org.apache.xpath.operations

Class UnaryOperation

Implemented Interfaces:
ExpressionNode, ExpressionOwner, java.io.Serializable, SourceLocator, XPathVisitable
Known Direct Subclasses:
Bool, Neg, Number, String

public abstract class UnaryOperation
extends Expression
implements ExpressionOwner

The unary operation base class.
See Also:
Serialized Form

Method Summary

void
callVisitors(ExpressionOwner owner, XPathVisitor visitor)
boolean
canTraverseOutsideSubtree()
Tell if this expression or it's subexpressions can traverse outside the current subtree.
boolean
deepEquals(Expression expr)
XObject
execute(XPathContext xctxt)
Execute the operand and apply the unary operation to the result.
void
fixupVariables(java.util.Vector vars, int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
Expression
getExpression()
Expression
getOperand()
abstract XObject
operate(XObject right)
Apply the operation to two operands, and return the result.
void
setExpression(Expression exp)
void
setRight(Expression r)
Set the expression operand for the operation.

Methods inherited from class org.apache.xpath.Expression

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

Method Details

callVisitors

public void callVisitors(ExpressionOwner owner,
                         XPathVisitor visitor)
Specified by:
callVisitors in interface XPathVisitable

canTraverseOutsideSubtree

public boolean canTraverseOutsideSubtree()
Tell if this expression or it's subexpressions can traverse outside the current subtree.
Overrides:
canTraverseOutsideSubtree in interface Expression
Returns:
true if traversal outside the context node's subtree can occur.

deepEquals

public boolean deepEquals(Expression expr)
Overrides:
deepEquals in interface Expression

execute

public XObject execute(XPathContext xctxt)
            throws javax.xml.transform.TransformerException
Execute the operand and apply the unary operation to the result.
Overrides:
execute in interface Expression
Parameters:
xctxt - The runtime execution context.
Returns:
An XObject that represents the result of applying the unary operation to the evaluated operand.

fixupVariables

public void fixupVariables(java.util.Vector vars,
                           int globalsSize)
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.
Overrides:
fixupVariables in interface 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).

getExpression

public Expression getExpression()
Specified by:
getExpression in interface ExpressionOwner

getOperand

public Expression getOperand()
Returns:
the operand of unary operation, as an Expression.

operate

public abstract XObject operate(XObject right)
            throws javax.xml.transform.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.

setExpression

public void setExpression(Expression exp)
Specified by:
setExpression in interface ExpressionOwner

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.

Copyright B) 2005 Apache XML Project. All Rights Reserved.