Package net.sf.saxon.pattern

Class UnionPattern

java.lang.Object
net.sf.saxon.pattern.Pattern
net.sf.saxon.pattern.UnionPattern
All Implemented Interfaces:
Serializable, SourceLocator, Container, PatternFinder
public class UnionPattern extends Pattern
A pattern formed as the union (or) of two other patterns
See Also:

  • Field Details

  • Constructor Details

    • UnionPattern

      public UnionPattern(Pattern p1, Pattern p2)
      Constructor
      Parameters:
      p1 - the left-hand operand
      p2 - the right-hand operand

  • Method Details

    • setExecutable

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

    • simplify

      public Pattern simplify(ExpressionVisitor visitor) throws XPathException
      Simplify the pattern: perform any context-independent optimisations
      Overrides:
      simplify in class Pattern
      Parameters:
      visitor - an expression visitor
      Returns:
      the optimised Pattern
      Throws:
      XPathException

    • analyze

      public Pattern analyze(ExpressionVisitor visitor, ItemType 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, if known, at the point where the pattern is defined
      Returns:
      the optimised Pattern
      Throws:
      XPathException

    • setOriginalText

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

    • promote

      public void promote(PromotionOffer offer) throws XPathException
      Description copied from class: Pattern
      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
      Throws:
      XPathException - if any error is detected

    • replaceSubExpression

      public boolean replaceSubExpression(Expression original, Expression replacement)
      Description copied from interface: Container
      Replace one subexpression by a replacement subexpression
      Specified by:
      replaceSubExpression in interface Container
      Overrides:
      replaceSubExpression in class Pattern
      Parameters:
      original - the original subexpression
      replacement - the replacement subexpression
      Returns:
      true if the original subexpression was 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

    • gatherComponentPatterns

      public void gatherComponentPatterns(Set set)
      Gather the component (non-union) patterns of this union pattern
      Parameters:
      set - the set into which the components will be added

    • matches

      public boolean matches(NodeInfo e, XPathContext context) throws XPathException
      Determine if the supplied node matches the pattern
      Specified by:
      matches in class Pattern
      Parameters:
      e - 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

    • 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

    • getNodeTest

      public NodeTest getNodeTest()
      Get a NodeTest that all the nodes matching this pattern must satisfy
      Specified by:
      getNodeTest in class Pattern
      Returns:
      a NodeTest, as specific as possible, which all the matching nodes 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 Iterator iterateSubExpressions()
      Iterate over the subexpressions within this pattern
      Overrides:
      iterateSubExpressions in class Pattern
      Returns:
      an iterator over the subexpressions.

    • getLHS

      public Pattern getLHS()
      Get the LHS of the union
      Returns:
      the first operand of the union

    • getRHS

      public Pattern getRHS()
      Get the RHS of the union
      Returns:
      the second operand of the union

    • setSystemId

      public void setSystemId(String systemId)
      Override method to set the system ID, so it's set on both halves
      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 system ID, so it's set on both halves
      Overrides:
      setLineNumber in class Pattern
      Parameters:
      lineNumber - the line number of the pattern in the source module

    • equals

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

    • hashCode

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