prepack/lib/methods/iterator.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.GetIterator = GetIterator;
exports.IteratorStep = IteratorStep;
exports.IteratorValue = IteratorValue;
exports.IteratorComplete = IteratorComplete;
exports.IteratorNext = IteratorNext;
exports.CreateListIterator = CreateListIterator;
exports.CreateMapIterator = CreateMapIterator;
exports.CreateSetIterator = CreateSetIterator;
exports.IteratorClose = IteratorClose;
exports.IterableToList = IterableToList;

var _completions = require("../completions.js");

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

var _index2 = require("./index.js");

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

var _abstract = require("./abstract.js");

var _singletons = require("../singletons.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 */
// ECMA262 7.4.1
function GetIterator(realm, obj = realm.intrinsics.undefined, _method) {
  let method = _method; // 1. If method was not passed, then

  if (!method) {
    // a. Let method be ? GetMethod(obj, @@iterator).
    method = (0, _index2.GetMethod)(realm, obj, realm.intrinsics.SymbolIterator);
  } // 2. Let iterator be ? Call(method, obj).


  let iterator = (0, _index2.Call)(realm, method, obj); // 3. If Type(iterator) is not Object, throw a TypeError exception.

  if (!(iterator instanceof _index.ObjectValue)) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 4. Return iterator.


  return iterator;
} // ECMA262 7.4.5


function IteratorStep(realm, iterator) {
  // 1. Let result be ? IteratorNext(iterator).
  let result = IteratorNext(realm, iterator); // 2. Let done be ? IteratorComplete(result).

  let done = IteratorComplete(realm, result); // 3. If done is true, return false.

  if (done) return false; // 4. Return result.

  return result;
} // ECMA262 7.4.4


function IteratorValue(realm, iterResult) {
  // 1. Assert: Type(iterResult) is Object.
  (0, _invariant.default)(iterResult instanceof _index.ObjectValue, "expected obj"); // 2. Return ? Get(iterResult, "value").

  return (0, _index2.Get)(realm, iterResult, "value");
} // ECMA262 7.4.2


function IteratorComplete(realm, iterResult) {
  // 1. Assert: Type(iterResult) is Object.
  (0, _invariant.default)(iterResult instanceof _index.ObjectValue, "expected obj"); // 2. Return ToBoolean(? Get(iterResult, "done")).

  return _singletons.To.ToBooleanPartial(realm, (0, _index2.Get)(realm, iterResult, "done"));
} // ECMA262 7.4.2


function IteratorNext(realm, iterator, value) {
  // 1. If value was not passed, then
  let result;

  if (!value) {
    // a. Let result be ? Invoke(iterator, "next", « »).
    result = (0, _index2.Invoke)(realm, iterator, "next", []);
  } else {
    // 2. Else,
    // a. Let result be ? Invoke(iterator, "next", « value »).
    result = (0, _index2.Invoke)(realm, iterator, "next", [value]);
  } // 3. If Type(result) is not Object, throw a TypeError exception.


  if (!(result instanceof _index.ObjectValue)) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 4. Return result.


  return result;
} // ECMA262 7.4.8


function CreateListIterator(realm, list) {
  // 1. Let iterator be ObjectCreate(%IteratorPrototype%, « [[IteratorNext]], [[IteratedList]], [[ListIteratorNextIndex]] »).
  let iterator = _singletons.Create.ObjectCreate(realm, realm.intrinsics.IteratorPrototype, {
    $IteratorNext: undefined,
    $IteratedList: undefined,
    $ListIteratorNextIndex: undefined
  }); // 2. Set iterator's [[IteratedList]] internal slot to list.


  iterator.$IteratedList = list; // 3. Set iterator's [[ListIteratorNextIndex]] internal slot to 0.

  iterator.$ListIteratorNextIndex = 0; // 4. Let next be a new built-in function object as defined in ListIterator next (7.4.8.1).

  let next = ListIterator_next(realm); // 5. Set iterator's [[IteratorNext]] internal slot to next.

  iterator.$IteratorNext = next; // 6. Perform CreateMethodProperty(iterator, "next", next).

  _singletons.Create.CreateMethodProperty(realm, iterator, new _index.StringValue(realm, "next"), next); // 7. Return iterator.


  return iterator;
} // ECMA262 7.4.8.1


function ListIterator_next(realm) {
  let func = new _index.NativeFunctionValue(realm, undefined, "next", 0, context => {
    (0, _invariant.default)(context instanceof _index.ObjectValue); // 1. Let O be the this value.

    let O = context; // 2. Let f be the active function object.

    let f = func; // 3. If O does not have a [[IteratorNext]] internal slot, throw a TypeError exception.

    if (!O.$IteratorNext) {
      throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError, "O does not have an [[IteratorNext]] internal slot");
    } // 4. Let next be the value of the [[IteratorNext]] internal slot of O.


    let next = O.$IteratorNext; // 5. If SameValue(f, next) is false, throw a TypeError exception.

    if (!(0, _abstract.SameValue)(realm, f, next)) {
      throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
    } // 6. If O does not have an [[IteratedList]] internal slot, throw a TypeError exception.


    if (!O.$IteratedList) {
      throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError, "O does not have an [[IteratedList]] internal slot");
    } // 7. Let list be the value of the [[IteratedList]] internal slot of O.


    let list = O.$IteratedList;
    (0, _invariant.default)(typeof O.$ListIteratorNextIndex === "number"); // 8. Let index be the value of the [[ListIteratorNextIndex]] internal slot of O.
    // Default to 0 for Flow.

    let index = O.$ListIteratorNextIndex; // 9. Let len be the number of elements of list.

    let len = list.length; // 10. If index ≥ len, then

    if (index >= len) {
      // a. Return CreateIterResultObject(undefined, true).
      return _singletons.Create.CreateIterResultObject(realm, realm.intrinsics.undefined, true);
    } // 11. Set the value of the [[ListIteratorNextIndex]] internal slot of O to index+1.


