Re: [Caml-list] Newbie comment on constructor syntax

[Alain Frisch <alain.frisch@lexifi.com>]

On 10/11/2015 14:41, Romain Bardou wrote:
> I see: you do not just propose to have a way to extract a tuple from a
> multi-argument constructor. What you propose is to make all constructors
> have only 0 or 1 argument (which may be a tuple).

That's what already happen at the syntactic level.  I'm not proposing to 
change that, nor the interpretation of type declarations.  The change is 
how constructor expressions and patterns are type-checked (and 
compiled), in order to make transparent at these levels whether the 
constructor was defined as taking a tuple or several arguments.


> Under the hood, the
> tuple case is flattened to avoid an allocation, but the programmer does
> not have to know anymore (unless he uses Obj I guess).

He still needs to know, since:

  module X : sig    type t = A of int * int end
           = struct type t = A of (int * int) end

would still fail.


Alain