Class AncestorQualifiedPattern

  • All Implemented Interfaces:
    ExportAgent, Locatable, IdentityComparable, Traceable

    public final class AncestorQualifiedPattern
    extends Pattern
    An AncestorQualifiedPattern represents a path of the form A/B or A//B, where nodes must match the pattern B and also have a parent/ancestor (respectively) that matches A.
    • Constructor Detail

      • AncestorQualifiedPattern

        public AncestorQualifiedPattern​(Pattern base,
                                        Pattern upper,
                                        int axis)
    • Method Detail

      • operands

        public java.lang.Iterable<Operand> operands()
        Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation works off the results of iterateSubExpressions()

        If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

        Overrides:
        operands in class Expression
        Returns:
        an iterator containing the sub-expressions of this expression
      • bindCurrent

        public void bindCurrent​(LocalBinding binding)
        Replace any calls on current() by a variable reference bound to the supplied binding
        Overrides:
        bindCurrent in class Pattern
      • getBasePattern

        public Pattern getBasePattern()
        Get the base pattern, the pattern applying to the node itself
        Returns:
        the base pattern
      • 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 int getUpwardsAxis()
        Get the upwards axis, that is, the axis by which the upper pattern is reached. Typically Axis.PARENT or Axis.ANCESTOR
        Returns:
        the relevant axis
      • isMotionless

        public boolean isMotionless()
        Test whether a pattern is motionless, that is, whether it can be evaluated against a node without repositioning the input stream. This is a necessary condition for patterns used as the match pattern of a streamed template rule.
        Overrides:
        isMotionless in class Pattern
        Returns:
        true if the pattern is motionless, that is, if it can be evaluated against a streamed node without changing the position in the streamed input file
      • matchesCurrentGroup

        public boolean matchesCurrentGroup()
        Description copied from class: Pattern
        Ask whether the pattern is anchored on a call on current-group()
        Overrides:
        matchesCurrentGroup in class Pattern
        Returns:
        true if calls on matchesBeneathAnchor should test with all nodes in the current group as anchor nodes. If false, only the first node in a group is treated as the anchor node
      • simplify

        public Pattern simplify()
                         throws XPathException
        Simplify the pattern: perform any context-independent optimisations
        Overrides:
        simplify in class Pattern
        Returns:
        the simplified expression (or the original if unchanged, or if modified in-situ)
        Throws:
        XPathException - if an error is discovered during expression rewriting
      • typeCheck

        public Pattern typeCheck​(ExpressionVisitor visitor,
                                 ContextItemStaticInfo contextItemType)
                          throws XPathException
        Type-check the pattern, performing any type-dependent optimizations.
        Overrides:
        typeCheck in class Pattern
        Parameters:
        visitor - an expression visitor
        contextItemType - the type of the context item at the point where the pattern appears
        Returns:
        the optimised Pattern
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)
      • 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
      • allocateSlots

        public int allocateSlots​(SlotManager slotManager,
                                 int nextFree)
        Allocate slots to any variables used within the pattern
        Overrides:
        allocateSlots in class Pattern
        Parameters:
        slotManager - keeps track of slots
        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 whether the pattern matches a given item.
        Specified by:
        matches in class Pattern
        Parameters:
        item - the item to be tested
        context - The dynamic context.
        Returns:
        true if the pattern matches, else false
        Throws:
        XPathException - if an error occurs while matching the pattern
      • 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 an error occurs while matching the pattern (the caller will usually treat this the same as a false result)
      • getUType

        public UType getUType()
        Get a UType indicating which kinds of items this Pattern can match.
        Specified by:
        getUType in class Pattern
        Returns:
        a UType indicating all the primitive types of item that the pattern can match.
      • 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
      • convertToTypedPattern

        public Pattern convertToTypedPattern​(java.lang.String val)
                                      throws XPathException
        Convert the pattern to a typed pattern, in which an element name is treated as schema-element(N)
        Overrides:
        convertToTypedPattern in class Pattern
        Parameters:
        val - either "strict" or "lax" depending on the value of xsl:mode/@typed
        Returns:
        either the original pattern unchanged, or a new pattern as the result of the conversion
        Throws:
        XPathException - if the pattern cannot be converted
      • reconstruct

        public java.lang.String reconstruct()
        Get the original pattern text
        Overrides:
        reconstruct in class Pattern
      • equals

        public boolean equals​(java.lang.Object other)
        Determine whether this pattern is the same as another pattern
        Overrides:
        equals in class Expression
        Parameters:
        other - the other object
        Returns:
        true if the other operand is an expression and if it can be determined that the two expressions are equivalent, in the sense that they will always return the same result.
      • computeHashCode

        protected int computeHashCode()
        hashcode supporting equals()
        Overrides:
        computeHashCode in class Expression
        Returns:
        a computed hash code
      • export

        public void export​(ExpressionPresenter presenter)
                    throws XPathException
        Description copied from class: Expression
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        export in interface ExportAgent
        Specified by:
        export in class Pattern
        Parameters:
        presenter - the expression presenter used to display the structure
        Throws:
        XPathException - if the export fails, for example if an expression is found that won't work in the target environment.
      • copy

        public Pattern copy​(RebindingMap rebindings)
        Copy a pattern. This makes a deep copy.
        Specified by:
        copy in class Pattern
        Parameters:
        rebindings - variables that need to be re-bound
        Returns:
        the copy of the original pattern