com.icl.saxon.expr
Class UnionExpression
(package private) class UnionExpression
An expression representing a nodeset that is a union of two other NodeSets
void | display(int level)- Diagnostic print of expression structure
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NodeEnumeration | enumerate(Context c, boolean sort)- Evaluate the union expression.
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int | getDependencies()- Determine which aspects of the context the expression depends on.
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boolean | isContextDocumentNodeSet()- Determine, in the case of an expression whose data type is Value.NODESET,
whether all the nodes in the node-set are guaranteed to come from the same
document as the context node.
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Expression | reduce(int dependencies, Context context)- Perform a partial evaluation of the expression, by eliminating specified dependencies
on the context.
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Expression | simplify()- Simplify an expression
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containsReferences, display, enumerate, evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getDependencies, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, reduce, setStaticContext, simplify, usesCurrent |
UnionExpression
public UnionExpression(Expression p1,
Expression p2) Constructor
p1 - the left-hand operandp2 - the right-hand operand
display
public void display(int level)
Diagnostic print of expression structure
- display in interface Expression
enumerate
public NodeEnumeration enumerate(Context c,
boolean sort)
throws XPathException Evaluate the union expression. The result will always be sorted in document order,
with duplicates eliminated
- enumerate in interface NodeSetExpression
c - The context for evaluationsort - Request the nodes in document order (they will be, regardless)
- a NodeSetValue representing the union of the two operands
getDependencies
public int getDependencies()
Determine which aspects of the context the expression depends on. The result is
a bitwise-or'ed value composed from constants such as Context.VARIABLES and
Context.CURRENT_NODE
- getDependencies in interface Expression
isContextDocumentNodeSet
public boolean isContextDocumentNodeSet()
Determine, in the case of an expression whose data type is Value.NODESET,
whether all the nodes in the node-set are guaranteed to come from the same
document as the context node. Used for optimization.
- isContextDocumentNodeSet in interface Expression
reduce
public Expression reduce(int dependencies,
Context context)
throws XPathException Perform a partial evaluation of the expression, by eliminating specified dependencies
on the context.
- reduce in interface Expression
dependencies - The dependencies to be removedcontext - The context to be used for the partial evaluation
- a new expression that does not have any of the specified
dependencies