semigroupoids-3.0.3: Haskell 98 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

Constructors

Dual 

Fields

getDual :: k b a
 

Instances