syntax_data: {"ast_node_type":"other","tokens":[{"end":6,"kind":"keyword","start":0,"text":"};"}]}
source_snippet:     };
context_before:         $opt_expr.gather_target_modifiers($mods, $tmod_vals);
context_after:     ($opt_name:ident, $opt_expr:expr, $mods:expr, $tmod_vals:expr, [$non_substruct:ident TARGET_MODIFIER]) => {