CocoRoboDesktop/pdf.js/node_modules/underscore/amd/_methodFingerprint.js

define(['exports', './_getLength', './isFunction', './allKeys'], function (exports, _getLength, isFunction, allKeys) {

  // Since the regular `Object.prototype.toString` type tests don't work for
  // some types in IE 11, we use a fingerprinting heuristic instead, based
  // on the methods. It's not great, but it's the best we got.
  // The fingerprint method lists are defined below.
  function ie11fingerprint(methods) {
    var length = _getLength(methods);
    return function(obj) {
      if (obj == null) return false;
      // `Map`, `WeakMap` and `Set` have no enumerable keys.
      var keys = allKeys(obj);
      if (_getLength(keys)) return false;
      for (var i = 0; i < length; i++) {
        if (!isFunction(obj[methods[i]])) return false;
      }
      // If we are testing against `WeakMap`, we need to ensure that
      // `obj` doesn't have a `forEach` method in order to distinguish
      // it from a regular `Map`.
      return methods !== weakMapMethods || !isFunction(obj[forEachName]);
    };
  }

  // In the interest of compact minification, we write
  // each string in the fingerprints only once.
  var forEachName = 'forEach',
      hasName = 'has',
      commonInit = ['clear', 'delete'],
      mapTail = ['get', hasName, 'set'];

  // `Map`, `WeakMap` and `Set` each have slightly different
  // combinations of the above sublists.
  var mapMethods = commonInit.concat(forEachName, mapTail),
      weakMapMethods = commonInit.concat(mapTail),
      setMethods = ['add'].concat(commonInit, forEachName, hasName);

  exports.ie11fingerprint = ie11fingerprint;
  exports.mapMethods = mapMethods;
  exports.setMethods = setMethods;
  exports.weakMapMethods = weakMapMethods;

  Object.defineProperty(exports, '__esModule', { value: true });

});