[wg-camlp4] About the "bool" argument fo Ppat_construct and Pexp_construct

[Alain Frisch]

Dear all,

The Ppat_construct and Pexp_construct constructors in Parsetree have a 
"bool" argument supposed to encode the fact that if the argument is a 
tuple of length N, then it actually represents the N arguments of an 
N-ary constructor, so that it won't type-check if the constructor is 
declared with a single argument being a N-tuple type.  (In the normal 
OCaml syntax, this cannot be distinguished.)

I believe this was introduced to give better error messages with Camlp4 
revised syntax, but the behavior seems to be disabled by default (can 
anyone confirm?) and I don't see how to enable it.  The following is 
accepted if we compile with camlp4:

=======================================
type t = [C of (int * int)];

value f = fun [ C x y -> x + y ];
=======================================

and I believe rejecting this was the reason to introduce the Boolean.


Does anyone object to removing the Boolean?

Alain