Hoogle Search

Within LTS Haskell 24.39 (ghc-9.10.3)

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

Exact lookup

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

   calligraphy	Calligraphy.Prelude

   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.

2. mappend :: Monoid a => a -> a -> a

   calligraphy	Calligraphy.Prelude

   An associative operation NOTE: This method is redundant and has the default implementation mappend = (<>) since base-4.11.0.0. Should it be implemented manually, since mappend is a synonym for (<>), it is expected that the two functions are defined the same way. In a future GHC release mappend will be removed from Monoid.

3. mapError :: (MonadError e m, MonadError e' n) => (m (Either e a) -> n (Either e' b)) -> m a -> n b

   can-i-haz	Control.Monad.Except.CoHas

   MonadError analogue of the mapExceptT function. The computation is unwrapped, a function is applied to the Either, and the result is lifted into the second MonadError instance.

4. mapExcept :: (Either e a -> Either e' b) -> Except e a -> Except e' b

   can-i-haz	Control.Monad.Except.CoHas

   Map the unwrapped computation using the given function.

   • runExcept (mapExcept f m) = f (runExcept
     m)

5. mapExceptT :: (m (Either e a) -> n (Either e' b)) -> ExceptT e m a -> ExceptT e' n b

   can-i-haz	Control.Monad.Except.CoHas

   Map the unwrapped computation using the given function.

   • runExceptT (mapExceptT f m) = f
     (runExceptT m)

6. mapReader :: (a -> b) -> Reader r a -> Reader r b

   can-i-haz	Control.Monad.Reader.Has

   Transform the value returned by a Reader.

   • runReader (mapReader f m) = f .
     runReader m

7. mapReaderT :: (m a -> n b) -> ReaderT r m a -> ReaderT r n b

   can-i-haz	Control.Monad.Reader.Has

   Transform the computation inside a ReaderT.

   • runReaderT (mapReaderT f m) = f .
     runReaderT m

8. mapMaybeVarEnv :: (a -> Maybe b) -> VarEnv a -> VarEnv b

   clash-lib	Clash.Core.VarEnv

   Apply a function to every element in the environment; values for which the function returns Nothing are removed from the environment

9. mapVarEnv :: (a -> b) -> VarEnv a -> VarEnv b

   clash-lib	Clash.Core.VarEnv

   Apply a function to every element in the environment

10. mapMaybe :: (a -> Maybe b) -> UniqMap a -> UniqMap b

    clash-lib	Clash.Data.UniqMap

    Apply a function to all elements in the map, keeping those where the result is not Nothing.

Page 322 of many | Previous | Next