take_until_bytes() and partial parsing

[simpsoneric]

take_until_bytes() and partial parsing

[Marwes]

Fixed the state issue in #328 but you generally shouldn't call parse_with_state explicitly, just incorporate the take_until_bytes/range parser before your other parser and call parse as normal (let the state be an implementation detail. To drop the output of take_until_bytes you can just wrap that parser with ignore or .map(|_| ())

[simpsoneric]

Fantastic, thanks for the quick fix! My test case passes the above code and your new issue_327 branch.

Thanks for the insight on letting the state be an implementation detail wrapped by the internal state. I am struggling figure out what data structure I can use as a test source that approach though. For example:

pub fn parser5() {

    let sync = [1u8, 2, 3, 4, 5];
    let prefix_data = [9u8, 9];
    let mut buf = BytesMut::with_capacity(64);

    // Add random prefix data
    buf.extend_from_slice(&prefix_data);

    // Add partial sync sequence
    buf.extend_from_slice(&sync[..sync.len()-1]);

    let mut prefix_parser = take_until_range(&sync[..]);
    {
        // Should be able to drop first items from input stream
        let r  = prefix_parser.parse(PartialStream(&buf[..])); // <-- `buf` immutable borrow first occurs here
        dbg!(r);
    }
    {
        // Add last item from the sync sequence
        buf.put_u8(sync[sync.len()-1]); // <-- Error: cannot borrow mutable due to above immutable borrow

        let r  = prefix_parser.parse(PartialStream(&buf[..]));
        dbg!(r);
    }
}

If you don't mind giving some advice on how this should be approached, I'd appreciate it. Otherwise, I'll start digging around the code/docs some more.