Package net.sf.saxon.pattern

Class LocationPathPattern

  • All Implemented Interfaces:
    java.io.Serializable, javax.xml.transform.SourceLocator, Container, PatternFinder
    public final class LocationPathPattern
extends Pattern
    A LocationPathPattern represents a path, for example of the form A/B/C... The components are represented as a linked list, each component pointing to its predecessor
    See Also:
    Serialized Form

    • Field Detail

      • equivalentExpr

        protected Expression equivalentExpr

      • firstElementPattern

        protected boolean firstElementPattern

      • lastElementPattern

        protected boolean lastElementPattern

      • specialFilter

        protected boolean specialFilter

    • Constructor Detail

      • LocationPathPattern

        public LocationPathPattern()
        Create a LocationPathPattern

    • Method Detail

      • setNodeTest

        public void setNodeTest​(NodeTest test)
        Set the NodeTest
        Parameters:
        test - the NodeTest

      • setUpperPattern

        public void setUpperPattern​(byte axis,
                            Pattern upper)
        Set the superior pattern (matching a parent or ancestor node
        Parameters:
        axis - the axis (parent or ancestor) connecting to the upper pattern
        upper - the pattern that a parent or ancestor must match

      • addFilter

        public void addFilter​(Expression filter)
        Add a filter to the pattern (while under construction)
        Parameters:
        filter - The predicate (a boolean expression or numeric expression) to be added

      • setLineNumber

        public void setLineNumber​(int lineNumber)
        Description copied from class: Pattern
        Set the line number where the pattern occurred
        Overrides:
        setLineNumber in class Pattern
        Parameters:
        lineNumber - the line number of the pattern in the source module

      • setSystemId

        public void setSystemId​(java.lang.String systemId)
        Description copied from class: Pattern
        Set the system ID where the pattern occurred
        Overrides:
        setSystemId in class Pattern
        Parameters:
        systemId - the URI of the module containing the pattern

      • setExecutable

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

      • setVariableBindingExpression

        public void setVariableBindingExpression​(Expression exp)
        Set an expression used to bind the variable that represents the value of the current() function
        Overrides:
        setVariableBindingExpression in class Pattern
        Parameters:
        exp - the expression that binds the variable

      • getFilters

        public Expression[] getFilters()
        Get the filters assocated with the last step in the pattern
        Returns:
        an array of expression holding the filter predicates in order

      • getUpperPattern

        public Pattern getUpperPattern()
        Get the pattern applying to the parent node, if there is one
        Returns:
        the parent pattern, for example if the pattern is a/b[1]/c then the parent pattern is a/b[1]

      • getUpwardsAxis

        public byte getUpwardsAxis()
        Get the upwards axis, that is, the axis by which the upper pattern is reached. Typically Axis.PARENT or Axis.ANCESTOR

      • selectsOutwards

        public boolean selectsOutwards()
        Test whether any predicate within the pattern contains a prohibited selection, that is, use of an axis such as child, descendant, following-sibling

      • 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. Default implementation returns an empty sequence

      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                    Expression replacement)
        Replace one subexpression by a replacement subexpression
        Overrides:
        replaceSubExpression in class Pattern
        Parameters:
        original - the original subexpression
        replacement - the replacement subexpression
        Returns:
        true if the original subexpression is found

      • 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

      • 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

      • matches

        public boolean matches​(Item item,
                       XPathContext context)
                throws XPathException
        Determine whether the pattern matches a given item.
        Specified by:
        matches in class Pattern
        Parameters:
        item - the item to be tested
        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 pattern matches, else false
        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

      • internalMatches

        protected boolean internalMatches​(NodeInfo node,
                                  NodeInfo anchor,
                                  XPathContext context)
                           throws XPathException
        Test whether the pattern matches, but without changing the current() node
        Overrides:
        internalMatches 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(). @return true if the node matches the Pattern, false otherwise
        Returns:
        true if the pattern matches the supplied node
        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 Node.NODE
        Overrides:
        getNodeKind in class Pattern
        Returns:
        the type of node matched by this pattern. e.g. Node.ELEMENT or Node.TEXT

      • getFingerprint

        public int getFingerprint()
        Determine the fingerprint of nodes to which this pattern applies. Used for optimisation.
        Overrides:
        getFingerprint in class Pattern
        Returns:
        the fingerprint of nodes matched by this pattern.

      • 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

      • isPositional

        public boolean isPositional​(TypeHierarchy th)
        Determine if the pattern uses positional filters
        Parameters:
        th - the type hierarchy cache
        Returns:
        true if there is a numeric filter in the pattern, or one that uses the position() or last() functions

      • resolveCurrent

        public void resolveCurrent​(LetExpression let,
                           PromotionOffer offer,
                           boolean topLevel)
                    throws XPathException
        If the pattern contains any calls on current(), this method is called to modify such calls to become variable references to a variable declared in a specially-allocated local variable
        Overrides:
        resolveCurrent in class Pattern
        Parameters:
        let - the expression that assigns the local variable. This returns a dummy result, and is executed just before evaluating the pattern, to get the value of the context item into the variable.
        offer - A PromotionOffer used to process the expressions and change the call on current() into a variable reference
        topLevel -
        Throws:
        XPathException

      • 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