Annotations.Except

The Except datatype captures monoidal exceptions in applicative computations.

Documentation

data Except e a

Except is like Either but is meant to be used only in applicative computations. When two exceptions are sequenced, their sum (using mappend) is computed.

Constructors

Failed e

OK a

Instances

Functor (Except e)

Methods

fmap :: (a -> b) -> Except e a -> Except e b

(<$) :: a -> Except e b -> Except e a

Monoid e => Applicative (Except e)

Methods

pure :: a -> Except e a

(<*>) :: Except e (a -> b) -> Except e a -> Except e b

(*>) :: Except e a -> Except e b -> Except e b

(<*) :: Except e a -> Except e b -> Except e a

(Eq a, Eq e) => Eq (Except e a)

Methods

(==) :: Except e a -> Except e a -> Bool

(/=) :: Except e a -> Except e a -> Bool

(Show a, Show e) => Show (Except e a)

Methods

showsPrec :: Int -> Except e a -> ShowS

show :: Except e a -> String

showList :: [Except e a] -> ShowS