category-extras-0.53.0: Various modules and constructs inspired by category theory

Portabilitynon-portable (rank-2 polymorphism)
Stabilityexperimental
MaintainerEdward Kmett <ekmett@gmail.com>

Control.Morphism.Span

Description

Spans and Cospans http://en.wikipedia.org/wiki/Span_(category_theory)

Documentation

newtype Span (~>) x y z Source

Constructors

Span 

Fields

runSpan :: (y ~> x, y ~> z)
 

newtype Cospan (~>) x y z Source

Constructors

Cospan 

Fields

runCospan :: (x ~> y, z ~> y)