public XmlQueryType AttributesOf(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.Element:
XmlSchemaType sourceSchemaType = sourceItem.SchemaType;
if (sourceSchemaType == XmlSchemaComplexType.UntypedAnyType) {
// attfibutes of of xdt:untypedAny are attribute(*, xdt:untypedAtomic)*
card |= AddFilteredPrime(list, UntypedAttribute, filter) * XmlQueryCardinality.ZeroOrOne;
}
else {
// Only complex type can have attributes
XmlSchemaComplexType type = sourceSchemaType as XmlSchemaComplexType;
if (type != null) {
card |= AddAttributes(list, type.AttributeUses, type.AttributeWildcard, filter);
}
}
break;
case XmlTypeCode.Document:
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);
}