On Tue, May 8, 2012 at 2:36 PM, MigMit <miguelim...@yandex.ru> wrote: > Hi café, a quick question. > > Is there a somewhat standard class like this: > > class Something c where > unit :: c () () > pair :: c x y -> c u v -> c (x, u) (y, v) > > ? > > I'm using it heavily in my current project, but I don't want to repeat > somebody else's work, and it seems general enough to be defined somewhere; > but my quick search on Hackage didn't reveal anything. > > I know about arrows; this, however, is something more general, and it's > instances aren't always arrows.
Are you aware of generalized arrows [1]? It's still a lot more than your Something, though. [1] http://www.cs.berkeley.edu/~megacz/garrows/ -- Felipe. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe