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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
function IteratorIdentity() {
return this;
}
/* ECMA262 7.2.7 */
function IteratorNext(iteratorRecord, value) {
// Steps 1-2.
var result =
ArgumentsLength() < 2
? callContentFunction(iteratorRecord.nextMethod, iteratorRecord.iterator)
: callContentFunction(
iteratorRecord.nextMethod,
iteratorRecord.iterator,
value
);
// Step 3.
if (!IsObject(result)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, result);
}
// Step 4.
return result;
}
function GetIterator(obj, isAsync, method) {
// Step 1. If hint is not present, set hint to sync.
// Step 2. If method is not present, then
if (!method) {
// Step 2.a. If hint is async, then
if (isAsync) {
// Step 2.a.i. Set method to ? GetMethod(obj, @@asyncIterator).
method = GetMethod(obj, GetBuiltinSymbol("asyncIterator"));
// Step 2.a.ii. If method is undefined, then
if (!method) {
// Step 2.a.ii.1. Let syncMethod be ? GetMethod(obj, @@iterator).
var syncMethod = GetMethod(obj, GetBuiltinSymbol("iterator"));
// Step 2.a.ii.2. Let syncIteratorRecord be ? GetIterator(obj, sync, syncMethod).
var syncIteratorRecord = GetIterator(obj, false, syncMethod);
// Step 2.a.ii.2. Return CreateAsyncFromSyncIterator(syncIteratorRecord).
return CreateAsyncFromSyncIterator(syncIteratorRecord.iterator, syncIteratorRecord.nextMethod);
}
} else {
// Step 2.b. Otherwise, set method to ? GetMethod(obj, @@iterator).
method = GetMethod(obj, GetBuiltinSymbol("iterator"));
}
}
// Step 3. Let iterator be ? Call(method, obj).
var iterator = callContentFunction(method, obj);
// Step 4. If Type(iterator) is not Object, throw a TypeError exception.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_NOT_ITERABLE, obj === null ? "null" : typeof obj);
}
// Step 5. Let nextMethod be ? GetV(iterator, "next").
var nextMethod = iterator.next;
// Step 6. Let iteratorRecord be the Record { [[Iterator]]: iterator, [[NextMethod]]: nextMethod, [[Done]]: false }.
var iteratorRecord = {
__proto__: null,
iterator,
nextMethod,
done: false,
};
// Step 7. Return iteratorRecord.
return iteratorRecord;
}
/**
* GetIteratorFlattenable ( obj, stringHandling )
*
*/
function GetIteratorFlattenable(obj, rejectStrings) {
assert(typeof rejectStrings === "boolean", "rejectStrings is a boolean");
// Step 1.
if (!IsObject(obj)) {
// Step 1.a.
if (rejectStrings || typeof obj !== "string") {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, obj === null ? "null" : typeof obj);
}
}
// Step 2.
var method = obj[GetBuiltinSymbol("iterator")];
// Steps 3-4.
var iterator;
if (IsNullOrUndefined(method)) {
iterator = obj;
} else {
iterator = callContentFunction(method, obj);
}
// Step 5.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 6. (Caller must call GetIteratorDirect.)
return iterator;
}
/**
* Iterator.from ( O )
*
*/
function IteratorFrom(O) {
// Step 1. (Inlined call to GetIteratorDirect.)
var iterator = GetIteratorFlattenable(O, /* rejectStrings= */ false);
var nextMethod = iterator.next;
// Step 2.
//
// Calls |isPrototypeOf| instead of |instanceof| to avoid looking up the
// `@@hasInstance` property.
var hasInstance = callFunction(
std_Object_isPrototypeOf,
GetBuiltinPrototype("Iterator"),
iterator
);
// Step 3.
if (hasInstance) {
return iterator;
}
// Step 4.
var wrapper = NewWrapForValidIterator();
// Step 5.
