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 Details

    • AncestorQualifiedPattern

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

    • operands

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

      public boolean equals(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