Editorial convention: Yield vs GeneratorYield

[nicolo-ribaudo]

Looking through built-in functions defined as generators, some of them use Yield() while other use GeneratorYield(). There doesn't seem to be a clear rule about which one to use when. For example:

• 7 uses of Yield(), out of which two are for yield; and yield expr;
• 9 uses of GeneratorYield(), out of which one is in Yield() and three in yield* expr
• AsyncGeneratorYield() is only used in Yield() and yield* expr
• https://tc39.es/ecma262/#sec-generatorstart introduces 4 more usages of Yield()

The difference between Yield() and GeneratorYield()/AsyncGeneratorYield() is that Yield() first checks if we are in a sync or async generator, and then dispatches to the right AO.

It'd be great if there was a consistent guideline around it. Either:

• Always use Yield(). GeneratorYield()/AsyncGeneratorYield() are only called by Yield() itself.
• Always use the correct one between GeneratorYield()/AsyncGeneratorYield(), whenever it's know whether we are in a sync or async built-in generator. Yield() would only be used to implement the actual yield syntax.

[nicolo-ribaudo]

All the usages of Yield in sync built-in generators happens in iterator helpers.

[michaelficarra]

I had noticed this inconsistency in the past and considered your latter proposal:

Always use the correct one between GeneratorYield()/AsyncGeneratorYield(), whenever it's know whether we are in a sync or async built-in generator. Yield() would only be used to implement the actual yield syntax.

but subsequently forgot to follow up. I'd prefer this direction unless there's some shared behaviour we're going to want to add (such as for https://github.com/tc39/proposal-async-context-disposable), in which case it'd probably be better to go the other way around.

[nicolo-ribaudo]

I also prefer the second approach.

The AsyncContext proposals are likely to hook directly into the syntax, to avoid exposing wether some built-in iterator is editorially written with the generator utilities or manually.