TokenizerMode.java

// inner class
private enum TokenizerMode {

    SPACE_DELIMITING (' '),
    QUOTE_DELIMITING ('\'', '"', '`');

    final char[] validDelimiters;
    static Map<Set<Character>, TokenizerMode> reverseLookup = new HashMap<>();
    static char[] allValidDelimiters;

    static {

        for (TokenizerMode mode: values()) {

            Set<Character> characterSet = new HashSet<>();

            for (char c: mode.getValidDelimiters()) {

                characterSet.add(c);

            }

            reverseLookup.put(characterSet, mode);

        }

    }

    TokenizerMode(char... validDelimiters) {

        this.validDelimiters = validDelimiters;

    }

    static char[] getAllValidDelimiters() {

        if (allValidDelimiters == null) {

            char[] allValidDelimiters = new char[reverseLookup.keySet().size()];

            for (int i = 0; i < allValidDelimiters.length; i++) {

                allValidDelimiters[i] = reverseLookup.keySet().toArray(new Character[0])[i];

            }

        }

        return allValidDelimiters;

    }

    boolean checkIfValidDelimiter(char character) {

        for (char c: validDelimiters) {

            if (c == character) return true;

        }

        return false;

    }

    char[] getValidDelimiters() {

        return validDelimiters;

    }

}