Re: [RFC] Allow object keys in arrays

Hi Matthew On Wed, Jan 13, 2021 at 7:15 AM Matthew Brown <matthewmatthew@gmail.com> wrote: > > This proposal is interesting, and I see why the enum proposal makes it > useful. > > Supporting this will mean a small amount of work for me (assuming it > passes) and other static analysis tools, but I don't want that to factor > into anyone's decision. > > I am curious, though, whether the scope of this RFC could be narrowed to > just allowing enum cases as keys? That might avoid issues with objects that > cannot be cast to string. The enum RFC currently does not propose auto-implementing __toString() and actually forbids implementing __toString() manually in case we want to add some type of coercion at some point. While we could change that, I do think it introduces some inconsistencies. enum Foo: string { case Bar = 'bar'; } var_dump(Foo::Bar . 'baz'); // barbaz enum Foo: int { case Bar = 1; } var_dump(Foo::Bar + 2); // Type error // Will require Foo::Bar->value to work We intentionally removed auto-coercion from enums because the rules are complicated and not clear-cut, and type strictness is what the language generally seems to be striving towards. That is not to say narrowing object keys to enums is a bad idea. I think that might be worth considering for other reasons. Ilija