--- /dev/null
+'use strict';
+var $ = require('../internals/export');
+var IS_PURE = require('../internals/is-pure');
+var getBuiltIn = require('../internals/get-built-in');
+var anObject = require('../internals/an-object');
+var aFunction = require('../internals/a-function');
+var bind = require('../internals/function-bind-context');
+var speciesConstructor = require('../internals/species-constructor');
+var getMapIterator = require('../internals/get-map-iterator');
+var iterate = require('../internals/iterate');
+
+// `Map.prototype.filter` method
+// https://github.com/tc39/proposal-collection-methods
+$({ target: 'Map', proto: true, real: true, forced: IS_PURE }, {
+ filter: function filter(callbackfn /* , thisArg */) {
+ var map = anObject(this);
+ var iterator = getMapIterator(map);
+ var boundFunction = bind(callbackfn, arguments.length > 1 ? arguments[1] : undefined, 3);
+ var newMap = new (speciesConstructor(map, getBuiltIn('Map')))();
+ var setter = aFunction(newMap.set);
+ iterate(iterator, function (key, value) {
+ if (boundFunction(value, key, map)) setter.call(newMap, key, value);
+ }, undefined, true, true);
+ return newMap;
+ }
+});