UnsafeSetReservedSlot(
wrapper,
WRAP_FOR_VALID_ITERATOR_ITERATOR_SLOT,
iterator
);
UnsafeSetReservedSlot(
wrapper,
WRAP_FOR_VALID_ITERATOR_NEXT_METHOD_SLOT,
nextMethod
);
// Step 6.
return wrapper;
}
/**
* %WrapForValidIteratorPrototype%.next ( )
*
*/
function WrapForValidIteratorNext() {
// Steps 1-2.
var O = this;
if (!IsObject(O) || (O = GuardToWrapForValidIterator(O)) === null) {
return callFunction(
CallWrapForValidIteratorMethodIfWrapped,
this,
"WrapForValidIteratorNext"
);
}
// Step 3.
var iterator = UnsafeGetReservedSlot(O, WRAP_FOR_VALID_ITERATOR_ITERATOR_SLOT);
var nextMethod = UnsafeGetReservedSlot(O, WRAP_FOR_VALID_ITERATOR_NEXT_METHOD_SLOT);
// Step 4.
return callContentFunction(nextMethod, iterator);
}
/**
* %WrapForValidIteratorPrototype%.return ( )
*
*/
function WrapForValidIteratorReturn() {
// Steps 1-2.
var O = this;
if (!IsObject(O) || (O = GuardToWrapForValidIterator(O)) === null) {
return callFunction(
CallWrapForValidIteratorMethodIfWrapped,
this,
"WrapForValidIteratorReturn"
);
}
// Step 3.
var iterator = UnsafeGetReservedSlot(O, WRAP_FOR_VALID_ITERATOR_ITERATOR_SLOT);
// Step 4.
assert(IsObject(iterator), "iterator is an object");
// Step 5.
var returnMethod = iterator.return;
// Step 6.
if (IsNullOrUndefined(returnMethod)) {
return {
value: undefined,
done: true,
};
}
// Step 7.
return callContentFunction(returnMethod, iterator);
}
#ifdef ENABLE_EXPLICIT_RESOURCE_MANAGEMENT
/**
* Explicit Resource Management Proposal
* 27.1.2.1 %IteratorPrototype% [ @@dispose ] ( )
*/
function IteratorDispose() {
// Step 1. Let O be the this value.
var O = this;
// Step 2. Let return be ? GetMethod(O, "return").
var returnMethod = GetMethod(O, "return");
// Step 3. If return is not undefined, then
if (returnMethod !== undefined) {
// Step 3.a. Perform ? Call(return, O, « »).
callContentFunction(returnMethod, O);
}
// Step 4. Return NormalCompletion(empty). (implicit)
}
#endif
/**
* %IteratorHelperPrototype%.next ( )
*
*/
function IteratorHelperNext() {
// Step 1.
var O = this;
if (!IsObject(O) || (O = GuardToIteratorHelper(O)) === null) {
return callFunction(
CallIteratorHelperMethodIfWrapped,
this,
"IteratorHelperNext"
);
}
var generator = UnsafeGetReservedSlot(O, ITERATOR_HELPER_GENERATOR_SLOT);
return callFunction(GeneratorNext, generator, undefined);
}
/**
* %IteratorHelperPrototype%.return ( )
*
*/
function IteratorHelperReturn() {
// Step 1.
var O = this;
// Step 2.
if (!IsObject(O) || (O = GuardToIteratorHelper(O)) === null) {
return callFunction(
CallIteratorHelperMethodIfWrapped,
this,
"IteratorHelperReturn"
);
}
// Step 3. (Implicit)
// Steps 4-6.
var generator = UnsafeGetReservedSlot(O, ITERATOR_HELPER_GENERATOR_SLOT);
return callFunction(GeneratorReturn, generator, undefined);
}
// Lazy %Iterator.prototype% methods
//
// In order to match the semantics of the built-in generator objects used in
// the proposal, we use a reserved slot on the IteratorHelper objects to store
// a regular generator that is called from the %IteratorHelper.prototype%
// methods.
//
// Each of the lazy methods is divided into a prelude and a body, with the
// eager prelude steps being contained in the corresponding IteratorX method
// and the lazy body steps inside the IteratorXGenerator generator functions.
//
// Each prelude method initializes and returns a new IteratorHelper object.
// As part of this initialization process, the appropriate generator function
// is called, followed by GeneratorNext being called on returned generator
// instance in order to move it to its first yield point. This is done so that
// if the `return` method is called on the IteratorHelper before `next` has been
// called, we can catch them in the try and use the finally block to close the
// underlying iterator.
