Package net.sf.saxon.type
Interface ItemType
- All Superinterfaces:
Serializable
- All Known Subinterfaces:
AtomicType
,FunctionItemType
,PlainType
- All Known Implementing Classes:
AnyChildNodeTest
,AnyFunctionType
,AnyItemType
,AnyNodeTest
,BuiltInAtomicType
,CombinedNodeTest
,ContentTypeTest
,DocumentNodeTest
,EmptySequenceTest
,ExternalObjectType
,LocalNameTest
,NamespaceTest
,NameTest
,NodeKindTest
,NodeTest
ItemType is an interface that allows testing of whether an Item conforms to an
expected type. ItemType represents the types in the type hierarchy in the XPath model,
as distinct from the schema model: an item type is either item() (matches everything),
a node type (matches nodes), an atomic type (matches atomic values), or empty()
(matches nothing). Atomic types, represented by the class AtomicType, are also
instances of SimpleType in the schema type hierarchy. Node Types, represented by
the class NodeTest, are also Patterns as used in XSLT.
Saxon assumes that apart from AnyItemType
(which corresponds to item()
and matches anything), every ItemType will be either an
AtomicType
, a NodeTest
,
or a FunctionItemType
. User-defined implementations of ItemType must therefore extend one of those
three classes/interfaces.
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionGet the item type of the atomic values that will be produced when an item of this type is atomizeddouble
Determine the default priority of this item type when used on its own as a PatternGet the primitive item type corresponding to this item type.int
Get the primitive type corresponding to this item type.Get the type from which this item type is derived by restriction.boolean
Determine whether this item type is an atomic typeboolean
Ask whether values of this type are atomizableboolean
Determine whether this item type is a plain type (that is, whether it can ONLY match atomic values)boolean
matches
(Item item, XPathContext context) Test whether a given item conforms to this typeboolean
matchesItem
(Item item, boolean allowURIPromotion, Configuration config) Test whether a given item conforms to this typeProduce a representation of this type name for use in error messages.void
Visit all the schema components used in this ItemType definition
-
Method Details
-
isAtomicType
boolean isAtomicType()Determine whether this item type is an atomic type- Returns:
- true if this is ANY_ATOMIC_TYPE or a subtype thereof
-
isPlainType
boolean isPlainType()Determine whether this item type is a plain type (that is, whether it can ONLY match atomic values)- Returns:
- true if this is ANY_ATOMIC_TYPE or a subtype thereof, or a "plain" union type (that is, unions of atomic types that impose no further restrictions)
-
matches
Test whether a given item conforms to this type- Parameters:
item
- The item to be testedcontext
- the XPath dynamic evaluation context- Returns:
- true if the item is an instance of this type; false otherwise
-
matchesItem
Test whether a given item conforms to this type- Parameters:
item
- The item to be testedallowURIPromotion
- if a URI value is to be treated as a stringconfig
- the Saxon configuration- Returns:
- true if the item is an instance of this type; false otherwise
-
getSuperType
Get the type from which this item type is derived by restriction. This is the supertype in the XPath type heirarchy, as distinct from the Schema base type: this means that the supertype of xs:boolean is xs:anyAtomicType, whose supertype is item() (rather than xs:anySimpleType).In fact the concept of "supertype" is not really well-defined, because the types form a lattice rather than a hierarchy. The only real requirement on this function is that it returns a type that strictly subsumes this type, ideally as narrowly as possible.
- Parameters:
th
- the type hierarchy cache- Returns:
- the supertype, or null if this type is item()
-
getPrimitiveItemType
ItemType getPrimitiveItemType()Get the primitive item type corresponding to this item type. For item(), this is Type.ITEM. For node(), it is Type.NODE. For specific node kinds, it is the value representing the node kind, for example Type.ELEMENT. For anyAtomicValue and union types it is Type.ATOMIC_VALUE. For numeric it is Type.NUMBER. For other atomic types it is the primitive type as defined in XML Schema, except that integer, xs:dayTimeDuration, and xs:yearMonthDuration are considered to be primitive types.- Returns:
- the corresponding primitive type
-
getPrimitiveType
int getPrimitiveType()Get the primitive type corresponding to this item type. For item(), this is Type.ITEM. For node(), it is Type.NODE. For specific node kinds, it is the value representing the node kind, for example Type.ELEMENT. For anyAtomicValue it is BuiltInAtomicType.ANY_ATOMIC. For numeric it is Type.NUMBER. For other atomic types it is the primitive type as defined in XML Schema, except that INTEGER is considered to be a primitive type.- Returns:
- the integer fingerprint of the corresponding primitive type
-
getDefaultPriority
double getDefaultPriority()Determine the default priority of this item type when used on its own as a Pattern- Returns:
- the default priority
-
toString
Produce a representation of this type name for use in error messages. Where this is a QName, it will use conventional prefixes- Parameters:
pool
- the name pool- Returns:
- a string representation of the type, in notation resembling but not necessarily identical to XPath syntax
-
getAtomizedItemType
PlainType getAtomizedItemType()Get the item type of the atomic values that will be produced when an item of this type is atomized- Returns:
- the best available item type of the atomic values that will be produced when an item of this type is atomized
-
isAtomizable
boolean isAtomizable()Ask whether values of this type are atomizable- Returns:
- true unless it is known that these items will be elements with element-only content, or function items, in which case return false
-
visitNamedSchemaComponents
Visit all the schema components used in this ItemType definition- Parameters:
visitor
- the visitor class to be called when each component is visited- Throws:
XPathException
- if an error occurs
-