TypeHint for setter

[Naddiseo]

Probably doesn't need an explicit TypeHint, but semantics could state that settings are implicitly void.

[Naddiseo]

I added a TODO in the spec for the semantics behind this. Let's get some feedback from other spec writers regarding if it's needed.

[lukescott]

"Ensure setters are void" - does that mean you have to do:

class Foo {
  set value() void {

  }
}

If that's the case, shouldn't TypeHint be disallowed as a return on a setter? That would be more compatible with existing code.

Also, shouldn't a getter and setter be required to use the same TypeHint? As in:

This would be correct:

class Foo {
  get value() string {
    return this._value;
  }
  set value(v string) {
    this._value = v;
  }
}

But this would be invalid:

class Foo {
  get value() string {
    return this._value;
  }
  set value(v number) {
    this._value = v;
  }
}

I know this sort of type checking territory, but I ask because both methods share the same descriptor.

[Naddiseo]

The syntax allows empty, but if it's not empty, then it ensures that the return type is void. It's because I used parametized grammar, so it looks strange.

[lukescott]

Should void even be allowed on setter? Is the set keyword enough?

[Naddiseo]

set PropertyName[?Yield] ( PropertySetParameterList ) TypeHint[?Yield]opt { FunctionBody }

TypeHint is optional, so that generates two syntax rules, one with the TypeHint, and one without. The semantic checking only applies when it matches the line with the TypeHint.

Should void even be allowed on setter? Is the set keyword enough?

I added it in for symmetry. I think it would be surprising if it were forbidden.