21 lines
854 B
JavaScript
21 lines
854 B
JavaScript
|
'use strict';
|
||
|
|
var $ = require('../internals/export');
|
||
|
|
var IS_PURE = require('../internals/is-pure');
|
||
|
|
var anObject = require('../internals/an-object');
|
||
|
|
var bind = require('../internals/bind-context');
|
||
|
|
var getMapIterator = require('../internals/get-map-iterator');
|
||
|
|
var iterate = require('../internals/iterate');
|
||
|
|
|
||
|
|
// `Map.prototype.findKey` method
|
||
|
|
// https://github.com/tc39/proposal-collection-methods
|
||
|
|
$({ target: 'Map', proto: true, real: true, forced: IS_PURE }, {
|
||
|
|
findKey: function findKey(callbackfn /* , thisArg */) {
|
||
|
|
var map = anObject(this);
|
||
|
|
var iterator = getMapIterator(map);
|
||
|
|
var boundFunction = bind(callbackfn, arguments.length > 1 ? arguments[1] : undefined, 3);
|
||
|
|
return iterate(iterator, function (key, value) {
|
||
|
|
if (boundFunction(value, key, map)) return iterate.stop(key);
|
||
|
|
}, undefined, true, true).result;
|
||
|
|
}
|
||
|
|
});
|