Hoogle Search

Within LTS Haskell 24.32 (ghc-9.10.3)

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

Exact lookup

1. toMaybe :: Bool -> a -> Maybe a

   utility-ht	Data.Maybe.HT

   Returns Just if the precondition is fulfilled. prop> b x -> (guard b >> x) == (toMaybe b =<< (x::Maybe Char))

2. mapMaybe :: forall (m :: Type -> Type) a b . Functor m => (a -> Maybe b) -> SourceT m a -> SourceT m b

   servant	Servant.Types.SourceT

   Filter values.

   >>> toList $ mapMaybe (\x -> if odd x then Just x else Nothing) (source [0..10]) :: [Int]
   [1,3,5,7,9]
   

   >>> mapMaybe (\x -> if odd x then Just x else Nothing) (source [0..2]) :: SourceT Identity Int
   fromStepT (Effect (Identity (Skip (Yield 1 (Skip Stop)))))
   

   Illustrates why we need Skip.

3. mapMaybeStep :: forall (m :: Type -> Type) a b . Functor m => (a -> Maybe b) -> StepT m a -> StepT m b

   servant	Servant.Types.SourceT

   No documentation available.

4. parseMaybe :: (a -> Parser b) -> a -> Maybe b

   yaml	Data.Yaml

   Run a Parser with a Maybe result type.

5. genMaybe :: Gen a -> Gen (Maybe a)

   genvalidity	Data.GenValidity.Utils

   No documentation available.

6. shrinkMaybe :: (a -> [a]) -> Maybe a -> [Maybe a]

   genvalidity	Data.GenValidity.Utils

   Lift a shrinker function into a maybe

7. isClassOpId_maybe :: Id -> Maybe Class

   ghc	GHC

   No documentation available.

8. synTyConDefn_maybe :: TyCon -> Maybe ([TyVar], Type)

   ghc	GHC

   Extract the TyVars bound by a vanilla type synonym and the corresponding (unsubstituted) right hand side.

9. synTyConRhs_maybe :: TyCon -> Maybe Type

   ghc	GHC

   Extract the information pertaining to the right hand side of a type synonym (type) declaration.

10. tyConClass_maybe :: TyCon -> Maybe Class

    ghc	GHC

    If this TyCon is that for a class instance, return the class it is for. Otherwise returns Nothing

Page 115 of many | Previous | Next