Remove Iterator::advance

[bluss]

Unless I'm confused, Iterator::advance is actually exactly equivalent to Iterator::all.

We thus have two good reasons to remove it, 1) It's a legacy protocol 2) It's got an exact replacement in .all()

[ftxqxd]

Iterator::advance stops iterating at the first occurrence of a false value, while Iterator::all iterates over the entire iterator before stopping.

[huonw]

Yes, this should go.

@P1start no, both short-circuit. They are identical, the only difference is advance is written without the for, since it existed from before our new for protocol, and was the interface between the old and new iteration (for v.iter().advance |x| { ... }).

    fn advance(&mut self, f: |A| -> bool) -> bool {
        loop {
            match self.next() {
                Some(x) => {
                    if !f(x) { return false; }
                }
                None => { return true; }
            }
        }
    }

    fn all(&mut self, f: |A| -> bool) -> bool {
        for x in *self { if !f(x) { return false; } }
        true
    }

[luqmana]

I actually had I branch I was working on that I kinda forgot about (https://github.com/luqmana/rust/commits/die-advance-die) I'll update it and push it out.

[bluss]

@luqmana cool! It looks though as you can use .all() instead of explicit loops in many of your diff hunks.