Hi > Tools like Neil Mitchell's Catch can do more sophisticated checking, as long > as your program can be compiled by YHC. Sometimes fromJust can be quite > useful, though, especially in tandem with isJust. For example, > >> prop_foobar :: SomeType -> Property >> prop_foobar x >> = isJust (someTypeToMaybe x) ==> fromJust x == expectedResult
I was thinking of jumping in on this thread, to advertise Catch, but unfortunately "can be compiled with Yhc" makes it a fairly niche tool :-( However, the fundamental bit of Catch works on an a normal Core language, and I do want to hook it up to GHC's Core language at some point. It could certainly deal with prop_foobar, and things that are far more complex. To get an idea of what Catch can do, I recommend reading the draft paper and skipping to section 5.4 where I verify the entire HsColour program with one small refactoring and no annotations. I even found 3 real crashing bugs in HsColour, that were fixed because Catch pointed them out. Incomplete patterns + a checker (Catch) are just a faster and more efficient way of writing complete patterns without dead code :-) Catch: http://www-users.cs.york.ac.uk/~ndm/catch/ Thanks Neil _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
