Boo.Lang.Compiler.Steps.ProcessMethodBodies.BindNullableOperation C# (CSharp) Метод

        bool BindNullableOperation(BinaryExpression node)
        {
            if (!IsNullableOperation(node))
                return false;

            if (BinaryOperatorType.ReferenceEquality == node.Operator)
            {
                node.Operator = BinaryOperatorType.Equality;
                return BindNullableComparison(node);
            }
            else if (BinaryOperatorType.ReferenceInequality == node.Operator)
            {
                node.Operator = BinaryOperatorType.Inequality;
                return BindNullableComparison(node);
            }

            IType lhs = GetExpressionType(node.Left);
            IType rhs = GetExpressionType(node.Right);
            bool lhsIsNullable = TypeSystemServices.IsNullable(lhs);
            bool rhsIsNullable = TypeSystemServices.IsNullable(rhs);

            if (BinaryOperatorType.Assign == node.Operator)
            {
                if (lhsIsNullable)
                {
                    if (rhsIsNullable)
                        return false;
                    BindNullableInitializer(node, node.Right, lhs);
                    return false;
                }
            }

            if (lhsIsNullable)
            {
                MemberReferenceExpression mre = new MemberReferenceExpression(node.Left, "Value");
                node.Replace(node.Left, mre);
                Visit(mre);
                mre.Annotate("nullableTarget", true);
            }
            if (rhsIsNullable)
            {
                MemberReferenceExpression mre = new MemberReferenceExpression(node.Right, "Value");
                node.Replace(node.Right, mre);
                Visit(mre);
                mre.Annotate("nullableTarget", true);
            }

            return false;
        }