com.icl.saxon.expr
Class NodeListExpression

java.lang.Object
  com.icl.saxon.expr.Expression
      com.icl.saxon.expr.NodeSetExpression
          com.icl.saxon.expr.NodeListExpression

public class NodeListExpression
extends NodeSetExpression

A NodeListExpression is an expression denoting a set of nodes sorted in document order.
It is not possible to write a NodeListExpression directly using XPath; however a node set expression is treated as a NodeListExpression when it appears in certain contexts, specifically the select attribute of xsl:apply-templates or xsl:for-each.

Field Summary

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

Constructor Summary

NodeListExpression(Expression exp)
Constructor

Method Summary

void	display(int level) Diagnostic print of expression structure
NodeEnumeration	enumerate(Context c, boolean sort) Return an enumeration that returns the nodes in document order
int	getDependencies() Determine which aspects of the context the expression depends on.
Expression	reduce(int dependencies, Context context) Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Expression	simplify() Simplify the expression

Methods inherited from class com.icl.saxon.expr.NodeSetExpression

evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsString, getDataType, outputStringValue, selectFirst

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, evaluateAsNumber, getStaticContext, indent, isContextDocumentNodeSet, make, setStaticContext, usesCurrent

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NodeListExpression

public NodeListExpression(Expression exp)

Constructor

Parameters:

exp - The expression that delivers the unsorted node-set

Method Detail

simplify

public Expression simplify()
                    throws XPathException

Simplify the expression

Overrides:

simplify in class Expression

Returns:

the simplified expression

Throws:

XPathException

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

Specified by:

getDependencies in class 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.

Specified by:

reduce in class Expression

Parameters:

dependencies - The dependencies to be removed

context - The context to be used for the partial evaluation

Returns:

a new expression that does not have any of the specified dependencies

Throws:

XPathException

enumerate

public NodeEnumeration enumerate(Context c,
                                 boolean sort)
                          throws XPathException

Return an enumeration that returns the nodes in document order

Specified by:

enumerate in class NodeSetExpression

Parameters:

c - the evaluation context

sort: - ignored, this class is used because the enumeration is always in document order

Throws:

XPathException - when the expression does not return a nodeset.

display

public void display(int level)

Diagnostic print of expression structure

Specified by:

display in class Expression