net.sf.saxon.functions
Class CollatingFunction

java.lang.Object
  |
  +--net.sf.saxon.expr.ComputedExpression
        |
        +--net.sf.saxon.expr.FunctionCall
              |
              +--net.sf.saxon.functions.SystemFunction
                    |
                    +--net.sf.saxon.functions.CollatingFunction

All Implemented Interfaces:

Expression, java.io.Serializable

Direct Known Subclasses:

Compare, Contains, DeepEqual, DistinctValues, IndexOf, Minimax

public abstract class CollatingFunction

extends SystemFunction

Abstract superclass for all functions that take an optional collation argument

See Also:

Serialized Form

Field Summary

 

Fields inherited from class net.sf.saxon.functions.SystemFunction

operation

 

Fields inherited from class net.sf.saxon.expr.FunctionCall

argument

 

Fields inherited from class net.sf.saxon.expr.ComputedExpression

lineNumber, NO_ARGUMENTS, staticProperties

 

Constructor Summary

CollatingFunction()

 

Method Summary
protected  AtomicComparer	getAtomicComparer(int arg, XPathContext context)           Get a AtomicComparer that can be used to compare values
protected  java.util.Comparator	getCollator(int arg, XPathContext context, boolean useDefault)           Get a collator suitable for comparing strings.
Expression	preEvaluate(StaticContext env)           preEvaluate: this method suppresses compile-time evaluation by doing nothing (because collation definitions are not available statically)

 

Methods inherited from class net.sf.saxon.functions.SystemFunction

addContextDocumentArgument, checkArguments, computeCardinality, display, getDetails, getItemType, getName, getRequiredType, main, makeSystemFunction, useContextItemAsDefault

 

Methods inherited from class net.sf.saxon.expr.FunctionCall

analyze, checkArgumentCount, getNumberOfArguments, getSubExpressions, promote, setArguments, simplify, simplifyArguments

 

Methods inherited from class net.sf.saxon.expr.ComputedExpression

computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSourceLocator, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError

 

Methods inherited from class java.lang.Object

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

 

Constructor Detail

CollatingFunction

public CollatingFunction()

preEvaluate

public Expression preEvaluate(StaticContext env)

preEvaluate: this method suppresses compile-time evaluation by doing nothing (because collation definitions are not available statically)

Overrides:

preEvaluate in class FunctionCall

getAtomicComparer

protected AtomicComparer getAtomicComparer(int arg,
                                           XPathContext context)
                                    throws XPathException

Get a AtomicComparer that can be used to compare values

Parameters:

arg - the position of the argument (starting at 0) containing the collation name. If this argument was not supplied, the default collation is used

context - The dynamic evaluation context.

XPathException

getCollator

protected java.util.Comparator getCollator(int arg,
                                           XPathContext context,
                                           boolean useDefault)
                                    throws XPathException

Get a collator suitable for comparing strings. Returns the collator specified in the given function argument if present, otherwise returns the default collator.

Parameters:

arg - The argument position (counting from zero) that holds the collation URI if present

context - The dynamic context

useDefault - true if, in the absence of a collation argument, the default collation should be used; false if the codepoint collation should be used.

Returns:

a Comparator, which will either be a java.text.Collator, or a CodepointCollator

XPathException