net.sf.saxon.functions

Class Matches

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.expr.FunctionCall

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.Matches

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, Container, Expression, InstructionInfoProvider

public class Matches
extends SystemFunction

This class implements the matches() function for regular expression matching

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

locationId, staticProperties

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

Constructors

Constructor and Description
Matches()

Method Summary

Modifier and Type	Method and Description
Item	evaluateItem(XPathContext c) Evaluate the matches() function to give a Boolean value.
Expression	simplify(StaticContext env) Simplify and validate.
static RegularExpression	tryToCompile(Expression[] args, int patternArg, int flagsArg, StaticContext env) Try to precompile the arguments to the function.

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

addContextDocumentArgument, checkArguments, computeCardinality, computeSpecialProperties, display, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, main, makeSystemFunction, setDetails, useContextItemAsDefault

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

checkArgumentCount, getArguments, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, optimize, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionNameCode, simplifyArguments, typeCheck

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

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

Matches

public Matches()

Method Detail

simplify

public Expression simplify(StaticContext env)
                    throws XPathException

Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known

Specified by:

simplify in interface Expression

Overrides:

simplify in class FunctionCall

Parameters:

env - the static context

Returns:

the simplified expression

Throws:

StaticError - if any error is found (e.g. invalid regular expression)

XPathException - if an error is discovered during expression rewriting

evaluateItem

public Item evaluateItem(XPathContext c)
                  throws XPathException

Evaluate the matches() function to give a Boolean value.

Specified by:

evaluateItem in interface Expression

Overrides:

evaluateItem in class ComputedExpression

Parameters:

c - The dynamic evaluation context

Returns:

the result as a BooleanValue, or null to indicate the empty sequence

Throws:

XPathException - on an error

tryToCompile

public static RegularExpression tryToCompile(Expression[] args,
                                             int patternArg,
                                             int flagsArg,
                                             StaticContext env)
                                      throws XPathException

Try to precompile the arguments to the function. This method is shared by the implementations of the three XPath functions matches(), replace(), and tokenize().

Parameters:

args - the supplied arguments to the function, as an array

patternArg - the position of the argument containing the regular expression

flagsArg - the position of the argument containing the flags

Returns:

the compiled regular expression, or null indicating that the information is not available statically so it cannot be precompiled

Throws:

XPathException - if any failure occurs, in particular, if the regular expression is invalid