We do not have first-class iterators, but we do have an iterator pattern which is common throughout the Hare standard library. As an example, here's how you can enumerate the nodes in a directory:
let iter = os::iter("/")!;
for (true) {
const entry = match (fs::next(&iter)) {
case let ent: fs::dirent =>
yield ent;
case void =>
break;
};
fs::println(entry.name)!;
};
I understand not having first-class iterators; Rust traits encourage using option/iterator combinator methods rather than imperative code, which I find unclear in nearly all cases (though iterator reduce() is better at finding the min/max of a sequence, since you don't have to initialize the counter to a sentinel value). I was discussing the use of coroutines for building iterators, for example implementing the next function for a recursive filesystem glob or B-tree map iterator or database table join, which I find miserable and bug-prone to write by hand.
