Package net.sf.saxon.type
Interface ItemType
- All Known Subinterfaces:
AtomicType
,FunctionItemType
,ItemTypeWithSequenceTypeCache
,PlainType
,RecordType
,UnionType
- All Known Implementing Classes:
AnyExternalObjectType
,AnyFunctionType
,AnyFunctionTypeWithAssertions
,AnyItemType
,AnyNodeTest
,ArrayItemType
,BuiltInAtomicType
,CombinedNodeTest
,ContentTypeTest
,DocumentNodeTest
,EnumerationType
,ErrorType
,ExternalObjectType
,JavaExternalObjectType
,LocalNameTest
,LocalUnionType
,MapType
,MultipleNodeKindTest
,NamespaceTest
,NameTest
,NameTestUnion
,NodeKindTest
,NodeSelector
,NodeTest
,NumericType
,RecordTest
,SameNameTest
,SchemaAttributeTest
,SchemaElementTest
,SelfReferenceRecordTest
,SpecificFunctionType
,UserAtomicType
,UserUnionType
public interface ItemType
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 TypeMethodDescriptionexplainMismatch
(Item item, TypeHierarchy th) Get extra diagnostic information about why a supplied item does not conform to this item type, if available.Get the item type of the atomic values that will be produced when an item of this type is atomizedGet an alphabetic code representing the type, or at any rate, the nearest built-in type from which this type is derived.double
Get the default priority when this ItemType is used as an XSLT patterndefault String
Get the full alpha code for this item type.getGenre()
Determine the Genre (top-level classification) of this typedefault double
Get the default priority normalized into the range 0 to 1Get the primitive item type corresponding to this item type.int
Get the primitive type corresponding to this item type.getUType()
Get the correspondingUType
.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, TypeHierarchy th) Test whether a given item conforms to this typedefault String
Return a string representation of this ItemType suitable for use in stylesheet export files.
-
Method Details
-
getGenre
Genre getGenre()Determine the Genre (top-level classification) of this type- Returns:
- the Genre to which this type belongs, for example node or atomic value
-
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). Return false if this is a union type whose member types are not all known.
-
matches
Test whether a given item conforms to this type- Parameters:
item
- The item to be testedth
- The type hierarchy cache. Currently used only when matching function items.- Returns:
- true if the item is an instance of this type; false otherwise
-
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
-
getUType
UType getUType()Get the correspondingUType
. A UType is a union of primitive item types.- Returns:
- the smallest UType that subsumes this item type
-
getDefaultPriority
double getDefaultPriority()Get the default priority when this ItemType is used as an XSLT pattern- Returns:
- the default priority
-
getNormalizedDefaultPriority
default double getNormalizedDefaultPriority()Get the default priority normalized into the range 0 to 1- Returns:
- the default priority plus one divided by two
-
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, or null if it is known that atomization will throw an error.
-
isAtomizable
Ask whether values of this type are atomizable- Parameters:
th
- the type hierarchy cache- Returns:
- true if some or all instances of this type can be successfully atomized; false if no instances of this type can be atomized
-
getBasicAlphaCode
String getBasicAlphaCode()Get an alphabetic code representing the type, or at any rate, the nearest built-in type from which this type is derived. The codes are designed so that for any two built-in types A and B, alphaCode(A) is a prefix of alphaCode(B) if and only if A is a supertype of B.- Returns:
- the alphacode for the nearest containing built-in type. For example: for xs:string return "AS", for xs:boolean "AB", for node() "N", for element() "NE", for map(*) "FM", for array(*) "FA".
-
getFullAlphaCode
Get the full alpha code for this item type. As well as the basic alpha code, this contains additional information, for exampleelement(EFG)
has a basic alpha code ofNE
, but the full alpha code ofNE nQ{}EFG
.- Returns:
- the alpha code for the type
-
toExportString
Return a string representation of this ItemType suitable for use in stylesheet export files. This differs from the result of toString() in that it will not contain any references to anonymous types. Note that it may also use the Saxon extended syntax for union types and tuple types. The default implementation returns the result of callingtoString()
.- Returns:
- the string representation as an instance of the XPath SequenceType construct
-
explainMismatch
Get extra diagnostic information about why a supplied item does not conform to this item type, if available. If extra information is returned, it should be in the form of a complete sentence, minus the closing full stop. No information should be returned for obvious cases.- Parameters:
item
- the item that doesn't match this typeth
- the type hierarchy cache- Returns:
- optionally, a message explaining why the item does not match the type
-