 categoryextras0.53.6: Various modules and constructs inspired by category theory  Contents  Index 

Control.Category.Object  Portability  nonportable (either classassociated types or MPTCs with fundeps)  Stability  experimental  Maintainer  Edward Kmett <ekmett@gmail.com> 



Description 
This module declares the HasTerminalObject and HasInitialObject classes.
These are defined in terms of classassociated types rather than functional dependencies
because most of the time when you are manipulating a category you don't care about them;
this gets them out of the signature of most functions that use the category.
Both of these are special cases of the idea of a (co)limit.


Synopsis 



Documentation 

class Category k => HasTerminalObject k t  k > t where 
The Category k has a terminal object Terminal k such that for all objects a in k,
there exists a unique morphism from a to Terminal k.
  Methods  


class Category k => HasInitialObject k i  k > i where 
The Category k has an initial (coterminal) object Initial k such that for all objects
a in k, there exists a unique morphism from Initial k to a.
  Methods  


Produced by Haddock version 2.1.0 