syntax_data: {"ast_node_type":"other","tokens":[{"end":45,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:     for (i, arg) in args.iter().enumerate() {
context_before:     let params_in_repr = tcx.params_in_repr(adt.did());
context_after:         if let ty::GenericArgKind::Type(ty) = arg.kind() {