semigroupoids-4.2: Semigroupoids: Category sans id

Portabilityportable
Stabilityprovisional
MaintainerEdward Kmett <ekmett@gmail.com>
Safe HaskellSafe-Inferred

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