code: function() {
      var captures;
      if (captures = /^([()])([ \t]*)/.exec(this.str)) {
        var paren = captures[1];
        this.skip(captures);
        if (')' == paren) this.isURL = false;
        var tok = new Token(paren, paren);
        tok.space = captures[2];
        return tok;
      }
    }
docs: '(' | ')' ' '*