/**
* Iterator.prototype.map ( mapper )
*
*/
function IteratorMap(mapper) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(mapper)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, mapper));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 5-7.
var result = NewIteratorHelper();
var generator = IteratorMapGenerator(iterator, nextMethod, mapper);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Stop at the initial yield point.
callFunction(GeneratorNext, generator);
// Step 8.
return result;
}
/**
* Iterator.prototype.map ( mapper )
*
* Abstract closure definition.
*
*/
function* IteratorMapGenerator(iterator, nextMethod, mapper) {
var isReturnCompletion = true;
try {
// Initial yield point to handle closing the iterator before the for-of
// loop has been entered for the first time.
yield;
// Not a Return completion when execution continues normally after |yield|.
isReturnCompletion = false;
} finally {
// Call IteratorClose on a Return completion.
if (isReturnCompletion) {
IteratorClose(iterator);
}
}
// Step 5.a.
var counter = 0;
// Step 5.b.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 5.b.i-iii. (Implicit through for-of loop)
// Step 5.b.iv.
var mapped = callContentFunction(mapper, undefined, value, counter);
// Step 5.b.v. (Implicit through for-of loop)
// Step 5.b.vi.
yield mapped;
// Step 5.b.vii. (Implicit through for-of loop)
// Step 5.b.viii.
counter += 1;
}
}
/**
* Iterator.prototype.filter ( predicate )
*
*/
function IteratorFilter(predicate) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(predicate)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, predicate));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 5-7.
var result = NewIteratorHelper();
var generator = IteratorFilterGenerator(iterator, nextMethod, predicate);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Stop at the initial yield point.
callFunction(GeneratorNext, generator);
// Step 8.
return result;
}
/**
* Iterator.prototype.filter ( predicate )
*
* Abstract closure definition.
*
*/
function* IteratorFilterGenerator(iterator, nextMethod, predicate) {
var isReturnCompletion = true;
try {
// Initial yield point to handle closing the iterator before the for-of
// loop has been entered for the first time.
yield;
// Not a Return completion when execution continues normally after |yield|.
isReturnCompletion = false;
} finally {
// Call IteratorClose on a Return completion.
if (isReturnCompletion) {
IteratorClose(iterator);
}
}
// Step 5.a.
var counter = 0;
// Step 5.b.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 5.b.i-iii. (Implicit through for-of loop)
// Step 5.b.iv.
var selected = callContentFunction(predicate, undefined, value, counter);
// Step 5.b.v. (Implicit through for-of loop)
// Step 5.b.vi.
if (selected) {
// Step 5.b.vi.1.
yield value;
// Step 5.b.vi.2. (Implicit through for-of loop)
}
// Step 5.b.vii.
counter += 1;
}
}
/**
* Iterator.prototype.take ( limit )
*
*/
function IteratorTake(limit) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Steps 3-6.
var integerLimit = std_Math_trunc(limit);
if (!(integerLimit >= 0)) {
ThrowRangeError(JSMSG_NEGATIVE_LIMIT);
}
// Step 7. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 8-10.
var result = NewIteratorHelper();
var generator = IteratorTakeGenerator(iterator, nextMethod, integerLimit);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Stop at the initial yield point.
callFunction(GeneratorNext, generator);
// Step 11.
return result;
}
/**
* Iterator.prototype.take ( limit )
*
* Abstract closure definition.
*
*/
function* IteratorTakeGenerator(iterator, nextMethod, remaining) {
var isReturnCompletion = true;
try {
// Initial yield point to handle closing the iterator before the for-of
// loop has been entered for the first time.
yield;
// Not a Return completion when execution continues normally after |yield|.
isReturnCompletion = false;
} finally {
// Call IteratorClose on a Return completion.
if (isReturnCompletion) {
IteratorClose(iterator);
}
}
// Step 8.a. (Implicit)
// Step 8.b.i. (Reordered before for-of loop entry)
if (remaining === 0) {
IteratorClose(iterator);
return;
}
// Step 8.b.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 8.b.iii-iv. (Implicit through for-of loop)
// Step 8.b.v.
yield value;
// Step 8.b.vi. (Implicit through for-of loop)
// Steps 8.b.i-ii. (Reordered)
if (--remaining === 0) {
// |break| implicitly calls IteratorClose.
break;
}
}
}
/**
* Iterator.prototype.drop ( limit )
*
*/
function IteratorDrop(limit) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Steps 3-6.
var integerLimit = std_Math_trunc(limit);
if (!(integerLimit >= 0)) {
ThrowRangeError(JSMSG_NEGATIVE_LIMIT);
}
// Step 7. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 8-10.
var result = NewIteratorHelper();
var generator = IteratorDropGenerator(iterator, nextMethod, integerLimit);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Stop at the initial yield point.
callFunction(GeneratorNext, generator);
// Step 11.
return result;
}
/**
* Iterator.prototype.drop ( limit )
*
* Abstract closure definition.
