semigroupoids-4.3: Semigroupoids: Category sans id

Copyright(C) 2007-2011 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
Portabilityportable
Safe HaskellSafe-Inferred
LanguageHaskell98

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

getDual :: k b a
 

Instances

Category * k => Category * (Dual k) 
Semifunctor f c d => Semifunctor f (Dual c) (Dual d) 
Semigroupoid k => Semigroupoid (Dual k) 
Groupoid k => Groupoid (Dual k)