Function fnptr_paren_tail

codegraph-kernel/src/cfnptr.rs:305–335

`\(\s*(?:\w+\s+)*\*\s*(\w+)\s*\)\s*\(` matched at `open` (which must hold `(`). Returns (name_range, end_after_second_paren). The `(?:\w+\s+)*` group is greedy without backtracking: giving back an iteration repositions `\*` onto a word char, which can never match, so greedy ≡ backtracked.

(s: &[u8], open: usize)

/// `(`). Returns (name_range, end_after_second_paren). The `(?:\w+\s+)*`
/// group is greedy without backtracking: giving back an iteration repositions
/// `\*` onto a word char, which can never match, so greedy ≡ backtracked.
fn fnptr_paren_tail(s: &[u8], open: usize) -> Option<((usize, usize), usize)> {
    let mut i = skip_jsws(s, open + 1);
    loop {
        if !is_word_at(s, i) {
            break;
        }
        let we = word_end(s, i);
        let wse = skip_jsws(s, we);
        if wse == we {
            break; // \w+ not followed by \s+ — the iteration fails, word not consumed
        }
        i = wse;
    }
    if s.get(i) != Some(&b'*') {
        return None;
    }
    i = skip_jsws(s, i + 1);
    if !is_word_at(s, i) {
        return None;
    }
    let name = (i, word_end(s, i));
    i = skip_jsws(s, name.1);
    if s.get(i) != Some(&b')') {
        return None;
    }
    i = skip_jsws(s, i + 1);
    if s.get(i) != Some(&b'(') {
        return None;
    }
    Some((name, i + 1))
}

/// `\s*\)?\s*\(` at `i` → position after the `(`. The optional `)` needs no