syntax_data: {"ast_node_type":"other","tokens":[{"end":52,"kind":"keyword","start":0,"text":"debug!(\"byte"}]}
source_snippet:                 debug!("byte is on line: {}", line);
context_before:                 debug!("char pos {:?} is on the line at char pos {:?}", chpos, linechpos);
context_after:                 assert!(chpos >= linechpos);