Re: [Haskell-cafe] type checking that I can't figure out ....

G'day Vasili. This should do it: remLookupFwd :: (ReVars m t) => SimplRe t -> ReM m t (ReInfo t) remLookupFwd re = do fwd <- gets resFwdMap let { Just reinfo = fromJust (M.lookup re fwd) } return reinfo The FiniteMap lookup operation took its arguments in the opposite order. That's really the only problem here AFAICT. Wow, this brings back memories. I wrote this module about ten years ago, and I'm shocked that it's still getting use. I'd appreciate a copy when you're done updating it for the modern era. Cheers, Andrew Bromage