Allow all types as a key in $PropertyType.

[pvolok]

No description provided.

[pvolok]

Fixed build error in gc_js.ml. Now CI should pass.

[facebook-github-bot]

@samwgoldman has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[samwgoldman]

Oh, interesting. It looks like the rules for InstanceT _, (GetElemT _ | SetElemT _) are a bit dumb and don't attempt to convert statically-known strings to named property lookups the way the corresponding rules for ObjT do.

Without that, code like this fails unexpectedly:

class C { p: number }
(0: $PropertyType<C, 'p'>);

If you are interested in something else to work on, we'd definitely need to resolve this issue before landing this change. If you're busy, I would be happy to take it on.

[pvolok]

Thanks for reviewing! I will finish it. Need this for relay typings.

…

On Dec 14, 2016, at 3:31 AM, Sam Goldman ***@***.***> wrote: Oh, interesting. It looks like the rules for InstanceT _, (GetElemT _ | SetElemT _) are a bit dumb and don't attempt to convert statically-known strings to named property lookups the way the corresponding rules for ObjT do. Without that, code like this fails unexpectedly: class C { p: number } (0: $PropertyType<C, 'p'>); If you are interested in something else to work on, we'd definitely need to resolve this issue before landing this change. If you're busy, I would be happy to take it on. — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[szagi3891]

Why do not you integrate this PR?

[TheXardas]

I also need this feature as well!
When is it going to be merged?

[szagi3891]

@pvolok @samwgoldman
Do you have any plans for this "PR"?
This functionality will be very useful.

[bradencanderson]

Was this fixed in 968210c?

Demo (try on master):
https://flow.org/try/#0PTAEBIFEBsFMFtYDsAuAVAngB1gHjQDSgDOKATgJZIDmAfKAIYDGKxjbKAFrKCtjwHsAZr24lyVaqFhxEqNlVACARgCtYLXv1BoAULr45QAQTJlQAXhNmGGXEgCu8ZbDK0A3Ae2myAfRgIlhABcuj8uD5Ejs6uHvoAFAAsAEwAXNZ+IQCU7qAgoADyANLpAAY+-rKloBRspdEuZKW68QDk3NDQAqAA7gJk0AAmrekV2Z66Qg5ILBQCSKBCAgLxDKNmWelQsshhOBFmUU6N9ADeuqA1IvFCDNDEsFmgZLAoDmQLDADaAAwAup5LjIHs9Xu8Fj9PABffQgOHwhGIpH6Qw8ApqIKnUBfADWsAw6VIlBof3SDVcoChnlRhTUlUCVm2CF2mH26NURCJkjiLRS6XZ9PgOTyYGKZQFIWqtVA9WOrmabQ6XV6-SGI1pqkFOX0UxmKDmC2UDDI8QE-LUm2CO1QrLw7M5EhoZwuV1ANzuDyeLzeHyUX1aygcAC9WgCXcCeN7waBIboYbokYmk3D9LomNAGMQ2MZQOdLlgyAIsMZCY7qIDQEx5kSHCx+vEnnnLqJagA6AtFnNWVrGVoVmHx9OZtgAIVzLo7WBHZLlZArVaQNbrJsbLsuXDbk7HVgAjP24-oF6RQPAGFhMcYiCOqZNprN5s8BA4UHgivjS8S6PE8QTQG+MJaTKhLauCosIJ5nkQ-7OpcUa+qeWC4viYaDtWKCMB+khBG6SCwD0bqFs+sBtL2WRZA2WTtoWxYiqASDdK4hZkGmaGgMokBmP0M4xOYVg4XhBFPi+bQjq0ZEUVRna0Yx-QsYu6HKNxjTYfEuH4fEhHCa0oniWRklTrR9HSJxzGXLoQA

[asazernik]

@bradencanderson Or, for an example that may be more relevant to many followers of this issue:

class Record<Members: Object> {
  data: Members;

  constructor(data: Members) {
    this.data = data;
  }
  
  get<Key: string>(k: Key): $ElementType<Members, Key> {
      return this.data[k];
  }
}


type Thing = {
  a: number,
  b: string,
}
const constructorFailure: Record<Thing> = new Record({a: 1}) // error 
const r: Record<Thing> = new Record({a: 1, b: 'foo'});

(r.get('a'): string); // error
(r.get('a'): number);
(r.get('b'): number); // error
(r.get('b'): string);

In the sandbox.

[yachaka]

$ElementType definitely is the solution. Do you have an idea if this will be released with 0.49?

[sergey-lapin]

@pvolok why it is closed? My guess you are not able to work on this anymore - can you comment if this is the case?

[pvolok]

@Lapanoid Looks like $ElementType fixes the problem. Not sure if it works with classes though.

[sergey-lapin]

@pvolok Ahh I see, I thought it is released already, but it is only in master currently

[asazernik]

@Lapanoid Yeah, only landed in master on Sunday :-P