Source code
Revision control
Copy as Markdown
Other Tools
/* 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 AsyncIteratorIdentity() {
return this;
}
function AsyncGeneratorNext(val) {
assert(
IsAsyncGeneratorObject(this),
"ThisArgument must be a generator object for async generators"
);
return resumeGenerator(this, val, "next");
}
function AsyncGeneratorThrow(val) {
assert(
IsAsyncGeneratorObject(this),
"ThisArgument must be a generator object for async generators"
);
return resumeGenerator(this, val, "throw");
}
function AsyncGeneratorReturn(val) {
assert(
IsAsyncGeneratorObject(this),
"ThisArgument must be a generator object for async generators"
);
return resumeGenerator(this, val, "return");
}
/* ECMA262 7.4.7 AsyncIteratorClose */
async function AsyncIteratorClose(iteratorRecord, value) {
// Step 3.
var iterator = iteratorRecord.iterator;
// Step 4.
var returnMethod = iterator.return;
// Step 5.
if (!IsNullOrUndefined(returnMethod)) {
var result = await callContentFunction(returnMethod, iterator);
// Step 8.
if (!IsObject(result)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, DecompileArg(0, result));
}
}
// Step 5b & 9.
return value;
}
/* Iterator Helpers proposal 1.1.1 */
function GetIteratorDirect(obj) {
// Step 1.
if (!IsObject(obj)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, DecompileArg(0, obj));
}
// Step 2.
var nextMethod = obj.next;
// Step 3.
if (!IsCallable(nextMethod)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, nextMethod));
}
// Steps 4-5.
return {
iterator: obj,
nextMethod,
done: false,
};
}
/* Iterator Helpers proposal 1.1.1 */
function GetAsyncIteratorDirectWrapper(obj) {
// Step 1.
if (!IsObject(obj)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, obj);
}
// Step 2.
var nextMethod = obj.next;
// Step 3.
if (!IsCallable(nextMethod)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, nextMethod);
}
// Steps 4-5.
return {
// Use a named function expression instead of a method definition, so
// we don't create an inferred name for this function at runtime.
[GetBuiltinSymbol("asyncIterator")]: function AsyncIteratorMethod() {
return this;
},
next(value) {
return callContentFunction(nextMethod, obj, value);
},
async return(value) {
var returnMethod = obj.return;
if (!IsNullOrUndefined(returnMethod)) {
return callContentFunction(returnMethod, obj, value);
}
return { done: true, value };
},
};
}
/* AsyncIteratorHelper object prototype methods. */
function AsyncIteratorHelperNext(value) {
var O = this;
if (!IsObject(O) || (O = GuardToAsyncIteratorHelper(O)) === null) {
return callFunction(
CallAsyncIteratorHelperMethodIfWrapped,
this,
value,
"AsyncIteratorHelperNext"
);
}
var generator = UnsafeGetReservedSlot(
O,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT
);
return callFunction(IntrinsicAsyncGeneratorNext, generator, value);
}
function AsyncIteratorHelperReturn(value) {
var O = this;
if (!IsObject(O) || (O = GuardToAsyncIteratorHelper(O)) === null) {
return callFunction(
CallAsyncIteratorHelperMethodIfWrapped,
this,
value,
"AsyncIteratorHelperReturn"
);
}
var generator = UnsafeGetReservedSlot(
O,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT
);
return callFunction(IntrinsicAsyncGeneratorReturn, generator, value);
}
function AsyncIteratorHelperThrow(value) {
var O = this;
if (!IsObject(O) || (O = GuardToAsyncIteratorHelper(O)) === null) {
return callFunction(
CallAsyncIteratorHelperMethodIfWrapped,
this,
value,
"AsyncIteratorHelperThrow"
);
}
var generator = UnsafeGetReservedSlot(
O,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT
);
return callFunction(IntrinsicAsyncGeneratorThrow, generator, value);
}
// AsyncIterator lazy Iterator Helper methods
// Iterator Helpers proposal 2.1.6.2-2.1.6.7
//
// The AsyncIterator lazy methods are structured closely to how the Iterator
// lazy methods are. See builtin/Iterator.js for the reasoning.
