com.icl.saxon.expr

Class ParentNodeExpression


public class ParentNodeExpression
extends SingletonExpression

Class ParentNodeExpression represents the XPath expression ".." or "parent::node()"

Field Summary

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

staticContext

Method Summary

void
display(int level)
Diagnostic print of expression structure
boolean
evaluateAsBoolean(Context context)
Evaluate as a boolean.
String
evaluateAsString(Context context)
Evaluate as a string.
int
getDependencies()
Determine which aspects of the context the expression depends on.
NodeInfo
getNode(Context context)
Return the node selected by this SingletonExpression
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


evaluateAsBoolean

public boolean evaluateAsBoolean(Context context)
            throws XPathException
Evaluate as a boolean. Returns true if there are any nodes selected by the NodeSetExpression.
Overrides:
evaluateAsBoolean in interface SingletonExpression

Parameters:
context - The context in which the expression is to be evaluated

Returns:
true unless the current node is the Document node


evaluateAsString

public String evaluateAsString(Context context)
            throws XPathException
Evaluate as a string. Returns the string value of the parent node
Overrides:
evaluateAsString in interface SingletonExpression

Parameters:
context - The context in which the expression is to be evaluated

Returns:
the value of the current node, identified by the context


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 SingletonExpression
Overrides:
getNode in interface SingletonExpression

Parameters:
context - The context for the evaluation

Returns:
the parent of 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