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Shout out to JavaScript massively delaying https://github.com/tc39/proposal-async-iterator-helpers https://github.com/tc39/proposal-async-iterator-helpers in th

Shout out to JavaScript massively delaying https://github.com/tc39/proposal-async-iterator-helpers https://github.com/tc39/proposal-async-iterator-helpers in the 23rd hour. The proposal seemed very close to getting shipped alongside https://github.com/tc39/proposal-iterator-helpers https://github.com/tc39/proposal-iterator-helpers while basically accepting many of the constraints of current async iteration (one at a time consumption). But the folks really accepted that concurrency needs had evolved, decided to hold back & keep iterating & churning for better. I feel like a lot of the easy visible mood on the web (against the web) is that there's too much, that stuff is just piled in. But I see a lot of caring & deliberation & trying to get shit right & good. Sometimes that too can be maddening, but ultimately with the web there aren't really re-do-es & the deliberation is good.

jacobolus 2y ago
You can implement quite a lot of Python's itertools in Javascript without too much trouble. For instance, https://observablehq.com/@jrus/itertools https://observablehq.com/@jrus/itertools Disclaimer: this code was written several years ago with few downstream users, not all of these are super high performing, and they have not been super extensively tested.
- raymondh 2y ago
  Your nice work on the JS itertools port has a todo for a "better tee". This was my fault because the old "rough equivalent" code in the Python docs was too obscure and didn't provide a good emulation. Here is an update that should be much easier to convert to JS: def tee(iterable, n=2): iterator = iter(iterable) shared_link = [None, None] return tuple(_tee(iterator, shared_link) for _ in range(n)) def _tee(iterator, link): try: while True: if link[1] is None: link[0] = next(iterator) link[1] = [None, None] value, link = link yield value except StopIteration: return
  - jacobolus 2y ago
    Thanks! And thanks, Raymond, for all your hard work over the years!
danpalmer 2y ago
> But the folks really accepted that concurrency needs had evolved, decided to hold back & keep iterating & churning for better I'm not sure if it was this proposal or another one in a similar space, but I've recently heard about several async improvements that were woefully under-spec'd, and would likely have caused much more harm than good due to all the edge cases that were missed.

jacobolus 2y ago

You can implement quite a lot of Python's itertools in Javascript without too much trouble. For instance, https://observablehq.com/@jrus/itertools https://observablehq.com/@jrus/itertools Disclaimer: this code was written several years ago with few downstream users, not all of these are super high performing, and they have not been super extensively tested.

raymondh 2y ago
Your nice work on the JS itertools port has a todo for a "better tee". This was my fault because the old "rough equivalent" code in the Python docs was too obscure and didn't provide a good emulation. Here is an update that should be much easier to convert to JS: def tee(iterable, n=2): iterator = iter(iterable) shared_link = [None, None] return tuple(_tee(iterator, shared_link) for _ in range(n)) def _tee(iterator, link): try: while True: if link[1] is None: link[0] = next(iterator) link[1] = [None, None] value, link = link yield value except StopIteration: return
- jacobolus 2y ago
  Thanks! And thanks, Raymond, for all your hard work over the years!

danpalmer 2y ago

> But the folks really accepted that concurrency needs had evolved, decided to hold back & keep iterating & churning for better I'm not sure if it was this proposal or another one in a similar space, but I've recently heard about several async improvements that were woefully under-spec'd, and would likely have caused much more harm than good due to all the edge cases that were missed.