Lack of generator return type inference

[deklanw]

Just noticed this while looking through the examples. Turns out it's a Typescript limitation which is going to be fixed soon (hopefully):

microsoft/TypeScript#2983
microsoft/TypeScript#30555

Just making an issue for it in anticipation.

[Jomik]

We do sort of fix this issue with our own typescript compiler plugin.
https://github.com/funkia/go-notation

[paldepind]

Unfortunately, I don't think any of the new features in TypeScript addresses this issue. As far as i can tell, even with the planned improvements the yield keyword will still always results in any 😭

[deklanw]

@Jomik
Thanks I'll try that out

@paldepind
I didn't look hard into the TS issue. Why will these changes not help?

[Jomik]

All the yield statements will still return any with the typescript update, so we can still not infer or typecheck the return value, so it does not help that much.

[deklanw]

I read more properly about generators/iterators and I understand better now. In case it helps someone else: it's because in general there is no connection between the Next type and Yield type.

Although, microsoft/TypeScript#30790 (comment)