com.saxonica.ee.trans

Class TokenMatchOperand

java.lang.Object

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

com.saxonica.ee.trans.TokenMatchOperand

public class TokenMatchOperand
extends Characteristic<IntSet>

Given an expression, this characteristic evaluates the set of hash keys corresponding to the whitespace-separated tokens in the string values of the items selected by that expression.

It is used typically in optimizing patterns in DITA stylesheets, where the pattern takes the form *[@class = ' topic/li '] or similar. In this example the characteristic will be obtained by tokenizing the value of @class on whitespace boundaries, and finding the hash code of the collation key of each of these tokens. This set of hash codes is then compared with the hashcode of the constant string ' topic/li '. The benefit comes only when a rule chain contains many rules with this same general structure, but different constant strings; the same set of hash codes will then be compared against each of the string constants in turn.

Constructor Summary

Constructors

Constructor and Description
TokenMatchOperand(Expression exp) Create a token match characteristic

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object obj)
IntSet	evaluate(XPathContext context) Evaluate the value of this characteristic for the context item
int	hashCode()
java.lang.String	toString()

Methods inherited from class com.saxonica.ee.trans.Characteristic

getSlotNumber, setSlotNumber

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

TokenMatchOperand

public TokenMatchOperand(Expression exp)

Create a token match characteristic

Parameters:

exp - the expression to be tokenized. In the case of DITA-OT stylesheets, this expression will generally be "@class".

Method Detail

evaluate

public IntSet evaluate(XPathContext context)
                throws XPathException

Description copied from class: Characteristic

Evaluate the value of this characteristic for the context item

Specified by:

evaluate in class Characteristic<IntSet>

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

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object