>>>This unfortunate syntax has consequences down to polymorphic variants,
>>>which otherwise could be represented more efficiently.
>>>
>>
>>This is interesting, could you explain it shortly?
> 
> 
> The tuple based syntax for constructors is ambiguous: there is no way
> to know syntactically whether a constructor takes as argument a tuple
> or separate arguments. This is the reason for this whole discussion.

Yes this is not a very big problem but is quite often reported.
The reason I see is that (int * int) and int * int are perceived the 
same because parenthesis are optional when applying the * operator in 
calculus.

In order to fix this, I choose to always have parenthesis for multiple 
arguments constructors in NekoML :

type a {
    A : int;
    B : (int , int); // 2 arguments
    C : ((int , int)); // 1 tuple argument
}

It is then more easy to understand the difference between B and C, 
although this is in the end just a matter of using an appropriate 
syntax. The parenthesis are just abusely used in different manners in 
most of languages syntax.

Nicolas