syntax_data: {"ast_node_type":"other","tokens":[{"end":73,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:         for (i, &(item_id, _)) in item_and_field_ids.iter().enumerate() {
context_before:         let mut s = String::new();
context_after:             let path = tcx.def_path_str(item_id);