code: function parseObjectPattern (inp) {
      var res = parseKey(inp);
      if (res) {
        if (inp.skipWs().takeAPeek(":")) {
          var patt = parsePattern(inp.skipWs());
          if (patt) return nodeKeyValue(res, patt);
        }
        return nodeKey(res);
      }
    }
docs: Objects can only contain keys or key-value pairs.