> "Single-use iterators" break that convention, providing the ability to walk a sequence only once.
This seems similar to the difference between an "iterable" and an "iterator" in Python (and between `IEnumerable` and `IEnumerator` in C#).
A Python list `l = [1, 2, 3]` is an iterable, and you can do `for v in l: print(v)` multiple times. But `iter(l)` is an iterator and `for v in i: print(v)` will only work once.
At least it's pretty easy to wrap an iterator in JS:
{[Symbol.iterator]: () => it}
Basically what Go calls an iterator most other language call an iterable. Because it uses internal iteration, Go doesn't hand out iterators (save through iter.Pull).
- impure iterators are strictly more powerful than pure iterators in that they can be resumed but do not have to be. If I wanted to pick one pattern for consistent behavior across all iterators it would be this one.
Makes sense
> Not all impure iterators can be resumed
How do you mean? In my head resuming an iterator is just partially unrolling a loop.
tapirl•8mo ago
jub0bs•8mo ago
tapirl•8mo ago
jub0bs•8mo ago