com.icl.saxon.expr

Class ContextNodeExpression


public final class ContextNodeExpression
extends SingletonExpression

This class represents the expression ".", which always returns the context node.

Field Summary

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

staticContext

Method Summary

void
display(int level)
Diagnostic print of expression structure
int
getDependencies()
Determine which aspects of the context the expression depends on.
NodeInfo
getNode(Context context)
Return the node selected by this expression.
Expression
reduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

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

enumerate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsString, getNode, isContextDocumentNodeSet, selectFirst

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

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

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

containsReferences, display, enumerate, evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getDependencies, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, reduce, setStaticContext, simplify, usesCurrent

Method Details

display

public void display(int level)
Diagnostic print of expression structure
Overrides:
display in interface Expression

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
Overrides:
getDependencies in interface Expression

getNode

public NodeInfo getNode(Context context)
            throws XPathException
Return the node selected by this expression.
Overrides:
getNode in interface SingletonExpression
Parameters:
context - The context for the evaluation
Returns:
one NodeInfo only, namely the current node defined by the context

reduce

public Expression reduce(int dependencies,
                         Context context)
            throws XPathException
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Overrides:
reduce in interface 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