syntax_data: {"ast_node_type":"variable","tokens":[{"end":50,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let place = place.clone_project(elem);
context_before:                 ProjectionElem::ConstantIndex { offset: idx as u64, min_length, from_end: false };
context_after:             MatchPairTree::for_pattern(place, subpattern, self, match_pairs, extra_data)