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

        private void ParseGroupName(int c, int terminator) {
            if (c == terminator || c == -1) {
                throw MakeError("group name is empty");
            }
            while (true) {
                Append((char)c); 
                c = Read();
                if (c == terminator || c == ')') {
                    Append((char)c);
                    break;
                } else if (c == -1) {
                    throw MakeError("unterminated group name");
                }
            }
        }