Var JavascriptStringIterator::EntryNext(RecyclableObject* function, CallInfo callInfo, ...)
{
PROBE_STACK(function->GetScriptContext(), Js::Constants::MinStackDefault);
ARGUMENTS(args, callInfo);
ScriptContext* scriptContext = function->GetScriptContext();
JavascriptLibrary* library = scriptContext->GetLibrary();
Assert(!(callInfo.Flags & CallFlags_New));
Var thisObj = args[0];
if (!JavascriptStringIterator::Is(thisObj))
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_This_NeedStringIterator, L"String Iterator.prototype.next");
}
JavascriptStringIterator* iterator = JavascriptStringIterator::FromVar(thisObj);
JavascriptString* string = iterator->m_string;
if (string == nullptr)
{
return library->CreateIteratorResultObjectUndefinedTrue();
}
charcount_t length = string->GetLength();
charcount_t index = iterator->m_nextIndex;
if (index >= length)
{
// Nulling out the m_string field is important so that the iterator
// does not keep the string alive after iteration is completed.
iterator->m_string = nullptr;
return library->CreateIteratorResultObjectUndefinedTrue();
}
wchar_t chFirst = string->GetItem(index);
Var result;
if (index + 1 == string->GetLength() ||
!NumberUtilities::IsSurrogateLowerPart(chFirst) ||
!NumberUtilities::IsSurrogateUpperPart(string->GetItem(index + 1)))
{
result = scriptContext->GetLibrary()->GetCharStringCache().GetStringForChar(chFirst);
iterator->m_nextIndex += 1;
}
else
{
result = JavascriptString::SubstringCore(string, index, 2, scriptContext);
iterator->m_nextIndex += 2;
}
return library->CreateIteratorResultObjectValueFalse(result);
}
Var JavascriptMapIterator::EntryNext(RecyclableObject* function, CallInfo callInfo, ...)
{
PROBE_STACK(function->GetScriptContext(), Js::Constants::MinStackDefault);
ARGUMENTS(args, callInfo);
ScriptContext* scriptContext = function->GetScriptContext();
JavascriptLibrary* library = scriptContext->GetLibrary();
Assert(!(callInfo.Flags & CallFlags_New));
Var thisObj = args[0];
if (!JavascriptMapIterator::Is(thisObj))
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_This_NeedMapIterator, L"Map Iterator.prototype.next");
}
JavascriptMapIterator* iterator = JavascriptMapIterator::FromVar(thisObj);
JavascriptMap* map = iterator->m_map;
auto& mapIterator = iterator->m_mapIterator;
if (map == nullptr || !mapIterator.Next())
{
iterator->m_map = nullptr;
return library->CreateIteratorResultObjectUndefinedTrue();
}
auto entry = mapIterator.Current();
Var result;
if (iterator->m_kind == JavascriptMapIteratorKind::KeyAndValue)
{
JavascriptArray* keyValueTuple = library->CreateArray(2);
keyValueTuple->SetItem(0, entry.Key(), PropertyOperation_None);
keyValueTuple->SetItem(1, entry.Value(), PropertyOperation_None);
result = keyValueTuple;
}
else if (iterator->m_kind == JavascriptMapIteratorKind::Key)
{
result = entry.Key();
}
else
{
Assert(iterator->m_kind == JavascriptMapIteratorKind::Value);
result = entry.Value();
}
return library->CreateIteratorResultObjectValueFalse(result);
}
Var JavascriptArrayIterator::EntryNext(RecyclableObject* function, CallInfo callInfo, ...)
{
PROBE_STACK(function->GetScriptContext(), Js::Constants::MinStackDefault);
ARGUMENTS(args, callInfo);
ScriptContext* scriptContext = function->GetScriptContext();
JavascriptLibrary* library = scriptContext->GetLibrary();
Assert(!(callInfo.Flags & CallFlags_New));
Var thisObj = args[0];
if (!JavascriptArrayIterator::Is(thisObj))
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_This_NeedArrayIterator, _u("Array Iterator.prototype.next"));
}
JavascriptArrayIterator* iterator = JavascriptArrayIterator::FromVar(thisObj);
Var iterable = iterator->m_iterableObject;
if (iterable == nullptr)
{
return library->CreateIteratorResultObjectUndefinedTrue();
}
int64 length;
bool bArray = false;
JavascriptArray* pArr = nullptr;
if (DynamicObject::IsAnyArray(iterable) && !JavascriptArray::FromAnyArray(iterable)->IsCrossSiteObject())
{
#if ENABLE_COPYONACCESS_ARRAY
JavascriptLibrary::CheckAndConvertCopyOnAccessNativeIntArray<Var>(iterable);
#endif
pArr = JavascriptArray::FromAnyArray(iterable);
length = pArr->GetLength();
bArray = true;
}
else
{
length = JavascriptConversion::ToLength(JavascriptOperators::OP_GetLength(iterable, scriptContext), scriptContext);
}
int64 index = iterator->m_nextIndex;
if (index >= length)
{
// Nulling out the m_iterableObject field is important so that the iterator
// does not keep the iterable object alive after iteration is completed.
