{"ast_node_type":"variable","tokens":[{"end":60,"kind":"keyword","start":0,"text":"let"}]}
    let mut push_err = |prefix_len, off, err: EscapeError| {
    // FIXME: lift this lambda refactor to `fn` (https://github.com/rust-lang/rust-analyzer/pull/2834#discussion_r366199205)
        let off = token.text_range().start() + TextSize::try_from(off + prefix_len).unwrap();