net.sf.saxon.type
Class AnyFunctionType

java.lang.Object
  net.sf.saxon.type.AnyFunctionType

All Implemented Interfaces:

Serializable, FunctionItemType, ItemType

Direct Known Subclasses:

FunctionType

public class AnyFunctionType
extends Object
implements FunctionItemType

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

See Also:

Serialized Form

Field Summary

static AnyFunctionType	ANY_FUNCTION
static SequenceType	SINGLE_FUNCTION

Constructor Summary

AnyFunctionType()

Method Summary

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.
ItemType	getSuperType(TypeHierarchy th) Get the type from which this item type is derived by restriction.
boolean	isAtomicType() Determine whether this item type is atomic (that is, whether it can ONLY match atomic values)
boolean	isAtomizable() Ask whether values of this type are atomizable
Expression	makeFunctionSequenceCoercer(Expression exp, RoleLocator role, ExpressionVisitor visitor) Create an expression whose effect is to apply function coercion to coerce a function from this type to another 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.
String	toString(NamePool pool) Produce a representation of this type name for use in error messages.

Methods inherited from class java.lang.Object

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

Field Detail

ANY_FUNCTION

public static 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)

isAtomicType

public boolean isAtomicType()

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

Specified by:

isAtomicType in interface ItemType

Returns:

true if this is ANY_ATOMIC_TYPE or a subtype thereof

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 -

config -

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 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

getPrimitiveType

public 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

toString

public String toString(NamePool pool)

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

Specified by:

toString in interface ItemType

Parameters:

pool - the name pool

Returns:

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

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,
                                              ExpressionVisitor 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