On Sun, Apr 1, 2012 at 1:58 PM, aditya bhargava
After asking this question: http://stackoverflow.com/questions/9963050/standard-way-of-joining-two-data-...
I found out that the new infix operator for `mappend` is (<>). I'm wondering why ghc 7.4 didn't generalize (++) to work on monoids instead.
Such decisions should really be made by the Haskell Prime committee (vs GHC HQ). In Haskell there is a continuing tension between making things polymorphic and to keep the prelude functions monomorphic so they generate simple error messages (among other arguments). At the point, the additional argument of any new definition of "Haskell" remaining backwards compatible also holds weight and this slows the rate-of-change. This is not a new issue, there are a number of functions that could be defined more generally (common example: map/fmap). The problem making such changes is a matter of consensus and will to see things though. Cheers, Thomas