Package net.sf.saxon.pattern

Class Pattern

  • All Implemented Interfaces:
    java.io.Serializable, javax.xml.transform.SourceLocator, Container
    Direct Known Subclasses:
    IDPattern, KeyPattern, LocationPathPattern, NodeTestPattern, UnionPattern
    public abstract class Pattern
extends java.lang.Object
implements java.io.Serializable, Container
    A Pattern represents the result of parsing an XSLT pattern string.
    Patterns are created by calling the static method Pattern.make(string).
    The pattern is used to test a particular node by calling match().
    See Also:
    Serialized Form

    • Constructor Detail

      • Pattern

        public Pattern()

    • Method Detail

      • make

        public static Pattern make​(java.lang.String pattern,
                           StaticContext env,
                           Executable exec)
                    throws XPathException
        Static method to make a Pattern by parsing a String.
        Parameters:
        pattern - The pattern text as a String
        env - An object defining the compile-time context for the expression
        Returns:
        The pattern object
        Throws:
        XPathException

      • getExecutable

        public Executable getExecutable()
        Description copied from interface: Container
        Get the Executable (representing a complete stylesheet or query) of which this Container forms part
        Specified by:
        getExecutable in interface Container

      • setExecutable

        public void setExecutable​(Executable executable)

      • setOriginalText

        public void setOriginalText​(java.lang.String text)
        Set the original text of the pattern for use in diagnostics

      • simplify

        public Pattern simplify​(StaticContext env)
                 throws XPathException
        Simplify the pattern by applying any context-independent optimisations. Default implementation does nothing.
        Returns:
        the optimised Pattern
        Throws:
        XPathException

      • analyze

        public Pattern analyze​(StaticContext env,
                       ItemType contextItemType)
                throws XPathException
        Type-check the pattern. Default implementation does nothing. This is only needed for patterns that contain variable references or function calls.
        Returns:
        the optimised Pattern
        Throws:
        XPathException

      • getDependencies

        public int getDependencies()
        Get the dependencies of the pattern. The only possible dependency for a pattern is on local variables. This is analyzed in those patterns where local variables may appear.

      • iterateSubExpressions

        public java.util.Iterator iterateSubExpressions()
        Iterate over the subexpressions within this pattern

      • promote

        public void promote​(PromotionOffer offer)
             throws XPathException
        Offer promotion for subexpressions within this pattern. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

        Unlike the corresponding method on Expression, this method does not return anything: it can make internal changes to the pattern, but cannot return a different pattern. Only certain kinds of promotion are applicable within a pattern: specifically, promotions affecting local variable references within the pattern.

        Parameters:
        offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression
        Throws:
        XPathException - if any error is detected

      • setSystemId

        public void setSystemId​(java.lang.String systemId)
        Set the system ID where the pattern occurred

      • setLineNumber

        public void setLineNumber​(int lineNumber)
        Set the line number where the pattern occurred

      • matches

        public abstract boolean matches​(NodeInfo node,
                                XPathContext context)
                         throws XPathException
        Determine whether this Pattern matches the given Node. This is the main external interface for matching patterns: it sets current() to the node being tested
        Parameters:
        node - The NodeInfo representing the Element or other node to be tested against the Pattern
        context - The dynamic context. Only relevant if the pattern uses variables, or contains calls on functions such as document() or key().
        Returns:
        true if the node matches the Pattern, false otherwise
        Throws:
        XPathException

      • internalMatches

        protected boolean internalMatches​(NodeInfo node,
                                  XPathContext context)
                           throws XPathException
        Determine whether this Pattern matches the given Node. This is an internal interface used for matching sub-patterns; it does not alter the value of current(). The default implementation is identical to matches().
        Parameters:
        node - The NodeInfo representing the Element or other node to be tested against the Pattern
        context - The dynamic context. Only relevant if the pattern uses variables, or contains calls on functions such as document() or key().
        Returns:
        true if the node matches the Pattern, false otherwise
        Throws:
        XPathException

      • getNodeKind

        public int getNodeKind()
        Determine the types of nodes to which this pattern applies. Used for optimisation. For patterns that match nodes of several types, return Type.NODE
        Returns:
        the type of node matched by this pattern. e.g. Type.ELEMENT or Type.TEXT

      • getFingerprint

        public int getFingerprint()
        Determine the name fingerprint of nodes to which this pattern applies. Used for optimisation.
        Returns:
        A fingerprint that the nodes must match, or -1 if it can match multiple fingerprints

      • getNodeTest

        public abstract NodeTest getNodeTest()
        Get a NodeTest that all the nodes matching this pattern must satisfy

      • getDefaultPriority

        public double getDefaultPriority()
        Determine the default priority to use if this pattern appears as a match pattern for a template with no explicit priority attribute.

      • getSystemId

        public java.lang.String getSystemId()
        Get the system id of the entity in which the pattern occurred
        Specified by:
        getSystemId in interface javax.xml.transform.SourceLocator

      • getLineNumber

        public int getLineNumber()
        Get the line number on which the pattern was defined
        Specified by:
        getLineNumber in interface javax.xml.transform.SourceLocator

      • getColumnNumber

        public int getColumnNumber()
        Get the column number (always -1)
        Specified by:
        getColumnNumber in interface javax.xml.transform.SourceLocator

      • getPublicId

        public java.lang.String getPublicId()
        Get the public ID (always null)
        Specified by:
        getPublicId in interface javax.xml.transform.SourceLocator

      • toString

        public java.lang.String toString()
        Get the original pattern text
        Overrides:
        toString in class java.lang.Object

      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                    Expression replacement)
        Description copied from interface: Container
        Replace one subexpression by a replacement subexpression
        Specified by:
        replaceSubExpression in interface Container
        Parameters:
        original - the original subexpression
        replacement - the replacement subexpression
        Returns:
        true if the original subexpression was found