*
*/
function* IteratorDropGenerator(iterator, nextMethod, remaining) {
var isReturnCompletion = true;
try {
// Initial yield point to handle closing the iterator before the for-of
// loop has been entered for the first time.
yield;
// Not a Return completion when execution continues normally after |yield|.
isReturnCompletion = false;
} finally {
// Call IteratorClose on a Return completion.
if (isReturnCompletion) {
IteratorClose(iterator);
}
}
// Step 8.a. (Implicit)
// Steps 8.b-c.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Step 8.b.i.
if (remaining-- <= 0) {
// Steps 8.b.ii-iii. (Implicit through for-of loop)
// Steps 8.c.i-ii. (Implicit through for-of loop)
// Step 8.c.iii.
yield value;
// Step 8.c.iv. (Implicit through for-of loop)
}
}
}
/**
* Iterator.prototype.flatMap ( mapper )
*
*/
function IteratorFlatMap(mapper) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(mapper)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, mapper));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 5-7.
var result = NewIteratorHelper();
var generator = IteratorFlatMapGenerator(iterator, nextMethod, mapper);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Stop at the initial yield point.
callFunction(GeneratorNext, generator);
// Step 8.
return result;
}
/**
* Iterator.prototype.flatMap ( mapper )
*
*/
function* IteratorFlatMapGenerator(iterator, nextMethod, mapper) {
var isReturnCompletion = true;
try {
// Initial yield point to handle closing the iterator before the for-of
// loop has been entered for the first time.
yield;
// Not a Return completion when execution continues normally after |yield|.
isReturnCompletion = false;
} finally {
// Call IteratorClose on a Return completion.
if (isReturnCompletion) {
IteratorClose(iterator);
}
}
// Step 5.a.
var counter = 0;
// Step 5.b.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 5.b.i-iii. (Implicit through for-of loop)
// Step 5.b.iv.
var mapped = callContentFunction(mapper, undefined, value, counter);
// Step 5.b.v. (Implicit through for-of loop)
// Steps 5.b.vi.
var innerIterator = GetIteratorFlattenable(mapped, /* rejectStrings= */ true);
var innerIteratorNextMethod = innerIterator.next;
// Step 5.b.vii. (Implicit through for-of loop)
// Steps 5.b.viii-ix.
for (var innerValue of allowContentIterWithNext(innerIterator, innerIteratorNextMethod)) {
// Steps 5.b.ix.1-3 and 5.b.ix.4.a-b. (Implicit through for-of loop)
// Step 5.b.ix.4.c.
yield innerValue;
// Step 5.b.ix.4.d. (Implicit through for-of loop)
}
// Step 5.b.x.
counter += 1;
}
}
/**
* Iterator.prototype.reduce ( reducer [ , initialValue ] )
*
*/
function IteratorReduce(reducer /*, initialValue*/) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(reducer)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, reducer));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 5-6.
var accumulator;
var counter;
if (ArgumentsLength() === 1) {
// Steps 5.a-d. (Moved below.)
counter = -1;
} else {
// Step 6.a.
accumulator = GetArgument(1);
// Step 6.b.
counter = 0;
}
// Step 7.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
if (counter < 0) {
// Step 5. (Reordered steps to compute initial accumulator.)
