Class VennExpression

    • Constructor Detail

      • VennExpression

        public VennExpression​(Expression p1,
                              int op,
                              Expression p2)
        Constructor
        Parameters:
        p1 - the left-hand operand
        op - the operator (union, intersection, or difference)
        p2 - the right-hand operand
    • Method Detail

      • getItemType

        public final ItemType getItemType​(TypeHierarchy th)
        Determine the data type of the items returned by this expression
        Parameters:
        th -
        Returns:
        the data type
      • computeSpecialProperties

        public int computeSpecialProperties()
        Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.
        Overrides:
        computeSpecialProperties in class BinaryExpression
        Returns:
        StaticProperty.NON_CREATIVE. This is overridden for some subclasses.
      • typeCheck

        public Expression typeCheck​(StaticContext env,
                                    ItemType contextItemType)
                             throws XPathException
        Type-check the expression
        Specified by:
        typeCheck in interface Expression
        Overrides:
        typeCheck in class BinaryExpression
        Parameters:
        env - the static context of the expression
        contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE
        Returns:
        the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
        Throws:
        StaticError - if an error is discovered during this phase (typically a type error)
        XPathException
      • hashCode

        public int hashCode()
        Is this expression the same as another expression?
        Overrides:
        hashCode in class BinaryExpression
      • iterate

        public SequenceIterator iterate​(XPathContext c)
                                 throws XPathException
        Iterate over the value of the expression. The result will always be sorted in document order, with duplicates eliminated
        Specified by:
        iterate in interface Expression
        Overrides:
        iterate in class ComputedExpression
        Parameters:
        c - The context for evaluation
        Returns:
        a SequenceIterator representing the union of the two operands
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression