2009/1/19 Luke Palmer <lrpal...@gmail.com>: > On Mon, Jan 19, 2009 at 3:58 AM, Patai Gergely <patai_gerg...@fastmail.fm> > wrote: >> >> However, there are other type classes that are too general to assign >> such concrete uses to. For instance, if a data structure can have more >> than one meaningful (and useful) Functor or Monoid instance, > > As a side curiosity, I would love to see an example of any data structure > which has more than one Functor instance. Especially those which have more > than one useful functor instance. > Luke
The recent, and great, blog post about moniods [1] discusses the fact that (Num a) could be one of several different monoids and how that was handled. [1] http://sigfpe.blogspot.com/2009/01/haskell-monoids-and-their-uses.html _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
