org.apache.xpath.operations

Class UnaryOperation

java.lang.Object

org.apache.xpath.Expression

org.apache.xpath.operations.UnaryOperation

All Implemented Interfaces:

Serializable, SourceLocator, ExpressionNode, ExpressionOwner, XPathVisitable

Direct Known Subclasses:

Bool, Neg, Number, String

public abstract class UnaryOperation
extends Expression
implements ExpressionOwner

The unary operation base class.

See Also:

Serialized Form

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
UnaryOperation()

Method Summary

Modifier and Type	Method and Description
void	callVisitors(ExpressionOwner owner, XPathVisitor visitor) This will traverse the heararchy, 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 the operand and apply the unary operation to the result.
void	fixupVariables(Vector vars, int globalsSize) This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
Expression	getExpression() Get the raw Expression object that this class wraps.
Expression	getOperand()
abstract XObject	operate(XObject right) Apply the operation to two operands, and return the result.
void	setExpression(Expression exp) Set the raw expression object for this object.
void	setRight(Expression r) Set the expression operand for the operation.

Methods inherited from class org.apache.xpath.Expression

asIterator, asIteratorRaw, asNode, assertion, bool, error, execute, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isSameClass, isStableNumber, num, warn, xstr

Methods inherited from class java.lang.Object

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

Field Detail

m_right

protected Expression m_right

The operand for the operation.

Constructor Detail

UnaryOperation

public UnaryOperation()

Method Detail

fixupVariables

public void fixupVariables(Vector vars,
                           int globalsSize)

This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.

Specified by:

fixupVariables in class Expression

Parameters:

vars - List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).

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 the operand and apply the unary operation to the result.

Specified by:

execute in class Expression

Parameters:

xctxt - The runtime execution context.

Returns:

An XObject that represents the result of applying the unary operation to the evaluated operand.

Throws:

TransformerException

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

getOperand

public Expression getOperand()

Returns:

the operand of unary operation, as an Expression.

callVisitors

public void callVisitors(ExpressionOwner owner,
                         XPathVisitor visitor)

Description copied from interface: XPathVisitable

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

Specified by:

callVisitors in interface XPathVisitable

Parameters:

owner - The owner of the visitor, where that path may be rewritten if needed.

visitor - The visitor whose appropriate method will be called.

See Also:

XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)

getExpression

public Expression getExpression()

Description copied from interface: ExpressionOwner

Get the raw Expression object that this class wraps.

Specified by:

getExpression in interface ExpressionOwner

Returns:

the raw Expression object, which should not normally be null.

See Also:

ExpressionOwner.getExpression()

setExpression

public void setExpression(Expression exp)

Description copied from interface: ExpressionOwner

Set the raw expression object for this object.

Specified by:

setExpression in interface ExpressionOwner

Parameters:

exp - the raw Expression object, which should not normally be null.

See Also:

ExpressionOwner.setExpression(Expression)

deepEquals

public boolean deepEquals(Expression expr)

Description copied from class: Expression

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.

See Also:

Expression.deepEquals(Expression)