private IEnumerable<ITypeSymbol> InferTypeInYieldStatement(YieldStatementSyntax yieldStatement, SyntaxToken? previousToken = null)
{
// If we are position based, then we have to be after the return keyword
if (previousToken.HasValue && (previousToken.Value != yieldStatement.ReturnOrBreakKeyword || yieldStatement.ReturnOrBreakKeyword.IsKind(SyntaxKind.BreakKeyword)))
{
return SpecializedCollections.EmptyEnumerable<ITypeSymbol>();
}
var memberSymbol = GetDeclaredMemberSymbolFromOriginalSemanticModel(this.semanticModel, yieldStatement.GetAncestorOrThis<MemberDeclarationSyntax>());
var memberType = memberSymbol.TypeSwitch(
(IMethodSymbol method) => method.ReturnType,
(IPropertySymbol property) => property.Type);
if (memberType is INamedTypeSymbol)
{
if (memberType.OriginalDefinition.SpecialType == SpecialType.System_Collections_Generic_IEnumerable_T ||
memberType.OriginalDefinition.SpecialType == SpecialType.System_Collections_Generic_IEnumerator_T)
{
return SpecializedCollections.SingletonEnumerable(((INamedTypeSymbol)memberType).TypeArguments[0]);
}
}
return SpecializedCollections.EmptyEnumerable<ITypeSymbol>();
}
