prepack/lib/intrinsics/ecma262/ArrayIteratorPrototype.js

Execute a JS bundle, serialize global state and side effects to a snapshot that can be quickly restored.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;

var _singletons = require("../../singletons.js");

var _index = require("../../values/index.js");

var _get = require("../../methods/get.js");

var _invariant = _interopRequireDefault(require("../../invariant.js"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

/*  strict-local */
function _default(realm, obj) {
  // ECMA262 22.1.5.2.1
  obj.defineNativeMethod("next", 0, context => {
    // 1. Let O be the this value.
    let O = context.throwIfNotConcrete(); // 2. If Type(O) is not Object, throw a TypeError exception.

    if (!(O instanceof _index.ObjectValue)) {
      throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError, "not an object");
    } // 3. If O does not have all of the internal slots of an Array Iterator Instance (22.1.5.3), throw a TypeError exception.


    if (O.$IteratedObject === undefined || O.$ArrayIteratorNextIndex === undefined || O.$ArrayIterationKind === undefined) {
      throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError, "ArrayIteratorPrototype.next isn't generic");
    } // 4. Let a be the value of the [[IteratedObject]] internal slot of O.


    let a = O.$IteratedObject;
    (0, _invariant.default)(a instanceof _index.ObjectValue || a instanceof _index.UndefinedValue); // 5. If a is undefined, return CreateIterResultObject(undefined, true).

    if (a instanceof _index.UndefinedValue) {
      return _singletons.Create.CreateIterResultObject(realm, realm.intrinsics.undefined, true);
    } // 6. Let index be the value of the [[ArrayIteratorNextIndex]] internal slot of O.


    let index = O.$ArrayIteratorNextIndex.value; // 7. Let itemKind be the value of the [[ArrayIterationKind]] internal slot of O.

    let itemKind = O.$ArrayIterationKind; // 8. If a has a [[TypedArrayName]] internal slot, then

    let len;

    if (a.$TypedArrayName) {
      // a. Let len be the value of a's [[ArrayLength]] internal slot.
      len = a.$ArrayLength;
      (0, _invariant.default)(typeof len === "number");
    } else {
      // 9. Else,
      // a. Let len be ? ToLength(? Get(a, "length")).
      len = _singletons.To.ToLength(realm, (0, _get.Get)(realm, a, "length"));
    } // 10. If index ≥ len, then


    if (index >= len) {
      // a. Set the value of the [[IteratedObject]] internal slot of O to undefined.
      O.$IteratedObject = realm.intrinsics.undefined; // b. Return CreateIterResultObject(undefined, true).

      return _singletons.Create.CreateIterResultObject(realm, realm.intrinsics.undefined, true);
    } // 11. Set the value of the [[ArrayIteratorNextIndex]] internal slot of O to index+1.


    O.$ArrayIteratorNextIndex = new _index.NumberValue(realm, index + 1); // 12. If itemKind is "key", return CreateIterResultObject(index, false).

    if (itemKind === "key") {
      return _singletons.Create.CreateIterResultObject(realm, new _index.NumberValue(realm, index), false);
    } // 13. Let elementKey be ! ToString(index).


    let elementKey = new _index.StringValue(realm, index + ""); // 14. Let elementValue be ? Get(a, elementKey).

    let elementValue = (0, _get.Get)(realm, a, elementKey); // 15. If itemKind is "value", let result be elementValue.

    let result;

    if (itemKind === "value") {
      result = elementValue;
    } else {
      // 16. Else,
      // a. Assert: itemKind is "key+value".
      (0, _invariant.default)(itemKind === "key+value", "expected item kind to be key+value"); // b. Let result be CreateArrayFromList(« index, elementValue »).

      result = _singletons.Create.CreateArrayFromList(realm, [new _index.NumberValue(realm, index), elementValue]);
    } // 17. Return CreateIterResultObject(result, false).


    return _singletons.Create.CreateIterResultObject(realm, result, false);
  }); // ECMA262 22.1.5.2.2

  obj.defineNativeProperty(realm.intrinsics.SymbolToStringTag, new _index.StringValue(realm, "Array Iterator"), {
    writable: false
  });
}
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