what about pattern matching?
Yes, pattern matching is the issue that occurs to me too. While string literals :: ByteString would be nice (and other magic encoded in string literals, I guess), what is the story for pattern matching on strings based on non-inductive types like arrays?
Pattern matching would work like pattern matching with numeric literals does. You'll have to use equality comparison. To pattern match the string type would have to be in Eq as well.
Mh, that's a showcase for Views. Something like view IsString a => String of a where ... That is, one has an already existing type that serves as a view for another one. Perhaps, Views should be more like class declarations with asssociated constructors class IsString a where [] :: a (:) :: Char -> a -> a Very similar to the new (G)ADT syntax and some kind of polymorphic variants with "virtual" constructors, isn't it? Anyway, the pattern guard approach would be to *not* allow string literals in pattern matches: patty bs | "pattern string" == bs = flip id id . flip id I think it's very unfair not to have general Views when now both polymorphic integers and string literals are to be allowed in pattern matching. Regards, apfelmus