IronRuby.Builtins.RegexpTransformer.ParseConstrainedQuantifier C# (CSharp) Method

        private bool ParseConstrainedQuantifier() {
            Debug.Assert(_rubyPattern[_index - 1] == '{');

            int c;
            int m = -1;

            int i = 0;
            while (true) {
                c = Peek(i++);
                if (c == ',') {
                    if (m != -1) {
                        // not a quantifier
                        return false;
                    }
                    m = i;                    
                } else if (c == '}') {
                    break;
                } else if (!Tokenizer.IsDecimalDigit(c)) {
                    return false;
                }
            }

            _sb.Append(_rubyPattern, _index - 1, i + 1);
            _index += i;
            return true;
        }