net.sf.saxon.type

Class AnyFunctionType

java.lang.Object

net.sf.saxon.type.AnyFunctionType

All Implemented Interfaces:

FunctionItemType, ItemType

Direct Known Subclasses:

MapType, SpecificFunctionType

public class AnyFunctionType
extends Object
implements FunctionItemType

An ItemType representing the type function(). Subtypes represent function items with more specific type signatures.

Note that although this class has a singleton instance representing the type function(*), there are also likely to be instances of subclasses representing more specific function types.

Field Summary

Fields

Modifier and Type	Field and Description
static AnyFunctionType	ANY_FUNCTION
static SequenceType	SINGLE_FUNCTION

Constructor Summary

Constructors

Constructor and Description
AnyFunctionType()

Method Summary

Methods

Modifier and Type	Method and Description
SequenceType[]	getArgumentTypes() Get the argument types of the function
AtomicType	getAtomizedItemType() Get the item type of the atomic values that will be produced when an item of this type is atomized
static AnyFunctionType	getInstance() Get the singular instance of this type (Note however that subtypes of this type may have any number of instances)
ItemType	getPrimitiveItemType() Get the primitive item type corresponding to this item type.
int	getPrimitiveType() Get the primitive type corresponding to this item type.
SequenceType	getResultType() Get the result type
ItemType	getSuperType(TypeHierarchy th) Get the type from which this item type is derived by restriction.
boolean	isAtomicType() Determine whether this item type is an atomic type
boolean	isAtomizable() Ask whether values of this type are atomizable
boolean	isMapType() Ask whether this function item type is a map type.
boolean	isPlainType() Determine whether this item type is atomic (that is, whether it can ONLY match atomic values)
Expression	makeFunctionSequenceCoercer(Expression exp, RoleLocator role, TypeCheckerEnvironment visitor) Create an expression whose effect is to apply function coercion to coerce a function from this type to another type
boolean	matches(Item item, XPathContext context) Test whether a given item conforms to this type
boolean	matchesItem(Item item, boolean allowURIPromotion, Configuration config) Test whether a given item conforms to this type
int	relationship(FunctionItemType other, TypeHierarchy th) Determine the relationship of one function item type to another
String	toString() Produce a representation of this type name for use in error messages.
void	visitNamedSchemaComponents(SchemaComponentVisitor visitor) Visit all the schema components used in this ItemType definition

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ANY_FUNCTION

public static final AnyFunctionType ANY_FUNCTION

SINGLE_FUNCTION

public static SequenceType SINGLE_FUNCTION

Constructor Detail

AnyFunctionType

public AnyFunctionType()

Method Detail

getInstance

public static AnyFunctionType getInstance()

Get the singular instance of this type (Note however that subtypes of this type may have any number of instances)

Returns:

the singular instance of this type

isAtomicType

public boolean isAtomicType()

Determine whether this item type is an atomic type

Specified by:

isAtomicType in interface ItemType

Returns:

true if this is ANY_ATOMIC_TYPE or a subtype thereof

isPlainType

public boolean isPlainType()

Determine whether this item type is atomic (that is, whether it can ONLY match atomic values)

Specified by:

isPlainType in interface ItemType

Returns:

true if this is ANY_ATOMIC_TYPE or a subtype thereof

isMapType

public boolean isMapType()

Ask whether this function item type is a map type. In this case function coercion (to the map type) will never succeed.

Specified by:

isMapType in interface FunctionItemType

Returns:

true if this FunctionItemType is a map type

getArgumentTypes

public SequenceType[] getArgumentTypes()

Get the argument types of the function

Specified by:

getArgumentTypes in interface FunctionItemType

Returns:

the argument types, as an array of SequenceTypes, or null if this is the generic function type function(*)

matches

public boolean matches(Item item,
              XPathContext context)

Test whether a given item conforms to this type

Specified by:

matches in interface ItemType

Parameters:

item - The item to be tested

context - the XPath dynamic evaluation context

Returns:

true if the item is an instance of this type; false otherwise

matchesItem

public boolean matchesItem(Item item,
                  boolean allowURIPromotion,
                  Configuration config)

Test whether a given item conforms to this type

Specified by:

matchesItem in interface ItemType

Parameters:

item - The item to be tested

allowURIPromotion - if a URI value is to be treated as a string

config - The Saxon configuration

Returns:

true if the item is an instance of this type; false otherwise

getSuperType

public ItemType getSuperType(TypeHierarchy th)

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.

Specified by:

getSuperType in interface ItemType

Parameters:

th - the type hierarchy cache

Returns:

the supertype, or null if this type is item()

getPrimitiveItemType

public final 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 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. For function items it is the singular instance FunctionItemType.getInstance().

Specified by:

getPrimitiveItemType in interface ItemType

Returns:

the corresponding primitive type

getPrimitiveType

public final 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 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 is considered to be a primitive type.

Specified by:

getPrimitiveType in interface ItemType

Returns:

the integer fingerprint of the corresponding primitive type

toString

public String toString()

Produce a representation of this type name for use in error messages.

Overrides:

toString in class Object

Returns:

a string representation of the type, in notation resembling but not necessarily identical to XPath syntax

getAtomizedItemType

public AtomicType getAtomizedItemType()

Get the item type of the atomic values that will be produced when an item of this type is atomized

Specified by:

getAtomizedItemType in interface ItemType

Returns:

the item type of the atomic values that will be produced when an item of this type is atomized

isAtomizable

public boolean isAtomizable()

Ask whether values of this type are atomizable

Specified by:

isAtomizable in interface ItemType

Returns:

true unless it is known that these items will be elements with element-only content, in which case return false

relationship

public int relationship(FunctionItemType other,
               TypeHierarchy th)

Determine the relationship of one function item type to another

Specified by:

relationship in interface FunctionItemType

Returns:

for example TypeHierarchy.SUBSUMES, TypeHierarchy.SAME_TYPE

makeFunctionSequenceCoercer

public Expression makeFunctionSequenceCoercer(Expression exp,
                                     RoleLocator role,
                                     TypeCheckerEnvironment visitor)
                                       throws XPathException

Create an expression whose effect is to apply function coercion to coerce a function from this type to another type

Specified by:

makeFunctionSequenceCoercer in interface FunctionItemType

Parameters:

exp - the expression that delivers the supplied sequence of function items (the ones in need of coercion)

role - information for use in diagnostics

visitor - the expression visitor, supplies context information

Returns:

the coerced function, a function that calls the original function after checking the parameters

Throws:

XPathException

visitNamedSchemaComponents

public void visitNamedSchemaComponents(SchemaComponentVisitor visitor)
                                throws XPathException

Visit all the schema components used in this ItemType definition

Specified by:

visitNamedSchemaComponents in interface ItemType

Parameters:

visitor - the visitor class to be called when each component is visited

Throws:

XPathException - if an error occurs

getResultType

public SequenceType getResultType()

Get the result type

Specified by:

getResultType in interface FunctionItemType

Returns:

the result type