syntax_data: {"ast_node_type":"variable","tokens":[{"end":30,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:     let n = a.chars().count();
context_before: pub fn edit_distance_with_substrings(a: &str, b: &str, limit: usize) -> Option<usize> {
context_after:     let m = b.chars().count();