esnext.map.find-key.js 898 B

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  1. 'use strict';
  2. var $ = require('../internals/export');
  3. var IS_PURE = require('../internals/is-pure');
  4. var anObject = require('../internals/an-object');
  5. var bind = require('../internals/function-bind-context');
  6. var getMapIterator = require('../internals/get-map-iterator');
  7. var iterate = require('../internals/iterate');
  8. // `Map.prototype.findKey` method
  9. // https://github.com/tc39/proposal-collection-methods
  10. $({ target: 'Map', proto: true, real: true, forced: IS_PURE }, {
  11. findKey: function findKey(callbackfn /* , thisArg */) {
  12. var map = anObject(this);
  13. var iterator = getMapIterator(map);
  14. var boundFunction = bind(callbackfn, arguments.length > 1 ? arguments[1] : undefined, 3);
  15. return iterate(iterator, function (key, value, stop) {
  16. if (boundFunction(value, key, map)) return stop(key);
  17. }, { AS_ENTRIES: true, IS_ITERATOR: true, INTERRUPTED: true }).result;
  18. }
  19. });