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

        void ProcessLenInvocation(MethodInvocationExpression node)
        {
            if ((node.Arguments.Count < 1) || (node.Arguments.Count > 2))
            {
                Error(node, CompilerErrorFactory.MethodArgumentCount(node.Target, "len", node.Arguments.Count));
                return;
            }

            Expression resultingNode = null;

            Expression target = node.Arguments[0];
            IType type = GetExpressionType(target);
            bool isArray = IsAssignableFrom(TypeSystemServices.ArrayType, type);

            if ((!isArray) && (node.Arguments.Count != 1))
            {
                Error(node, CompilerErrorFactory.MethodArgumentCount(node.Target, "len", node.Arguments.Count));
            }
            if (TypeSystemServices.IsSystemObject(type))
            {
                resultingNode = CodeBuilder.CreateMethodInvocation(MethodCache.RuntimeServices_Len, target);
            }
            else if (TypeSystemServices.StringType == type)
            {
                resultingNode = CodeBuilder.CreateMethodInvocation(target, MethodCache.String_get_Length);
            }
            else if (isArray)
            {
                if (node.Arguments.Count == 1)
                    resultingNode = CodeBuilder.CreateMethodInvocation(target, MethodCache.Array_get_Length);
                else
                    resultingNode = CodeBuilder.CreateMethodInvocation(target, MethodCache.Array_GetLength, node.Arguments[1]);
            }
            else if (IsAssignableFrom(TypeSystemServices.ICollectionType, type))
            {
                resultingNode = CodeBuilder.CreateMethodInvocation(target, MethodCache.ICollection_get_Count);
            }
            else if (GenericsServices.HasConstructedType(type, TypeSystemServices.ICollectionGenericType))
            {
                resultingNode = new MemberReferenceExpression(node.LexicalInfo, target, "Count");
                Visit(resultingNode);
            }
            else
            {
                Error(CompilerErrorFactory.InvalidLen(target, type));
            }

            if (null != resultingNode)
            {
                node.ParentNode.Replace(node, resultingNode);
            }
        }