// Step 5.c.
accumulator = value;
// Step 5.d.
counter = 1;
} else {
// Steps 7.a-c and 7.e. (Implicit through for-of loop)
// Steps 7.d and 7.f-g.
accumulator = callContentFunction(reducer, undefined, accumulator, value, counter++);
}
}
// Step 5.b.
if (counter < 0) {
ThrowTypeError(JSMSG_EMPTY_ITERATOR_REDUCE);
}
// Step 7.b.
return accumulator;
}
/**
* Iterator.prototype.toArray ( )
*
*/
function IteratorToArray() {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Steps 4-5.
return [...allowContentIterWithNext(iterator, nextMethod)];
}
/**
* Iterator.prototype.forEach ( fn )
*
*/
function IteratorForEach(fn) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(fn)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, fn));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Step 5.
var counter = 0;
// Step 6.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 6.a-c. (Implicit through for-of loop)
// Steps 6.d and 6.f.
callContentFunction(fn, undefined, value, counter++);
// Step 6.e. (Implicit through for-of loop)
}
}
/**
* Iterator.prototype.some ( predicate )
*
*/
function IteratorSome(predicate) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(predicate)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, predicate));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Step 5.
var counter = 0;
// Step 6.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 6.a-c. (Implicit through for-of loop)
// Steps 6.d-g.
if (callContentFunction(predicate, undefined, value, counter++)) {
return true;
}
}
// Step 6.b.
return false;
}
/**
* Iterator.prototype.every ( predicate )
*
*/
function IteratorEvery(predicate) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(predicate)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, predicate));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Step 5.
var counter = 0;
// Step 6.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 6.a-c. (Implicit through for-of loop)
// Steps 6.d-g.
if (!callContentFunction(predicate, undefined, value, counter++)) {
return false;
}
}
// Step 6.b.
return true;
}
/**
* Iterator.prototype.find ( predicate )
*
*/
function IteratorFind(predicate) {
// Step 1.
var iterator = this;
// Step 2.
if (!IsObject(iterator)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, iterator === null ? "null" : typeof iterator);
}
// Step 3.
if (!IsCallable(predicate)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, predicate));
}
// Step 4. (Inlined call to GetIteratorDirect.)
var nextMethod = iterator.next;
// Step 5.
var counter = 0;
// Step 6.
for (var value of allowContentIterWithNext(iterator, nextMethod)) {
// Steps 6.a-c. (Implicit through for-of loop)
// Steps 6.d-g.
if (callContentFunction(predicate, undefined, value, counter++)) {
return value;
}
}
}
#ifdef NIGHTLY_BUILD
/**
* Iterator.concat ( ...items )
*
*/
function IteratorConcat() {
// Step 1.
//
// Stored in reversed order to simplify removing processed items.
var index = ArgumentsLength() * 2;
var iterables = std_Array(index);
// Step 2.
for (var i = 0; i < ArgumentsLength(); i++) {
var item = GetArgument(i);
// Step 2.a.
if (!IsObject(item)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, typeof item);
}
// Step 2.b. (Inlined GetMethod)
var method = item[GetBuiltinSymbol("iterator")];
// Step 2.c.
if (!IsCallable(method)) {
ThrowTypeError(JSMSG_NOT_ITERABLE, ToSource(item));
}
// Step 2.d.
DefineDataProperty(iterables, --index, item);
DefineDataProperty(iterables, --index, method);
}
assert(index === 0, "all items stored");
// Steps 3-5.
var result = NewIteratorHelper();
var generator = IteratorConcatGenerator(iterables);
UnsafeSetReservedSlot(
result,
ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
// Step 6.
return result;
}
/**
* Iterator.concat ( ...items )
*
*/
function* IteratorConcatGenerator(iterables) {
assert(IsArray(iterables), "iterables is an array");
assert(iterables.length % 2 === 0, "iterables contains pairs (item, method)");
// Step 3.a.
for (var i = iterables.length; i > 0;) {
var item = iterables[--i];
var method = iterables[--i];
// Remove processed items to avoid keeping them alive.
iterables.length -= 2;
// Steps 3.a.i-v.
