Control.Categorical.Object

This module declares the HasTerminalObject and HasInitialObject classes.

These are both special cases of the idea of a (co)limit.

Documentation

class Category ~> => HasTerminalObject (~>) where

The Category (~>) has a terminal object Terminal (~>) such that for all objects a in (~>), there exists a unique morphism from a to Terminal (~>).

Associated Types

type Terminal (~>) :: *

Methods

terminate :: a ~> Terminal ~>

class Category ~> => HasInitialObject (~>) where

The Category (~>) has an initial (coterminal) object Initial (~>) such that for all objects a in (~>), there exists a unique morphism from Initial (~>) to a.

Associated Types

type Initial (~>) :: *

Methods

initiate :: Initial ~> ~> a