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  1. decide :: Decide f => (a -> Either b c) -> f b -> f c -> f a

    semigroupoids Data.Functor.Contravariant.Decide

    Takes the "decision" method and the two potential consumers, and returns the wrapped/combined consumer.

  2. decided :: Decide f => f b -> f c -> f (Either b c)

    semigroupoids Data.Functor.Contravariant.Decide

    For decided x y, the resulting f (Either b c) will direct Lefts to be consumed by x, and Rights to be consumed by y.

  3. gdecide :: (Generic1 f, Decide (Rep1 f)) => (a -> Either b c) -> f b -> f c -> f a

    semigroupoids Data.Functor.Contravariant.Decide

    Generic decide. Caveats:

    1. Will not compile if f is a sum type.
    2. Will not compile if f contains fields that do not mention its type variable.
    3. -XDeriveGeneric is not smart enough to make instances where the type variable appears in negative position.

  4. gdecided :: (Generic1 f, Decide (Rep1 f)) => f b -> f c -> f (Either b c)

    semigroupoids Data.Functor.Contravariant.Decide

    Generic decided. Caveats are the same as for gdecide.

  5. module Data.Groupoid

    No documentation available.

  6. class Semigroupoid k1 => Groupoid (k1 :: k -> k -> Type)

    semigroupoids Data.Groupoid

    semigroupoid with inverses. This technically should be a category with inverses, except we need to use Ob to define the valid objects for the category

  7. module Data.Semigroupoid

    A semigroupoid satisfies all of the requirements to be a Category except for the existence of identity arrows.

  8. class Semigroupoid (c :: k -> k -> Type)

    semigroupoids Data.Semigroupoid

    Category sans id

  9. semiid :: Ob k1 a => k1 a a

    semigroupoids Data.Semigroupoid.Ob

    No documentation available.

  10. void :: Functor f => f a -> f ()

    base-compat Data.Functor.Compat

    void value discards or ignores the result of evaluation, such as the return value of an IO action.

    Examples

    Replace the contents of a Maybe Int with unit: 
    >>> void Nothing
Nothing

    >>> void (Just 3)
Just ()
    Replace the contents of an Either Int Int with unit, resulting in an Either Int (): 
    >>> void (Left 8675309)
Left 8675309

    >>> void (Right 8675309)
Right ()
    Replace every element of a list with unit: 
    >>> void [1,2,3]
[(),(),()]
    Replace the second element of a pair with unit: 
    >>> void (1,2)
(1,())
    Discard the result of an IO action: 
    >>> mapM print [1,2]
1
2
[(),()]

    >>> void $ mapM print [1,2]
1
2

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