On Sat, Apr 13, 2013 at 09:00:22AM -0400, Sam Tobin-Hochstadt wrote: > The restriction is supposed to be that a type constructor T a = ... > can't have some field in the ... that's a use of T other than to apply > it to a. > > Unfortunately, this restriction (and all the other literature on this) > is presented for ML-like languages, which have neither structs like > TR, nor union types, nor subtyping. That's why we haven't been able > to easily transfer the literature on how to add non-regular data > types, and why I seem to have implemented an insufficiently-strong > restriction. > > So I think we need to think harder about this, but I don't have a > great suggestion for fixing it at the moment.
I believe Eiffel doesn't have this restriction. But my memory is vague, and I have no idea how they handled it. -- hendrik ____________________ Racket Users list: http://lists.racket-lang.org/users
