syntax_data: {"ast_node_type":"variable","tokens":[{"end":67,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let field_name = coroutine.field_names[*local];
context_before:                 .map(|(field_idx, local)| {
context_after:                     let field_layout = variant_layout.field(cx, field_idx);