syntax_data: {"ast_node_type":"other","tokens":[{"end":57,"kind":"keyword","start":0,"text":"for"}]}
source_snippet:                     for field_pat in subpatterns.iter() {
context_before:                     print_indented!(self, "subpatterns: [", depth_lvl + 2);
context_after:                         self.print_pat(&field_pat.pattern, depth_lvl + 3);