Helper to determine the constructor for an instance, given a namesapce

constructor_getter.js

var constructor_getter = (function() {
  var parser = function(ns, instance) {
    for (var key in ns) {
      try {
        if (instance instanceof ns[key]) {
          return key;
        }
      } catch (err) {}
    }
  };
  return function(ns, instance) {
    console.log(parser(ns, instance));
  }
}());