internal readonly TypeSymbol IteratorElementType; // only for async-iterators
public AsyncStateMachine(VariableSlotAllocator variableAllocatorOpt, TypeCompilationState compilationState, MethodSymbol asyncMethod, int asyncMethodOrdinal, TypeKind typeKind)
: base(variableAllocatorOpt, compilationState, asyncMethod, asyncMethodOrdinal)
{
_typeKind = typeKind;
CSharpCompilation compilation = asyncMethod.DeclaringCompilation;
var interfaces = ArrayBuilder <NamedTypeSymbol> .GetInstance();
bool isIterator = asyncMethod.IsIterator;
if (isIterator)
{
var elementType = TypeMap.SubstituteType(asyncMethod.IteratorElementType).TypeSymbol;
this.IteratorElementType = elementType;
bool isEnumerable = asyncMethod.IsIAsyncEnumerableReturningAsync(compilation);
if (isEnumerable)
{
// IAsyncEnumerable<TResult>
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_Collections_Generic_IAsyncEnumerable_T).Construct(elementType));
}
// IAsyncEnumerator<TResult>
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_Collections_Generic_IAsyncEnumerator_T).Construct(elementType));
// IValueTaskSource<bool>
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_Threading_Tasks_Sources_IValueTaskSource_T).Construct(compilation.GetSpecialType(SpecialType.System_Boolean)));
// IValueTaskSource
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_Threading_Tasks_Sources_IValueTaskSource));
// IAsyncDisposable
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_IAsyncDisposable));
}
interfaces.Add(compilation.GetWellKnownType(WellKnownType.core_runtime_compiler_IAsyncStateMachine));
_interfaces = interfaces.ToImmutableAndFree();
_constructor = isIterator ? (MethodSymbol) new IteratorConstructor(this) : new AsyncConstructor(this);
}
