net.sf.saxon.expr

Class VennExpression

public class VennExpression extends BinaryExpression

An expression representing a nodeset that is a union, difference, or intersection of two other NodeSets

Constructor Summary
	VennExpression(Expression p1, int op, Expression p2) Constructor

Method Summary
int	computeCardinality() Determine the static cardinality of the expression
int	computeSpecialProperties() Get the static properties of this expression (other than its type).
boolean	effectiveBooleanValue(XPathContext context) Get the effective boolean value.
ItemType	getItemType(TypeHierarchy th) Determine the data type of the items returned by this expression
int	hashCode() Is this expression the same as another expression?
SequenceIterator	iterate(XPathContext c) Iterate over the value of the expression.
Expression	simplify(StaticContext env) Simplify the expression
Expression	typeCheck(StaticContext env, ItemType contextItemType) Type-check the expression

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

computeCardinality

public final int computeCardinality()

Determine the static cardinality of the expression

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.