Yield as contextual keyword

[Tagir Valeev]

A small remark: when we advice to qualify the `yield` call to
distinguish it from YieldStatement, there's one corner case when
qualification is impossible. I mean a nested class inside an anonymous
class

var x = new Runnable() {
  public void run() {
    new Object() {
      void foo() {
        yield(1); // this.yield(1) or Runnable.this.yield(1) are incorrect.
      }
    }.foo();
  }
  void yield(int x) { System.out.println(x); }
};

I admit that such code is completely insane and probably doesn't exist
anywhere on the planet. Yet, the spec draft says:

> Any statement that begins with a reference to a field or method called yield can use its qualified name to ensure that the character sequence is not tokenized as a keyword.

Here 'Any' is not entirely correct.

With best regards,
Tagir Valeev.

On Sat, May 25, 2019 at 1:05 PM Tagir Valeev <amaembo at gmail.com> wrote:
>
> Hello!
>
> On Sat, May 25, 2019 at 4:44 AM Alex Buckley <alex.buckley at oracle.com> wrote:
> > On the other hand, the space after `:` is sometimes desirous of an
> > expression, so tokenize `yield` as a identifier: (and it might be the
> > name of a local variable, so no way to qualify)
> >
> > - `for (String s : yield . f) ...`
> >
> > - `m(a ? yield . f : yield . g)`
>
> Well to me it seems that `:` is no more special here than other listed
> tokens (probably except `}`). E.g.:
>
> - After `)`: ((Foo)yield).bar();
> - After `{`: Object[] arr = {yield};
> - After `;`: for(int i=0; i<10; yield(i++)) {}
>
> `yield` keyword is always preceded by one of X, Y, Z tokens doesn't
> mean that any `yield` character sequence which follows X, Y or Z
> tokens is necessarily a keyword. Only where YieldStatement production
> is expected we treat it as a keyword.
>
> Btw `yield` keyword can also appear after `else` token: if(foo) yield
> bar; else yield baz;
>
> With best regards,
> Tagir Valeev.