Class SimplePositionalPattern

All Implemented Interfaces:
ExportAgent, Locatable, IdentityComparable, Traceable

public final class SimplePositionalPattern extends Pattern
A SimplePositionalPattern is a pattern of the form A[N] where A is an axis expression using the child axis and P is a numeric literal.
  • Constructor Details

    • SimplePositionalPattern

      public SimplePositionalPattern(NodeTest nodeTest, int position)
      Create a SimplePositionalPattern
      Parameters:
      nodeTest - the test that the node must satisfy
      position - the required position of the node
  • Method Details

    • getPosition

      public int getPosition()
      Get the required position
      Returns:
      the integer appearing as the filter predicate
    • getNodeTest

      public NodeTest getNodeTest()
      Get the node test
      Returns:
      the node test used
    • matches

      public boolean matches(Item item, XPathContext context)
      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
    • 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 an ItemType 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
    • 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
    • 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
    • matchesBeneathAnchor

      public boolean matchesBeneathAnchor(NodeInfo node, NodeInfo anchor, XPathContext context)
      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
    • 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
    • reconstruct

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

      public void export(ExpressionPresenter presenter)
      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