{"ast_node_type":"variable","tokens":[{"end":96,"kind":"keyword","start":0,"text":"let"}]}
    let marker: fn(char) -> bool = if line.contains('^') { |c| c == '^' } else { |c| c == '|' };
    let mut offset: TextSize = 0.into();
    while let Some(idx) = line.find(marker) {