -> v -> Maybe u) -> KeyMap v -> KeyMap u

   aeson	Data.Aeson.KeyMap

   Map values and collect the Just results.

4. mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2

   unordered-containers	Data.HashMap.Internal

   Transform this map by applying a function to every value and retaining only some of them.

5. mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2

   unordered-containers	Data.HashMap.Internal.Strict

   Transform this map by applying a function to every value and retaining only some of them.

6. mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2

   unordered-containers	Data.HashMap.Lazy

   Transform this map by applying a function to every value and retaining only some of them.

7. mapMaybeWithKey :: (k -> v1 -> Maybe v2) -> HashMap k v1 -> HashMap k v2

   unordered-containers	Data.HashMap.Strict

   Transform this map by applying a function to every value and retaining only some of them.

8. mapMaybePrimArray :: (Prim a, Prim b) => (a -> Maybe b) -> PrimArray a -> PrimArray b

   primitive	Data.Primitive.PrimArray

   Map over a primitive array, optionally discarding some elements. This has the same behavior as Data.Maybe.mapMaybe.

9. mapMaybePrimArrayA :: (Applicative f, Prim a, Prim b) => (a -> f (Maybe b)) -> PrimArray a -> f (PrimArray b)

   primitive	Data.Primitive.PrimArray

   Map over the primitive array, keeping the elements for which the applicative predicate provides a Just.

10. mapMaybePrimArrayP :: (PrimMonad m, Prim a, Prim b) => (a -> m (Maybe b)) -> PrimArray a -> m (PrimArray b)

    primitive	Data.Primitive.PrimArray

    Map over the primitive array, keeping the elements for which the monadic predicate provides a Just.

Page 15 of many | Previous | Next