com.saxonica.ee.trans

Class Characteristic<T>

java.lang.Object

com.saxonica.ee.trans.Characteristic<T>

Direct Known Subclasses:

AncestorCharacteristic, GeneralComparisonOperand, NumericComparisonOperand, TokenMatchOperand

public abstract class Characteristic<T>
extends java.lang.Object

A Characteristic represents a distinguishing feature of an item that may be used by several patterns in a rule chain, and which can usefully be evaluated once for all rules in the rule chain. Characteristics are evaluated in the course of evaluating preconditions, and their values may be used again when evaluating a different precondition. For example (a classic DITA use case), the tokenized value of an element's @class attribute is a characteristic that may be used by several preconditions that test for the presence of particular tokens in the value.

Constructor Summary

Constructors

Constructor and Description
Characteristic()

Method Summary

Modifier and Type	Method and Description
abstract T	evaluate(XPathContext context) Evaluate the value of this characteristic for the context item
int	getSlotNumber() Get the slot number allocated to the value of this characteristic in the RuleSearchState
void	setSlotNumber(int slotNumber) Allocate a slot number to this characteristic in the RuleSearchState

Methods inherited from class java.lang.Object

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

Constructor Detail

Characteristic

public Characteristic()

Method Detail

getSlotNumber

public final int getSlotNumber()

Get the slot number allocated to the value of this characteristic in the RuleSearchState

Returns:

the allocated slot number

setSlotNumber

public final void setSlotNumber(int slotNumber)

Allocate a slot number to this characteristic in the RuleSearchState

Parameters:

slotNumber - the slot number to be allocated

evaluate

public abstract T evaluate(XPathContext context)
                    throws XPathException

Evaluate the value of this characteristic for the context item

Parameters:

context - the dynamic evaluation context; the context item is the item being matched

Returns:

the value of the characteristic

Throws:

XPathException - if evaluation of the characteristic fails