for (var innerValue of allowContentIterWith(item, method)) {
// Steps 3.a.v.1-3. (Implicit through for-of loop)
yield innerValue;
}
}
}
/**
* Iterator.zip (iterables [, options])
*
*/
function IteratorZip(predicate) {
return false;
}
/**
* Iterator.zipKeyed ( iterables [, options] )
*
*/
function IteratorZipKeyed(predicate) {
return false;
}
/**
* CreateNumericRangeIterator (start, end, optionOrStep, type)
* Step 18
*
*/
function IteratorRangeNext() {
var obj = this;
// Step 18. Let closure be a new Abstract Closure with no parameters
// that captures start, end, step, inclusiveEnd, zero, one and performs the following steps when called:
if (!IsObject(obj) || (obj = GuardToIteratorRange(obj)) === null) {
return callFunction(
CallIteratorRangeMethodIfWrapped,
this,
"IteratorRangeNext"
);
}
// Retrieve values from reserved slots
var start = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_START);
var end = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_END);
var step = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_STEP);
var inclusiveEnd = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_INCLUSIVE_END);
var zero = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_ZERO);
var one = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_ONE);
var currentCount = UnsafeGetReservedSlot(obj, ITERATOR_RANGE_SLOT_CURRENT_COUNT);
// Step 18.a: If end > start, let ifIncrease be true
// Step 18.b: Else let ifIncrease be false
var ifIncrease = end > start;
// Step 18.c: If step > zero, let ifStepIncrease be true
// Step 18.d: Else let ifStepIncrease be false
var ifStepIncrease = step > zero;
// Step 18.e: If ifIncrease is not ifStepIncrease, return undefined.
if (ifIncrease !== ifStepIncrease) {
return { value: undefined, done: true };
}
// Step 18.f: Let hitsEnd be false
var hitsEnd = false;
// Step 18.g: Let currentCount be zero (already handled via slots)
// Step 18.i.i: Let currentYieldingValue be start + (step × currentCount)
var currentYieldingValue = start + (step * currentCount);
// Step 18.i.ii: If currentYieldingValue is equal to end, set hitsEnd to true
hitsEnd = currentYieldingValue === end && !inclusiveEnd;
// Step 18.i.iii: Set currentCount to currentCount + one
currentCount = currentCount + one;
// Step 18.i.iv: If ifIncrease is true, then
if (ifIncrease) {
// Step 18.i.iv.1: If inclusiveEnd is true, then
if (inclusiveEnd) {
// Step 18.i.iv.1.a: If currentYieldingValue > end, return undefined.
if (currentYieldingValue > end) {
return { value: undefined, done: true };
}
} else {
// Step 18.i.iv.2: If currentYieldingValue >= end, return undefined
if (currentYieldingValue >= end) {
return { value: undefined, done: true };
}
}
} else {
// Step 18.i.v: Else
// Step 18.i.v.1: If inclusiveEnd is true, then
if (inclusiveEnd) {
//Step 18.i.v.1.a.a. If end > currentYieldingValue, return undefined.
if (end > currentYieldingValue) {
return { value: undefined, done: true };
}
} else {
// Step 18.i.v.2: Else
if (end >= currentYieldingValue) {
// Step 18i.v.2.a: If end >= currentYieldingValue, return undefined
return { value: undefined, done: true };
}
}
}
// Step 18.i.vi: Yield currentYieldingValue
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_CURRENT_COUNT, currentCount);
// Step 18.j: Return undefined if the loop completes
if (hitsEnd) {
return { value: undefined, done: true };
}
// Return the current value
return { value: currentYieldingValue, done: false };
}
/**
* CreateNumericRangeIterator (start, end, optionOrStep, type)
*
*/
function CreateNumericRangeIterator(start, end, optionOrStep, isNumberRange) {
// Step 1: If start is NaN, throw a RangeError exception.
if (isNumberRange && Number_isNaN(start)) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_INVALID_START_RANGEERR);
}
// Step 2: If end is NaN, throw a RangeError exception.
if (isNumberRange && Number_isNaN(end)) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_INVALID_END_RANGEERR);
}
// Step 3: If type is NUMBER-RANGE, then
if (isNumberRange) {
// Step 3.a. Assert: start is a Number.
assert(typeof start === 'number', "The 'start' argument must be a number");
// Step 3.b. If end is not a Number, throw a TypeError exception.
if (typeof end !== 'number') {
ThrowTypeError(JSMSG_ITERATOR_RANGE_INVALID_END);
}
// Step 3.c. Let zero be 0ℤ.
var zero = 0;
// Step 3.d. Let one be 1ℤ.
var one = 1;
// 4: Else,
} else {
// 4.a. Assert: start is a BigInt.
assert(typeof start === 'bigint', "The 'start' argument must be a bigint");
// 4.b. If end is not +∞𝔽 or -∞𝔽 and end is not a BigInt, throw a TypeError exception.
