semigroupoids-5.3.1: Semigroupoids: Category sans id

Copyright(C) 2007-2015 Edward Kmett
LicenseBSD-style (see the file LICENSE)
MaintainerEdward Kmett <ekmett@gmail.com>
Stabilityprovisional
Portabilityportable
Safe HaskellNone
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

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

Defined in Data.Semigroupoid.Dual

Methods

id :: Dual k2 a a #

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

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

Defined in Data.Semigroupoid.Dual

Methods

o :: Dual k2 j k -> Dual k2 i j -> Dual k2 i k Source #

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

Defined in Data.Groupoid

Methods

inv :: Dual k2 a b -> Dual k2 b a Source #