Method add

src/main/java/org/apache/commons/lang3/CharSet.java:189–216

Add a set definition string to the CharSet. @param str set definition string

(final String str)

     * @param str  set definition string
     */
    protected void add(final String str) {
        if (str == null) {
            return;
        }

        final int len = str.length();
        int pos = 0;
        while (pos < len) {
            final int remainder = len - pos;
            if (remainder >= 4 && str.charAt(pos) == '^' && str.charAt(pos + 2) == '-') {
                // negated range
                set.add(CharRange.isNotIn(str.charAt(pos + 1), str.charAt(pos + 3)));
                pos += 4;
            } else if (remainder >= 3 && str.charAt(pos + 1) == '-') {
                // range
                set.add(CharRange.isIn(str.charAt(pos), str.charAt(pos + 2)));
                pos += 3;
            } else if (remainder >= 2 && str.charAt(pos) == '^') {
                // negated char
                set.add(CharRange.isNot(str.charAt(pos + 1)));
                pos += 2;
            } else {
                // char
                set.add(CharRange.is(str.charAt(pos)));
                pos += 1;
            }
        }
    }

    //-----------------------------------------------------------------------
    /**