Implict parameters and monomorphism

Dylan Thurston
Fri, 4 May 2001 16:16:29 -0400

On Fri, May 04, 2001 at 07:56:24PM +0000, Marcin 'Qrczak' Kowalczyk wrote:
> I would like to make pattern and result type signatures one-way
> matching, like in OCaml: a type variable just gives a name to the given
> part of the type, without constraining it any way - especially without
> "negative constraining", i.e. without yielding an error if it will
> be known more than that it's a possibly constrained type variable...

I'm not sure I understand here.  One thing that occurred to me reading
your e-mail was that maybe the implicit universal quantification over
type variables is a bad idea, and maybe type variables should, by
default, have pattern matching semantics.  Whether or not this is a
good idea abstractly, the way I imagine it, it would make almost all
existing Haskell code invalid, so it can't be what you're proposing.

Are you proposing that variables still be implicitly quantified in
top-level bindings, but that elsewhere they have pattern-matching

	Dylan Thurston