CreoleRenderer.java 文件源码

/**
 * Try to run a parser, resetting the input on failure.
 *
 * @param tokens The token stream. Consumed by the parser, and reset on
 *          failure.
 * @param parser The parser. Reset on failure.
 * @param pmode The prediction mode.
 * @return A parse tree.
 */
private static Optional<ParseTree> tryParse(final CommonTokenStream tokens, final Creole parser, final PredictionMode pmode) {
  parser.getInterpreter().setPredictionMode(pmode);

  try {
    return Optional.of((ParseTree) parser.creole());
  }
  catch (Exception e) {
    tokens.reset();
    parser.reset();

    return Optional.<ParseTree> absent();
  }
}