On Fri, 7 Jan 2005, Simon Peyton-Jones wrote: > | * As far as I can determine, there is no way to check pattern matches > for > | exhaustiveness. Coming from OCaml, this feels like losing a > significant > | safety net! How do people program so as not to be getting dynamic > match > | failures all the time? > > GHC has -fwarn-incomplete-patterns and -fwarn-overlapped-patterns. But > the code implementing these checks is old and crufty, and the warnings > are sometimes a bit wrong -- at least when guards and numeric literals > are involved. I think they are accurate when you are just using > "ordinary" pattern matching. > > Cleaning up this bit of GHC is a long-standing to-do item, if anyone > feels motivated to undertake it. It's a well-defined task, with plenty > of well-written papers explaining how to do it -- but it's tricker than > it seems at first!
What about dropping Guards? :-) Are they necessary? Do they lead to more readable source code? Do they lead to more efficient code? I could perfectly live without them up to now. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
