find_seqs_iterator.rs

struct Seqs<I> {
    iter: I,
}

impl<'a, I: Iterator<Item = &'a u8>> Iterator for Seqs<std::iter::Enumerate<I>> {
    type Item = (usize, usize);

    fn next(&mut self) -> Option<Self::Item> {
        // Jump to first byte '1'
        let start = loop {
            match self.iter.next() {
                Some((i, b'1')) => break i,
                None => return None,
                _ => (),
            }
        };

        // Find end
        let mut last_i = start;
        loop {
            match self.iter.next() {
                None => return Some((start, last_i + 1)),
                Some((i, b'0')) => return Some((start, i)),
                Some((i, _)) => last_i = i,
            }
        }
    }
}

fn main() {
    let x = b"00010110011100111100011111";

    let seqs = Seqs {
        iter: x.iter().enumerate(),
    };

    for seq in seqs {
        let _ = dbg!(std::str::from_utf8(&x[seq.0..seq.1]));
    }
}