Feature request: use type constructors outside a module

[nekketsuuu]

Currently, we cannot construct a value of a variant type defined in a module, outside the module. I want to use these constructors.

Example:

module M = struct type t = A end

% We cannot use M.A here
% let x = M.A  % <-- ! [Syntax Error at Lexer]: illegal token '.' in a program area

% M.t itself can be used
let-rec forever () = forever ()
let x : M.t = forever ()  % pass the type checking

[nekketsuuu]

As of SATySFi 0.0.3, open of modules is implemented. Though the above example is failed as before, all examples in the following pass type checking.

% local open (1)
let x =
  open M in
  A

% local open (2)
let x = M.(A)

% global open
open M
let x = A