[CSSer]

Interestingly, the thread you linked to also has links to other discussions where the React.js team provide their reasoning for why they decided against using generators[0] that the author of Crank.js didn't mention in their post. There's also a more basic breakdown of that explanation deeper in the twitter thread here[1]. As I understand it (and I am no expert), Crank.js's usage of generators is not the most performant because it doesn't provide an avenue to avoid recalcing work. In this case, memoization/caching does nothing to save you.

There are also other interesting tradeoffs, like suddenly making everything a generator as a result (as seen here). It's not that big of a deal to me, personally, but it's not something that everyone in the JS world is necessarily used to either.

Overall, it seems to be about target audience and priorities. Facebook seems to really care about intense performance at scale and they want all of their developers to be able to use their framework with ease. It seems they don't mind if that means requiring a bit of their own 'dogmatic' education as the author put it. Regardless, I agree. This is really interesting stuff!

[0]https://github.com/facebook/react/issues/7942#issuecomment-2... [1]https://twitter.com/swyx/status/1244749594472243200 (see @samselikoff's reply and following discussion)