iterator->m_iterableObject = nullptr;
return library->CreateIteratorResultObjectUndefinedTrue();
}
iterator->m_nextIndex += 1;
if (iterator->m_kind == JavascriptArrayIteratorKind::Key)
{
return library->CreateIteratorResultObjectValueFalse(JavascriptNumber::ToVar(index, scriptContext));
}
Var value;
if (index <= UINT_MAX)
{
if (bArray)
{
if (JavascriptArray::Is(pArr))
{
value = pArr->DirectGetItem((uint32)index);
}
else
{
if (!JavascriptOperators::GetOwnItem(pArr, (uint32) index, &value, scriptContext))
{
value = library->GetUndefined();
}
}
}
else
{
value = JavascriptOperators::OP_GetElementI_UInt32(iterable, (uint32)index, scriptContext);
}
}
else
{
value = JavascriptOperators::OP_GetElementI(iterable, JavascriptNumber::ToVar(index, scriptContext), scriptContext);
}
if (iterator->m_kind == JavascriptArrayIteratorKind::Value)
{
return library->CreateIteratorResultObjectValueFalse(value);
}
Assert(iterator->m_kind == JavascriptArrayIteratorKind::KeyAndValue);
JavascriptArray* keyValueTuple = library->CreateArray(2);
keyValueTuple->SetItem(0, JavascriptNumber::ToVar(index, scriptContext), PropertyOperation_None);
keyValueTuple->SetItem(1, value, PropertyOperation_None);
return library->CreateIteratorResultObjectValueFalse(keyValueTuple);
}
Var JavascriptGenerator::CallGenerator(ResumeYieldData* yieldData, const wchar_t* apiNameForErrorMessage)
{
ScriptContext* scriptContext = this->GetScriptContext();
JavascriptLibrary* library = scriptContext->GetLibrary();
Var result = nullptr;
if (this->IsExecuting())
{
JavascriptError::ThrowTypeError(scriptContext, JSERR_GeneratorAlreadyExecuting, apiNameForErrorMessage);
}
{
// RAII helper to set the state of the generator to completed if an exception is thrown
// or if the save state InterpreterStackFrame is never created implying the generator
// is JITed and returned without ever yielding.
class GeneratorStateHelper
{
JavascriptGenerator* g;
bool didThrow;
public:
GeneratorStateHelper(JavascriptGenerator* g) : g(g), didThrow(true) { g->SetState(GeneratorState::Executing); }
~GeneratorStateHelper() { g->SetState(didThrow || g->frame == nullptr ? GeneratorState::Completed : GeneratorState::Suspended); }
void DidNotThrow() { didThrow = false; }
} helper(this);
Var thunkArgs[] = { this, yieldData };
Arguments arguments(_countof(thunkArgs), thunkArgs);
try
{
result = JavascriptFunction::CallFunction<1>(this->scriptFunction, this->scriptFunction->GetEntryPoint(), arguments);
helper.DidNotThrow();
}
catch (Js::JavascriptExceptionObject* exceptionObj)
{
if (!exceptionObj->IsGeneratorReturnException())
{
throw exceptionObj;
}
result = exceptionObj->GetThrownObject(nullptr);
}
}
if (this->IsCompleted())
{
result = library->CreateIteratorResultObject(result, library->GetTrue());
}
else
{
int nextOffset = this->frame->GetReader()->GetCurrentOffset();
int endOffset = this->frame->GetFunctionBody()->GetByteCode()->GetLength();
if (nextOffset != endOffset - 1)
{
result = library->CreateIteratorResultObjectValueFalse(result);
}
else
{
result = library->CreateIteratorResultObject(result, library->GetTrue());
this->SetState(GeneratorState::Completed);
}
}
return result;
}