Class Matches

All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, InstructionInfo, Locator

public class Matches extends SystemFunction
This class implements the matches() function for regular expression matching
See Also:
  • Constructor Details

    • Matches

      public Matches()
  • Method Details

    • simplify

      public Expression simplify(ExpressionVisitor visitor) throws XPathException
      Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known
      Overrides:
      simplify in class FunctionCall
      Parameters:
      visitor - an expression visitor
      Returns:
      the simplified expression
      Throws:
      XPathException - if any error is found (e.g. invalid regular expression)
    • optimize

      public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
      Perform optimisation of an expression and its subexpressions.

      This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

      Overrides:
      optimize in class SystemFunction
      Parameters:
      visitor - an expression visitor
      contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
      Returns:
      the original expression, rewritten if appropriate to optimize execution
      Throws:
      XPathException - if an error is discovered during this phase (typically a type error)
    • getCompiledRegularExpression

      public RegularExpression getCompiledRegularExpression()
      Get the compiled regular expression, returning null if the regex has not been compiled
      Returns:
      the compiled regular expression, or null
    • evaluateItem

      public Item evaluateItem(XPathContext c) throws XPathException
      Evaluate the matches() function to give a Boolean value.
      Overrides:
      evaluateItem in class Expression
      Parameters:
      c - The dynamic evaluation context
      Returns:
      the result as a BooleanValue, or null to indicate the empty sequence
      Throws:
      XPathException - on an error
    • evalMatches

      public boolean evalMatches(AtomicValue input, AtomicValue regex, CharSequence flags, XPathContext context) throws XPathException
      Interface used by compiled bytecode
      Parameters:
      input - the value to be tested
      regex - the regular expression
      flags - the flags
      context - the dynamic context
      Returns:
      true if the string matches the regex
      Throws:
      XPathException
    • 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
      env - the static context
      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