if (typeof end !== 'bigint' && !(Number_isFinite(end))) {
ThrowTypeError(JSMSG_ITERATOR_RANGE_INVALID_END);
}
// 4.c. Let zero be 0𝔽.
var zero = 0n;
// 4.d. Let one be 1𝔽.
var one = 1n;
}
// Step 5: If start is +∞ or -∞, throw a RangeError exception.
if (typeof start === 'number' && !Number_isFinite(start)) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_START_INFINITY);
}
// Step 6: Let inclusiveEnd be false.
var inclusiveEnd = false;
// Step 7: If optionOrStep is undefined or null, then
// Step 7.a. Let step be undefined.
var step;
// Step 8: Else if optionOrStep is an Object, then
if (optionOrStep !== null && typeof optionOrStep === 'object') {
// Step 8.a. Let step be ? Get(optionOrStep, "step").
step = optionOrStep.step;
// Step 8.b. Set inclusiveEnd to ToBoolean(? Get(optionOrStep, "inclusive")).
inclusiveEnd = ToBoolean(optionOrStep.inclusiveEnd);
}
// Step 9: Else if type is NUMBER-RANGE and optionOrStep is a Number, then
else if (isNumberRange && typeof optionOrStep === 'number') {
// Step 9.a. Let step be optionOrStep.
step = optionOrStep;
}
// Step 10: Else if type is BIGINT-RANGE and optionOrStep is a BigInt, then
// Step 10.a. Let step be optionOrStep.
else if (!isNumberRange && typeof optionOrStep === 'bigint') {
step = optionOrStep;
}
// Step 11: Else, throw a TypeError exception.
else if (optionOrStep !== undefined && optionOrStep !== null) {
ThrowTypeError(JSMSG_ITERATOR_RANGE_INVALID_STEP);
}
// Step 12: If step is undefined or null, then
if (step === undefined || step === null) {
// Step 12.a. If end > start, let step be one.
// Step 12.b. Else let step be -one.
step = end > start ? one : -one;
}
// Step 13: If step is NaN, throw a RangeError exception.
if (typeof step === "number" && Number_isNaN(step)) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_STEP_NAN);
}
// Step 14: If type is NUMBER-RANGE and step is not a Number, throw a TypeError exception.
if (isNumberRange && typeof step !== 'number') {
ThrowTypeError(JSMSG_ITERATOR_RANGE_STEP_NOT_NUMBER);
}
// Step 15: Else if type is BIGINT-RANGE and step is not a BigInt, throw a TypeError exception
else if (!isNumberRange && typeof step !== 'bigint') {
ThrowTypeError(JSMSG_ITERATOR_RANGE_STEP_NOT_BIGINT);
}
// Step 16: If step is +∞ or -∞, throw a RangeError exception.
if (typeof step === 'number' && !Number_isFinite(step)) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_STEP_NOT_FINITE);
}
// Step 17: If step is zero and start is not end, throw a RangeError exception.
if (step === zero && start !== end) {
ThrowRangeError(JSMSG_ITERATOR_RANGE_STEP_ZERO);
}
// Step 19: Return CreateIteratorFromClosure(closure, "%NumericRangeIteratorPrototype%", %NumericRangeIteratorPrototype%).
var obj = NewIteratorRange();
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_START, start);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_END, end);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_STEP, step);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_INCLUSIVE_END, inclusiveEnd);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_ZERO, zero);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_ONE, one);
UnsafeSetReservedSlot(obj, ITERATOR_RANGE_SLOT_CURRENT_COUNT, zero);
return obj;
}
/**
* Iterator.range ( start, end, optionOrStep )
*
*/
function IteratorRange(start, end, optionOrStep) {
// Step 1. If start is a Number, return ? CreateNumericRangeIterator(start, end, optionOrStep, NUMBER-RANGE)
if (typeof start === 'number') {
return CreateNumericRangeIterator(start, end, optionOrStep, true);
}
// Step 2. If start is a BigInt, return ? CreateNumericRangeIterator(start, end, optionOrStep, BIGINT-RANGE)
if (typeof start === 'bigint') {
return CreateNumericRangeIterator(start, end, optionOrStep, false);
}
// Step 3. Throw a TypeError exception.
ThrowTypeError(JSMSG_ITERATOR_RANGE_INVALID_START);
}
#endif