System.Xml.Xsl.XmlQueryTypeFactory.ChildrenOf C# (CSharp) Method

        public XmlQueryType ChildrenOf(XmlQueryType source, XmlQueryType filter) {
            Debug.Assert(filter.IsNode && filter.Count == 1 && filter.IsSingleton);
            List<XmlQueryType> list = new List<XmlQueryType>();
            XmlQueryCardinality card = XmlQueryCardinality.None;

            foreach (XmlQueryType sourceItem in source) {
                switch (sourceItem.TypeCode) {
                case XmlTypeCode.Node:
                case XmlTypeCode.Document:
                case XmlTypeCode.Element:
                    XmlSchemaType sourceSchemaType = sourceItem.SchemaType;
                    XmlQueryCardinality itemCard = XmlQueryCardinality.None;
                    // Only element and document can have children
                    if (sourceSchemaType == XmlSchemaComplexType.UntypedAnyType) {
                        // content of xdt:untypedAny is element(*, xdt:untypedAny)*
                        itemCard = (AddFilteredPrime(list, UntypedElement, filter) * XmlQueryCardinality.ZeroOrMore);
                        itemCard += AddFilteredPrime(list, Text, filter);
                    }
                    else if (sourceSchemaType.Datatype != null) {
                        // Text is the only child node simple type can have
                        itemCard = AddFilteredPrime(list, Text, filter, true) * XmlQueryCardinality.ZeroOrOne;
                    }
                    else {
                        // Complex content
                        XmlSchemaComplexType complexType = (XmlSchemaComplexType)sourceSchemaType;
                        itemCard = AddChildParticle(list, complexType.ContentTypeParticle, filter);
                        if (complexType.ContentType == XmlSchemaContentType.Mixed) {
                            itemCard += AddFilteredPrime(list, Text, filter);
                        }
                    }
                    itemCard += AddFilteredPrime(list, PI, filter);
                    itemCard += AddFilteredPrime(list, Comment, filter);
                    card |= itemCard;
                    break;

                case XmlTypeCode.Attribute:
                case XmlTypeCode.ProcessingInstruction:
                case XmlTypeCode.Comment:
                case XmlTypeCode.Namespace:
                case XmlTypeCode.Text:
                    card |= XmlQueryCardinality.Zero;
                    break;

                default:
                    Debug.Assert(sourceItem.IsAtomicValue, "missed case for a node");
                    return null;
                }
            }
            // Make sure that cardinality is at least Zero
            return PrimeProduct(ChoiceType.Create(list), source.Cardinality * card);
        }