semigroupoids-5.0.0.1: Semigroupoids: Category sans id

Copyright(C) 2007-2015 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 k1 => Category k (Dual k k k) 
Semigroupoid k k1 => Semigroupoid k (Dual k k k) 
Groupoid k k1 => Groupoid k (Dual k k k)