ekmett/semigroups — pull request #8 by ppetr (2012-12-15 17:49:08+00:00)
Title: Suggestion: Type classes for semigroup/monoid actions.

For my project I found it useful to represent semigroup/monoid actions on a type as a (multi-param) type class. It's basically just a class definition, nothing more, but I felt it could well fit into _semigroups_.