static GazelleV_LeftArrowScript.Script leftArrowParseVerbose(S script) {
  new GazelleV_LeftArrowScriptParser parser;
  enableScaffolding(parser);
  parser.allowTheWorld();
  var parsedScript = parser.parse(script);
  print("leftArrowParseVerbose:\n" + GazelleV_LeftArrowScript.indentedScriptStruct(parsedScript));
  ret parsedScript;
}

Began life as a copy of #1034203