'use strict'; var aSet = require('../internals/a-set'); var SetHelpers = require('../internals/set-helpers'); var size = require('../internals/set-size'); var getSetRecord = require('../internals/get-set-record'); var iterateSet = require('../internals/set-iterate'); var iterateSimple = require('../internals/iterate-simple'); var Set = SetHelpers.Set; var add = SetHelpers.add; var has = SetHelpers.has; var nativeHas = SetHelpers.$has; var nativeKeys = SetHelpers.$keys; var isNativeSetRecord = function (record) { return record.has === nativeHas && record.keys === nativeKeys; }; // `Set.prototype.intersection` method // https://github.com/tc39/proposal-set-methods module.exports = function intersection(other) { var O = aSet(this); var otherRec = getSetRecord(other); var result = new Set(); // observable side effects if (!isNativeSetRecord(otherRec) && size(O) > otherRec.size) { iterateSimple(otherRec.getIterator(), function (e) { if (has(O, e)) add(result, e); }); if (size(result) < 2) return result; var disordered = result; result = new Set(); iterateSet(O, function (e) { if (has(disordered, e)) add(result, e); }); } else { iterateSet(O, function (e) { if (otherRec.includes(e)) add(result, e); }); } return result; };