name:             groupoid
version:          0.1.0
license:          BSD3
license-file:     LICENSE
copyright:        Stephen Tetley <stephen.tetley@gmail.com>
maintainer:       Stephen Tetley <stephen.tetley@gmail.com>
homepage:         http://code.google.com/p/copperbox/
category:         Data
synopsis:         A Groupoid class
description:
  .
  A groupoid is structure consisting of a set of elements (here 
  a Haskell type) and a binary operator (in present case the 
  function 'gappend').
  .
  It is comparable to the Monoid typeclass, but there is no 
  obligation that the set supports a neutral element (mempty in
  Data.Monoid). 
  .
  In geometry, bounding boxes (represented as two points - 
  bottom-left corner and top-right corner) give an example where 
  a groupoid may be more satisfying than a monoid. The union 
  operation on bounding boxes is essential to track the extent 
  of shapes after their superimposition. To fit bounding box 
  union into the Monoid typeclass one can do a clever trick 
  representing mempty with the bottom-left corner at positive 
  infinity and the top-right corner at negative infinity, the 
  standard implementation of union which uses min and max will 
  still proceed to identify the extreme corners correctly. This 
  is nice enough if the bounding box coordinates are represented 
  by Doubles, but a problem if they are Ints (say representing 
  grid coordinates) - one might decide it is better simply to 
  consider concrete bounding boxes and not their empty/infinite 
  cousins.

build-type:         Simple
stability:          highly unstable
cabal-version:      >= 1.2

extra-source-files:

library
  hs-source-dirs:     src
  build-depends:      base<5

  
  exposed-modules:
    Data.Groupoid

  other-modules:
    
  extensions:
    

  ghc-options:
  
  includes: