Package net.sf.saxon.pattern

Class ConditionalPattern

  • All Implemented Interfaces:
    java.io.Serializable, javax.xml.transform.SourceLocator, Container, PatternFinder
    public class ConditionalPattern
extends Pattern
    A ConditionalPattern tests a node against one of a number of patterns depending on the value of a condition. This is used only as a streaming selection.
    See Also:
    Serialized Form

    • Constructor Detail

      • ConditionalPattern

        public ConditionalPattern​(Expression[] conditions,
                          Pattern[] patterns)

    • Method Detail

      • setExecutable

        public void setExecutable​(Executable executable)
        Set the executable containing this pattern
        Overrides:
        setExecutable in class Pattern
        Parameters:
        executable - the executable

      • analyze

        public Pattern analyze​(ExpressionVisitor visitor,
                       ExpressionVisitor.ContextItemType contextItemType)
                throws XPathException
        Type-check the pattern. This is only needed for patterns that contain variable references or function calls.
        Overrides:
        analyze in class Pattern
        Parameters:
        visitor - the expression visitor
        contextItemType - the type of the context item at the point where the pattern is defined. Set to null if it is known that the context item is undefined.
        Returns:
        the optimised Pattern
        Throws:
        XPathException - if a static error is discovered

      • promote

        public void promote​(PromotionOffer offer,
                    Expression parent)
             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.

        Overrides:
        promote in class 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
        parent -
        Throws:
        XPathException - if any error is detected

      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                    Expression replacement)
        Replace a subexpression by a replacement subexpression
        Overrides:
        replaceSubExpression in class Pattern
        Parameters:
        original - the expression to be replaced
        replacement - the new expression to be inserted in its place
        Returns:
        true if the replacement was carried out

      • setOriginalText

        public void setOriginalText​(java.lang.String pattern)
        Set the original text
        Overrides:
        setOriginalText in class Pattern
        Parameters:
        pattern - the original text of the pattern

      • allocateSlots

        public int allocateSlots​(StaticContext env,
                         SlotManager slotManager,
                         int nextFree)
        Allocate slots to any variables used within the pattern
        Overrides:
        allocateSlots in class Pattern
        Parameters:
        env - the static context in the XSLT stylesheet
        slotManager -
        nextFree - the next slot that is free to be allocated @return the next slot that is free to be allocated
        Returns:
        the next slot that is free to be allocated

      • matches

        public boolean matches​(Item item,
                       XPathContext context)
                throws XPathException
        Determine if the supplied node matches the pattern
        Specified by:
        matches in class Pattern
        Parameters:
        item - the node to be compared
        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 either of the operand patterns
        Throws:
        XPathException - if a dynamic error occurs during pattern matching

      • matchesBeneathAnchor

        public boolean matchesBeneathAnchor​(NodeInfo node,
                                    NodeInfo anchor,
                                    XPathContext context)
                             throws XPathException
        Determine whether this pattern matches a given Node within the subtree rooted at a given anchor node. This method is used when the pattern is used for streaming.
        Overrides:
        matchesBeneathAnchor in class Pattern
        Parameters:
        node - The NodeInfo representing the Element or other node to be tested against the Pattern
        anchor - The anchor node, which must match any AnchorPattern subpattern
        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 - if a dynamic error occurs during pattern matching

      • 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
        Overrides:
        getNodeKind in class Pattern
        Returns:
        the type of node matched by this pattern. e.g. Type.ELEMENT or Type.TEXT

      • getItemType

        public ItemType getItemType()
        Get a NodeTest that all the nodes matching this pattern must satisfy
        Specified by:
        getItemType in class Pattern
        Returns:
        an ItemType, as specific as possible, which all the matching items satisfy

      • 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.
        Overrides:
        getDependencies in class Pattern
        Returns:
        the dependencies, as a bit-significant mask

      • iterateSubExpressions

        public java.util.Iterator iterateSubExpressions()
        Iterate over the subexpressions within this pattern
        Overrides:
        iterateSubExpressions in class Pattern
        Returns:
        an iterator over the subexpressions.

      • setSystemId

        public void setSystemId​(java.lang.String systemId)
        Override method to set the system ID
        Overrides:
        setSystemId in class Pattern
        Parameters:
        systemId - the URI of the module containing the pattern

      • setLineNumber

        public void setLineNumber​(int lineNumber)
        Override method to set the line number
        Overrides:
        setLineNumber in class Pattern
        Parameters:
        lineNumber - the line number of the pattern in the source module

      • equals

        public boolean equals​(java.lang.Object other)
        Determine whether this pattern is the same as another pattern
        Overrides:
        equals in class java.lang.Object
        Parameters:
        other - the other object

      • hashCode

        public int hashCode()
        Hashcode supporting equals()
        Overrides:
        hashCode in class java.lang.Object