org.apache.xpath.operations
Class UnaryOperation

java.lang.Object
  |
  +--org.apache.xpath.Expression
        |
        +--org.apache.xpath.operations.UnaryOperation
Direct Known Subclasses:
Bool, Neg, Number, String

public abstract class UnaryOperation
extends Expression
implements ExpressionOwner

The unary operation base class.

See Also:
Serialized Form

Constructor Summary
UnaryOperation()
           
 
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, error, execute, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isStableNumber, num, warn, xstr
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

UnaryOperation

public UnaryOperation()
Method Detail

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.
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).
Overrides:
fixupVariables in class Expression

canTraverseOutsideSubtree

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

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.
Parameters:
xctxt - The runtime execution context.
Returns:
An XObject that represents the result of applying the unary operation to the evaluated operand.
Throws:
TransformerException -  
Overrides:
execute in class Expression

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)
See Also:
XPathVisitable.callVisitors(ExpressionOwner, XPathVisitor)

getExpression

public Expression getExpression()
Specified by:
getExpression in interface ExpressionOwner
See Also:
ExpressionOwner.getExpression()

setExpression

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

deepEquals

public boolean deepEquals(Expression expr)
Overrides:
deepEquals in class Expression
See Also:
Expression.deepEquals(Expression)


Copyright 2006 Apache XML Project. All Rights Reserved.