Types cannot always be derived automatically, especially when coming to Haskell extensions. Sometimes you also want to restrict the type. E.g. for asTypeOf _ y = y you explicitly want the type asTypeOf :: a -> a -> a not the automatically derived one: asTypeOf :: b -> a -> a
Yes, sometimes it is neccerary to give an explicit type. But in so many cases, type inference works fine no? What I usually do, is use the GHCi t: command, copy/paste that in my code, and then make the type signature more specific if it has to be. It's often funny to see how generic the code really is :) I wonder what a typical LISP/Scheme programmer thinks of type signatures...
It's a problem in Haskell that there are no unique parameter names, due to pattern matching.
Yes, but it would be nice to attach some "parameter-comment" to the types no? Now a lot of documentation is written in the style "the 7th parameter is...". Not very user friendly :) Cheers, Peter