core/src/main/java/com/orientechnologies/common/parser/OBaseParser.java
protected int parserNextChars(final boolean iUpperCase, final boolean iMandatory, final String... iCandidateWords) {
    parserPreviousPos = parserCurrentPos;
    parserSkipWhiteSpaces();

    parserEscapeSequenceCount = 0;
    parserLastWord.setLength(0);

    final String[] processedWords = Arrays.copyOf(iCandidateWords, iCandidateWords.length);

    // PARSE THE CHARS
    final String text2Use = iUpperCase ? parserTextUpperCase : parserText;
    final int max = text2Use.length();

    parserCurrentPos = parserCurrentPos + parserTextUpperCase.length() - parserText.length();
    // PARSE TILL 1 CHAR AFTER THE END TO SIMULATE A SEPARATOR AS EOF
    for (int i = 0; parserCurrentPos <= max; ++i) {
      final char ch = parserCurrentPos < max ? text2Use.charAt(parserCurrentPos) : '\n';
      final boolean separator = ch == ' ' || ch == '\r' || ch == '\n' || ch == '\t' || ch == '(';
      if (!separator)
        parserLastWord.append(ch);

      // CLEAR CANDIDATES
      int candidatesWordsCount = 0;
      int candidatesWordsPos = -1;
      for (int c = 0; c < processedWords.length; ++c) {
        final String w = processedWords[c];
        if (w != null) {
          final int wordSize = w.length();
          if ((separator && wordSize > i) || (!separator && (i > wordSize - 1 || w.charAt(i) != ch)))
            // DISCARD IT
            processedWords[c] = null;
          else {
            candidatesWordsCount++;
            if (candidatesWordsCount == 1)
              // REMEMBER THE POSITION
              candidatesWordsPos = c;
          }
        }
      }

      if (candidatesWordsCount == 1) {
        // ONE RESULT, CHECKING IF FOUND
        final String w = processedWords[candidatesWordsPos];
        if (w.length() == i + (separator ? 0 : 1) && !Character.isLetter(ch))
          // FOUND!
          return candidatesWordsPos;
      }

      if (candidatesWordsCount == 0 || separator)
        break;

      parserCurrentPos++;
    }

    if (iMandatory)
      throwSyntaxErrorException("Found unexpected keyword '" + parserLastWord + "' while it was expected '"
          + Arrays.toString(iCandidateWords) + "'");

    return -1;
  }
protected int parserNextChars(final boolean iUpperCase, final boolean iMandatory, final String... iCandidateWords) {
    parserPreviousPos = parserCurrentPos;
    parserSkipWhiteSpaces();

    parserEscapeSequenceCount = 0;
    parserLastWord.setLength(0);

    final String[] processedWords = Arrays.copyOf(iCandidateWords, iCandidateWords.length);

    // PARSE THE CHARS
    final String text2Use = iUpperCase ? parserTextUpperCase : parserText;
    final int max = text2Use.length();

    parserCurrentPos = parserCurrentPos + parserTextUpperCase.length() - parserText.length();
    // PARSE TILL 1 CHAR AFTER THE END TO SIMULATE A SEPARATOR AS EOF
    for (int i = 0; parserCurrentPos <= max; ++i) {
      final char ch = parserCurrentPos < max ? text2Use.charAt(parserCurrentPos) : '\n';
      final boolean separator = ch == ' ' || ch == '\r' || ch == '\n' || ch == '\t' || ch == '(';
      if (!separator)
        parserLastWord.append(ch);

      // CLEAR CANDIDATES
      int candidatesWordsCount = 0;
      int candidatesWordsPos = -1;
      for (int c = 0; c < processedWords.length; ++c) {
        final String w = processedWords[c];
        if (w != null) {
          final int wordSize = w.length();
          if ((separator && wordSize > i) || (!separator && (i > wordSize - 1 || w.charAt(i) != ch)))
            // DISCARD IT
            processedWords[c] = null;
          else {
            candidatesWordsCount++;
            if (candidatesWordsCount == 1)
              // REMEMBER THE POSITION
              candidatesWordsPos = c;
          }
        }
      }

      if (candidatesWordsCount == 1) {
        // ONE RESULT, CHECKING IF FOUND
        final String w = processedWords[candidatesWordsPos];
        if (w.length() == i + (separator ? 0 : 1) && !Character.isLetter(ch))
          // FOUND!
          return candidatesWordsPos;
      }

      if (candidatesWordsCount == 0 || separator)
        break;

      parserCurrentPos++;
    }

    if (iMandatory)
      throwSyntaxErrorException("Found unexpected keyword '" + parserLastWord + "' while it was expected '"
          + Arrays.toString(iCandidateWords) + "'");

    return -1;
  }
Parses the next sequence of chars.

@return The position of the word matched if any, otherwise -1 or an exception if iMandatory is true