/* Iterator Helpers proposal 2.1.6.2 Prelude */
function AsyncIteratorMap(mapper) {
// Step 1.
var iterated = GetIteratorDirect(this);
// Step 2.
if (!IsCallable(mapper)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, mapper));
}
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorMapGenerator(iterated, mapper);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.2 Body */
async function* AsyncIteratorMapGenerator(iterated, mapper) {
// Step 1.
var lastValue;
// Step 2.
var needClose = true;
try {
yield;
needClose = false;
for (
var next = await IteratorNext(iterated, lastValue);
!next.done;
next = await IteratorNext(iterated, lastValue)
) {
// Step c.
var value = next.value;
// Steps d-i.
needClose = true;
lastValue = yield callContentFunction(mapper, undefined, value);
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated);
}
}
}
/* Iterator Helpers proposal 2.1.6.3 Prelude */
function AsyncIteratorFilter(filterer) {
// Step 1.
var iterated = GetIteratorDirect(this);
// Step 2.
if (!IsCallable(filterer)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, filterer));
}
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorFilterGenerator(iterated, filterer);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.3 Body */
async function* AsyncIteratorFilterGenerator(iterated, filterer) {
// Step 1.
var lastValue;
// Step 2.
var needClose = true;
try {
yield;
needClose = false;
for (
var next = await IteratorNext(iterated, lastValue);
!next.done;
next = await IteratorNext(iterated, lastValue)
) {
// Step c.
var value = next.value;
// Steps d-h.
needClose = true;
if (await callContentFunction(filterer, undefined, value)) {
lastValue = yield value;
}
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated);
}
}
}
/* Iterator Helpers proposal 2.1.6.4 Prelude */
function AsyncIteratorTake(limit) {
// Step 1.
var iterated = GetIteratorDirect(this);
// Step 2.
var remaining = ToInteger(limit);
// Step 3.
if (remaining < 0) {
ThrowRangeError(JSMSG_NEGATIVE_LIMIT);
}
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorTakeGenerator(iterated, remaining);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.4 Body */
async function* AsyncIteratorTakeGenerator(iterated, remaining) {
// Step 1.
var lastValue;
// Step 2.
var needClose = true;
try {
yield;
needClose = false;
for (; remaining > 0; remaining--) {
var next = await IteratorNext(iterated, lastValue);
if (next.done) {
return undefined;
}
var value = next.value;
needClose = true;
lastValue = yield value;
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated, undefined);
}
}
return AsyncIteratorClose(iterated, undefined);
}
/* Iterator Helpers proposal 2.1.6.5 Prelude */
function AsyncIteratorDrop(limit) {
// Step 1.
var iterated = GetIteratorDirect(this);
// Step 2.
var remaining = ToInteger(limit);
// Step 3.
if (remaining < 0) {
ThrowRangeError(JSMSG_NEGATIVE_LIMIT);
}
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorDropGenerator(iterated, remaining);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.5 Body */
async function* AsyncIteratorDropGenerator(iterated, remaining) {
var needClose = true;
try {
yield;
needClose = false;
// Step 1.
for (; remaining > 0; remaining--) {
var next = await IteratorNext(iterated);
if (next.done) {
return;
}
}
// Step 2.
var lastValue;
// Step 3.
for (
var next = await IteratorNext(iterated, lastValue);
!next.done;
next = await IteratorNext(iterated, lastValue)
) {
// Steps c-d.
var value = next.value;
needClose = true;
lastValue = yield value;
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated);
}
}
}
/* Iterator Helpers proposal 2.1.6.6 Prelude */
function AsyncIteratorAsIndexedPairs() {
// Step 1.
var iterated = GetIteratorDirect(this);
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorAsIndexedPairsGenerator(iterated);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.6 Body */
async function* AsyncIteratorAsIndexedPairsGenerator(iterated) {
var needClose = true;
try {
yield;
needClose = false;
// Step 2.
var lastValue;
// Step 3.
for (
var next = await IteratorNext(iterated, lastValue), index = 0;
!next.done;
next = await IteratorNext(iterated, lastValue), index++
) {
// Steps c-g.
var value = next.value;
needClose = true;
lastValue = yield [index, value];
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated);
}
}
}
/* Iterator Helpers proposal 2.1.6.7 Prelude */
function AsyncIteratorFlatMap(mapper) {
// Step 1.
var iterated = GetIteratorDirect(this);
// Step 2.
