IntervalParser.java 文件源码

/**
 * Parse an interval, for example <tt>[1,-]</tt> or <tt>-</tt> (a wildcard) or <tt>[1,4]</tt>.
 * Only fixed values are allowed, no variables.
 *
 * @param intervalAsString the string to be parsed.
 * @return a LowerBoundedInterval as the runtime representation of interval strings.
 * @throws ParseException in case the string doesn't fit the given fixed-interval grammar.
 */
public static LowerBoundedInterval parse(String intervalAsString) throws ParseException {
  CharStream charStream = new ANTLRInputStream(intervalAsString);
  CellExpressionLexer lexer = new CellExpressionLexer(charStream);
  TokenStream tokens = new CommonTokenStream(lexer);
  CellExpressionParser parser = new CellExpressionParser(tokens);
  parser.removeErrorListeners();
  parser.addErrorListener(new ThrowingErrorListener());
  try {
    CellExpressionParser.Fixed_intervalContext ctx = parser.fixed_interval();
    if (ctx == null) {
      throw new ParseException(0, 0, "Expected fixed interval");
    }
    return INSTANCE.visit(ctx);
  } catch (ParseRuntimeException runtimeException) {
    throw runtimeException.getParseException();
  }
}