On Wed, Aug 18, 2010 at 02:00:39PM +0200, Johan Tibell wrote: > > The current API doesn't offer any efficient way to do something simple as > e.g. summing the values in a map. I suggest we add a foldlWithKey' function: > > http://hackage.haskell.org/trac/ghc/ticket/4261 Shouldn't (go z l) be forced too? Thanks Ian