if (!IsCallable(mapper)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, mapper));
}
var iteratorHelper = NewAsyncIteratorHelper();
var generator = AsyncIteratorFlatMapGenerator(iterated, mapper);
callFunction(IntrinsicAsyncGeneratorNext, generator);
UnsafeSetReservedSlot(
iteratorHelper,
ASYNC_ITERATOR_HELPER_GENERATOR_SLOT,
generator
);
return iteratorHelper;
}
/* Iterator Helpers proposal 2.1.6.7 Body */
async function* AsyncIteratorFlatMapGenerator(iterated, mapper) {
var needClose = true;
try {
yield;
needClose = false;
// Step 1.
for (
var next = await IteratorNext(iterated);
!next.done;
next = await IteratorNext(iterated)
) {
// Step c.
var value = next.value;
needClose = true;
// Step d.
var mapped = await callContentFunction(mapper, undefined, value);
// Steps f-k.
for await (var innerValue of allowContentIter(mapped)) {
yield innerValue;
}
needClose = false;
}
} finally {
if (needClose) {
AsyncIteratorClose(iterated);
}
}
}
/* Iterator Helpers proposal 2.1.6.8 */
async function AsyncIteratorReduce(reducer /*, initialValue*/) {
// Step 1.
var iterated = GetAsyncIteratorDirectWrapper(this);
// Step 2.
if (!IsCallable(reducer)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, reducer));
}
// Step 3.
var accumulator;
if (ArgumentsLength() === 1) {
// Step a.
var next = await callContentFunction(iterated.next, iterated);
if (!IsObject(next)) {
ThrowTypeError(JSMSG_OBJECT_REQUIRED, DecompileArg(0, next));
}
// Step b.
if (next.done) {
ThrowTypeError(JSMSG_EMPTY_ITERATOR_REDUCE);
}
// Step c.
accumulator = next.value;
} else {
// Step 4.
accumulator = GetArgument(1);
}
// Step 5.
for await (var value of allowContentIter(iterated)) {
// Steps d-h.
accumulator = await callContentFunction(
reducer,
undefined,
accumulator,
value
);
}
// Step 5b.
return accumulator;
}
/* Iterator Helpers proposal 2.1.6.9 */
async function AsyncIteratorToArray() {
// Step 1.
var iterated = { [GetBuiltinSymbol("asyncIterator")]: () => this };
// Step 2.
var items = [];
var index = 0;
// Step 3.
for await (var value of allowContentIter(iterated)) {
// Step d.
DefineDataProperty(items, index++, value);
}
// Step 3b.
return items;
}
/* Iterator Helpers proposal 2.1.6.10 */
async function AsyncIteratorForEach(fn) {
// Step 1.
var iterated = GetAsyncIteratorDirectWrapper(this);
// Step 2.
if (!IsCallable(fn)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, fn));
}
// Step 3.
for await (var value of allowContentIter(iterated)) {
// Steps d-g.
await callContentFunction(fn, undefined, value);
}
}
/* Iterator Helpers proposal 2.1.6.11 */
async function AsyncIteratorSome(fn) {
// Step 1.
var iterated = GetAsyncIteratorDirectWrapper(this);
// Step 2.
if (!IsCallable(fn)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, fn));
}
// Step 3.
for await (var value of allowContentIter(iterated)) {
// Steps d-h.
if (await callContentFunction(fn, undefined, value)) {
return true;
}
}
// Step 3b.
return false;
}
/* Iterator Helpers proposal 2.1.6.12 */
async function AsyncIteratorEvery(fn) {
// Step 1.
var iterated = GetAsyncIteratorDirectWrapper(this);
// Step 2.
if (!IsCallable(fn)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, fn));
}
// Step 3.
for await (var value of allowContentIter(iterated)) {
// Steps d-h.
if (!(await callContentFunction(fn, undefined, value))) {
return false;
}
}
// Step 3b.
return true;
}
/* Iterator Helpers proposal 2.1.6.13 */
async function AsyncIteratorFind(fn) {
// Step 1.
var iterated = GetAsyncIteratorDirectWrapper(this);
// Step 2.
if (!IsCallable(fn)) {
ThrowTypeError(JSMSG_NOT_FUNCTION, DecompileArg(0, fn));
}
// Step 3.
for await (var value of allowContentIter(iterated)) {
// Steps d-h.
if (await callContentFunction(fn, undefined, value)) {
return value;
}
}
}