about value polymorphism '_a
- I've sent in this list several messages concerning the _ in types such
as in '_a or _[`A].
This restriction of polymorphism to syntactical values has been
developped in "Simple Imperative polymorphism" by Andrew K. Wright (in
Lisp and Symbolic Computation 1995).
Jacques Garrigue wrote an interresting article about this subject (see
his home page) and made a relaxation of the restriction.
This relaxation should be included in a next release of ocaml.
Example : (fun x -> x)  will be a 'a list instead of a '_a list.