syntax_data: {"ast_node_type":"variable","tokens":[{"end":55,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:                     let field_ty = f_def.ty(tcx, args);
context_before:                 for (f_index, f_def) in v_def.fields.iter().enumerate() {
context_after:                     let field_ty = tcx