syntax_data: {"ast_node_type":"variable","tokens":[{"end":22,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let elem =
context_before:         for (idx, subpattern) in prefix.iter().enumerate() {
context_after:                 ProjectionElem::ConstantIndex { offset: idx as u64, min_length, from_end: false };