semigroupoids-5.3.7: Semigroupoids: Category sans id
Copyright (C) 2007-2015 Edward Kmett
License BSD-style (see the file LICENSE)
Maintainer Edward Kmett <ekmett@gmail.com>
Stability provisional
Portability portable
Safe Haskell Safe
Language Haskell2010

Data.Semigroupoid.Dual

Description

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

Documentation

newtype Dual k a b Source #

Constructors

Dual

Fields

Instances

Instances details
Category k2 => Category ( Dual k2 :: k1 -> k1 -> Type ) Source #
Instance details

Defined in Data.Semigroupoid.Dual

Methods

id :: forall (a :: k). Dual k2 a a Source #

(.) :: forall (b :: k) (c :: k) (a :: k). Dual k2 b c -> Dual k2 a b -> Dual k2 a c Source #

Semigroupoid k2 => Semigroupoid ( Dual k2 :: k1 -> k1 -> Type ) Source #
Instance details

Defined in Data.Semigroupoid.Dual

Methods

o :: forall (j :: k) (k :: k) (i :: k). Dual k2 j k -> Dual k2 i j -> Dual k2 i k Source #

Groupoid k2 => Groupoid ( Dual k2 :: k1 -> k1 -> Type ) Source #
Instance details

Defined in Data.Groupoid

Methods

inv :: forall (a :: k) (b :: k). Dual k2 a b -> Dual k2 b a Source #