    O.$ListIteratorNextIndex = index + 1; // 12. Return CreateIterResultObject(list[index], false).

    return _singletons.Create.CreateIterResultObject(realm, list[index], false);
  });
  return func;
} // ECMA262 23.1.5.1


function CreateMapIterator(realm, map, kind) {
  // 1. If Type(map) is not Object, throw a TypeError exception.
  if (!(map instanceof _index.ObjectValue)) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 2. If map does not have a [[MapData]] internal slot, throw a TypeError exception.


  if (!map.$MapData) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 3. Let iterator be ObjectCreate(%MapIteratorPrototype%, « [[Map]], [[MapNextIndex]], [[MapIterationKind]] »).


  let iterator = _singletons.Create.ObjectCreate(realm, realm.intrinsics.MapIteratorPrototype, {
    $Map: undefined,
    $MapNextIndex: undefined,
    $MapIterationKind: undefined
  }); // 4. Set iterator's [[Map]] internal slot to map.


  iterator.$Map = map; // 5. Set iterator's [[MapNextIndex]] internal slot to 0.

  iterator.$MapNextIndex = new _index.NumberValue(realm, 0); // 6. Set iterator's [[MapIterationKind]] internal slot to kind.

  iterator.$MapIterationKind = kind; // 7. Return iterator.

  return iterator;
} // ECMA262 23.2.5.1


function CreateSetIterator(realm, set, kind) {
  // 1. If Type(set) is not Object, throw a TypeError exception.
  if (!(set instanceof _index.ObjectValue)) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 2. If set does not have a [[SetData]] internal slot, throw a TypeError exception.


  if (!set.$SetData) {
    throw realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 3. Let iterator be ObjectCreate(%SetIteratorPrototype%, « [[IteratedSet]], [[SetNextIndex]], [[SetIterationKind]] »).


  let iterator = _singletons.Create.ObjectCreate(realm, realm.intrinsics.SetIteratorPrototype, {
    $IteratedSet: undefined,
    $SetNextIndex: undefined,
    $SetIterationKind: undefined
  }); // 4. Set iterator's [[IteratedSet]] internal slot to set.


  iterator.$IteratedSet = set; // 5. Set iterator's [[SetNextIndex]] internal slot to 0.

  iterator.$SetNextIndex = 0; // 6. Set iterator's [[SetIterationKind]] internal slot to kind.

  iterator.$SetIterationKind = kind; // 7. Return iterator.

  return iterator;
} // ECMA262 7.4.6


function IteratorClose(realm, iterator, completion) {
  // 1. Assert: Type(iterator) is Object.
  (0, _invariant.default)(iterator instanceof _index.ObjectValue, "expected object"); // 2. Assert: completion is a Completion Record.

  (0, _invariant.default)(completion instanceof _completions.Completion, "expected completion record"); // 3. Let return be ? GetMethod(iterator, "return").

  let ret = (0, _index2.GetMethod)(realm, iterator, "return"); // 4. If return is undefined, return Completion(completion).

  if (ret instanceof _index.UndefinedValue) return completion; // 5. Let innerResult be Call(return, iterator, « »).

  let innerResult;

  try {
    innerResult = (0, _index2.Call)(realm, ret.throwIfNotConcrete(), iterator, []);
  } catch (error) {
    if (error instanceof _completions.AbruptCompletion) {
      innerResult = error;
    } else {
      throw error;
    }
  } // 6. If completion.[[Type]] is throw, return Completion(completion).


  if (completion instanceof _completions.ThrowCompletion) return completion; // 7. If innerResult.[[Type]] is throw, return Completion(innerResult).

  if (innerResult instanceof _completions.ThrowCompletion) return innerResult; // 8. If Type(innerResult.[[Value]]) is not Object, throw a TypeError exception.

  if (!(innerResult instanceof _index.ObjectValue)) {
    return realm.createErrorThrowCompletion(realm.intrinsics.TypeError);
  } // 9. Return Completion(completion).


  return completion;
} // ECMA262 22.2.2.1.1


function IterableToList(realm, items, method) {
  // 1. Let iterator be ? GetIterator(items, method).
  let iterator = GetIterator(realm, items, method); // 2. Let values be a new empty List.

  let values = []; // 3. Let next be true.

  let next = true; // 4. Repeat, while next is not false

  while (next !== false) {
    // a. Let next be ? IteratorStep(iterator).
    next = IteratorStep(realm, iterator); // b. If next is not false, then

    if (next !== false) {
      // i. Let nextValue be ? IteratorValue(next).
      let nextValue = IteratorValue(realm, next); // ii. Append nextValue to the end of the List values.

      values.push(nextValue);
    }
  } // 5. Return values.


  return values;
}
//# sourceMappingURL=iterator.js.map