Package org.loboevolution.apache.xpath.operations

Class UnaryOperation

java.lang.Object

org.loboevolution.apache.xpath.Expression

org.loboevolution.apache.xpath.operations.UnaryOperation

All Implemented Interfaces:

SourceLocator, ExpressionNode, XPathVisitable

Direct Known Subclasses:

Bool, Neg, Number, String

public abstract class UnaryOperation
extends Expression

The unary operation base class.

Field Summary

Fields

Modifier and Type	Field	Description
protected Expression	m_right	The operand for the operation.

Constructor Summary

Constructors

Constructor	Description
UnaryOperation()

Method Summary

Modifier and Type	Method	Description
void	callVisitors(XPathVisitor visitor)	This will traverse the hierarchy, calling the visitor for each member.
boolean	canTraverseOutsideSubtree()	Tell if this expression or it's subexpressions can traverse outside the current subtree.
boolean	deepEquals(Expression expr)	Compare this object with another object and see if they are equal, include the sub heararchy.
XObject	execute(XPathContext xctxt)	Execute an expression in the XPath runtime context, and return the result of the expression.
abstract XObject	operate(XObject right)	Apply the operation to two operands, and return the result.
void	setRight(Expression r)	Set the expression operand for the operation.

Methods inherited from class org.loboevolution.apache.xpath.Expression

asIterator, asNode, assertion, bool, error, execute, execute, execute, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isSameClass, isStableNumber, num

Methods inherited from class java.lang.Object

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

Field Details

m_right

protected Expression m_right

The operand for the operation.

Constructor Details

UnaryOperation

public UnaryOperation()

Method Details

canTraverseOutsideSubtree

public boolean canTraverseOutsideSubtree()

Tell if this expression or it's subexpressions can traverse outside the current subtree.

Overrides:

canTraverseOutsideSubtree in class Expression

Returns:

true if traversal outside the context node's subtree can occur.

setRight

public void setRight(Expression r)

Set the expression operand for the operation.

Parameters:

r - The expression operand to which the unary operation will be applied.

execute

public XObject execute(XPathContext xctxt)
                throws TransformerException

Execute an expression in the XPath runtime context, and return the result of the expression.

Specified by:

execute in class Expression

Parameters:

xctxt - The XPath runtime context.

Returns:

The result of the expression in the form of a XObject.

Throws:

TransformerException - if a runtime exception occurs.

operate

public abstract XObject operate(XObject right)
                         throws TransformerException

Apply the operation to two operands, and return the result.

Parameters:

right - non-null reference to the evaluated right operand.

Returns:

non-null reference to the XObject that represents the result of the operation.

Throws:

TransformerException - in case of error

callVisitors

public void callVisitors(XPathVisitor visitor)

This will traverse the hierarchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.

Parameters:

visitor - The visitor whose appropriate method will be called.

deepEquals

public boolean deepEquals(Expression expr)

Compare this object with another object and see if they are equal, include the sub heararchy.

Specified by:

deepEquals in class Expression

Parameters:

expr - Another expression object.

Returns:

true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.