net.sf.saxon.functions

Class Matches

public class Matches extends SystemFunction

This class implements the matches() function for regular expression matching
Method Summary
ItemevaluateItem(XPathContext c)
Evaluate the matches() function to give a Boolean value.
Expressionsimplify(StaticContext env)
Simplify and validate.
static RegularExpressiontryToCompile(Expression[] args, int patternArg, int flagsArg, StaticContext env)
Try to precompile the arguments to the function.

Method Detail

evaluateItem

public Item evaluateItem(XPathContext c)
Evaluate the matches() function to give a Boolean value.

Parameters: c The dynamic evaluation context

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

Throws: XPathException on an error

simplify

public Expression simplify(StaticContext env)
Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known

Returns: the simplified expression

Throws: net.sf.saxon.trans.StaticError if any error is found (e.g. invalid regular expression)

tryToCompile

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