Opinions on multiparameters on @@ functions

[crguezl]

@AdrianMoraRodriguez @PSantanaGlez13 @coromoto

I believe that multi-parameters must not be directly supported for assignable @@ functions, but
instead f(a,b,c) will be curried and synonymous for f(a)(b)(c).

An assignable @@ function must be always a function that takes a single parameter.

Thus, when presented with s.t. like:

function @@ foo(a, b, c) {
    return a + b + c;
}

console.log(foo(1, 2, 3)) // same as foo(1)(2)(3) = 6
console.log(foo(1, 5, 3)) // same as foo(1)(5)(3) = 9

The compiler, in the future, must produce the curried version of foo:

function @@ foo(a) {
    return @@ function(b) {
        return @@ function(c) {
            return a + b + c;
        }
    }
}

Currently it must produce a syntax error. S.t. like:

SyntaxError: examples/syntaxerror-many-parameters.js: Assignable functions are restricted to one parameter (2:0)

  1 | // May be in the future this will be a synonim of foo(a)(b) but by now let us throw an error
> 2 | function @@ foo(a, b) {
    | ^
  3 |   return a+b;
  4 | }
  5 | foo(a, b) = 5;
    at Parser._raise (/Users/casianorodriguezleon/campus-virtual/2324/research/parser-left-side-crguezl/packages/babel-parser/lib/index.js:705:17)