Class VennPattern

    • Constructor Detail

      • VennPattern

        public VennPattern​(Pattern p1,
                           Pattern p2)
        Constructor
        Parameters:
        p1 - the left-hand operand
        p2 - the right-hand operand
    • Method Detail

      • setExecutable

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

        public Pattern analyze​(ExpressionVisitor visitor,
                               ExpressionVisitor.ContextItemType 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 at the point where the pattern is defined. Set to null if it is known that the context item is undefined.
        Returns:
        the optimised Pattern
        Throws:
        XPathException - if a static error is discovered
      • 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
      • 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
      • replaceSubExpression

        public boolean replaceSubExpression​(Expression original,
                                            Expression replacement)
        Replace a subexpression by a replacement subexpression
        Overrides:
        replaceSubExpression in class Pattern
        Parameters:
        original - the expression to be replaced
        replacement - the new expression to be inserted in its place
        Returns:
        true if the replacement was carried out
      • setOriginalText

        public void setOriginalText​(java.lang.String pattern)
        Set the original text
        Overrides:
        setOriginalText in class Pattern
        Parameters:
        pattern - the original text of the pattern
      • 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
      • 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
      • getVariableBindingExpression

        public Expression getVariableBindingExpression()
      • gatherComponentPatterns

        public void gatherComponentPatterns​(java.util.Set set)
        Gather the component (non-Venn) patterns of this Venn pattern
        Parameters:
        set - the set into which the components will be added
      • 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
      • getItemType

        public ItemType getItemType()
        Get an ItemType that all the items matching this pattern must satisfy
        Specified by:
        getItemType in class Pattern
        Returns:
        an ItemType, as specific as possible, which all the matching items 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 java.util.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​(java.lang.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​(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