That's pretty cool. Unfortunately in my early Haskell days the 'not in scope' errors were the only ones I _did_ understand.
Heh :-)
It would be nice to human-friendlify the other types of errors. I'm not judging your work though, this is helpful, and the other types of errors are of course much harder to friendlify.
Yep, this would only be one small step forward in error message quality.
On the topic of things that aren't stupid complaints by me, a typo is the most likely cause for not in scope errors. As Evan points out, I think it would be more helpful to search for matching names in imported modules to see if the name was accidentally not qualified or exported.
Agreed: I've implemented this too. I've also added fuzzy matching to package search: """ $ stage2/ghc-inplace --make ../Test1.hs ../Test1.hs:3:7: Could not find module `Data.Lost': Use -v to see a list of the files searched for. Maybe you meant `Data.List' $ stage2/ghc-inplace --make ../Test2.hs [1 of 1] Compiling Main ( ../Test2.hs, ../Test2.o ) ../Test2.hs:7:14: Not in scope: `isSpace' Maybe you meant `Char.isSpace' """
I don't know about this fuzzy matching business, since when I go to the line of the error message, I'm going to see my typo and what I meant. I don't think I'd ever use the suggestions...
I can think of a few times it would have helped me out, with identifiers that may or may not be pluralized or have suprising capitalisation. I don't know though, I guess you'd have to work with the feature turned on for a while to work out if it really was useful. I think this feature has shaped up pretty nicely after the helpful suggestions I recieved. I don't know if I'll be able to get the patch into GHC proper, though.. Max