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

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
Matches()
           
 
Method Summary
 Item evaluateItem(XPathContext c)
          Evaluate the matches() function to give a Boolean value.
static int setFlags(java.lang.String inFlags)
          Set the Java flags from the supplied XPath flags.
 Expression simplify(StaticContext env)
          Simplify and validate.
protected static java.util.regex.Pattern tryToCompile(Expression[] args, int patternArg, int flagsArg)
          Try to precompile the arguments to the function.
 
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, checkArguments, computeCardinality, display, getDetails, getItemType, getRequiredType, main, makeSystemFunction, setDetails, useContextItemAsDefault
 
Methods inherited from class net.sf.saxon.expr.FunctionCall
analyze, checkArgumentCount, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, preEvaluate, promote, setArguments, setFunctionNameCode, simplifyArguments
 
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getParentExpression, getPublicId, getSpecialProperties, getSystemId, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, 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
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

setFlags

public static int setFlags(java.lang.String inFlags)
                    throws StaticError
Set the Java flags from the supplied XPath flags.

Parameters:
inFlags - the flags as a string, e.g. "im"
Returns:
the flags as a bit-significant integer
Throws:
StaticError - if the supplied value is invalid

tryToCompile

protected static java.util.regex.Pattern tryToCompile(Expression[] args,
                                                      int patternArg,
                                                      int flagsArg)
                                               throws StaticError
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:
StaticError - if any failure occurs, in particular, if the regular expression is invalid

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