2006/2/6, David Roundy
Actually couldn't they all be made polymorphic?
getDirectoryContents :: FilePath p => IO p
class FilePath p where fromADT :: ADT -> p toADT :: p -> ADT
Would you mean that we should have two instances: instance FilePath String where .... instance FilePath ADT where .... It will work but I think that it is unnecessary complication. I prefer to use type classes only when they are really necessary i.e. when I have more than 2-3 instances or when I expect to have a lot of generic code that should work on both types. I think that if we should switch from plain String to ADT then this should be made for a new i/o library (the Handle(s) replacement) which will change the thing a lot in any way. For the current library I think that the plain String is more reasonable. If the general consensus is that ADT is the way to go then I think some effort on a new efficient IO library be forced. It should have: - FilePath ADT - Packed string - Fast I/O with unicode support I know some pieces already exists but they need integration and polishing. Cheers, Krasimir