Technically this is trivial it seems. I think that some people consider this proposal a problem because typos (misspelled type parameters) immediately lead to the accidental exploration of a more advanced type-system feature and correspondingly more involved error messages. Of course, the type checker could perhaps consider adding "Did you really mean to ...?". Ralf
I once read a paper about type classes and existentials (can't remember exact title or author, was it Läufer?) where the proposal was to make existential quantification implicit (just as the universal one is in Haskell98). That is, any type variable that appears on the rhs of a data type, but not on the lhs, is implicitly existentially quantified, as in
data XWrap = Show a => XWrap a
I always thought this was a pretty nice idea.