query-extend.js
function(key) {
    var pos = key.indexOf('[');
    if (pos === -1) return { type: 'string', val: key };
    return { type: 'array', val: key.substr(0, pos) };
  }
function(key) {
    var pos = key.indexOf('[');
    if (pos === -1) return { type: 'string', val: key };
    return { type: 'array', val: key.substr(0, pos) };
  }
for now we will only support string and arrays