java.lang.Object
- org.apache.xpath.Expression
- - org.apache.xpath.operations.Operation

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, ExpressionNode, ExpressionOwner, XPathVisitable

Direct Known Subclasses:

And, Div, Equals, Gt, Gte, Lt, Lte, Minus, Mod, Mult, NotEquals, Or, Plus, Quo
```
public class Operation
extends Expression
implements ExpressionOwner
```
The baseclass for a binary operation.

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor Description

Operation()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	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 a binary operation by calling execute on each of the operands, and then calling the operate method on the derived class.
`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()`	Get the raw Expression object that this class wraps.
`Expression`	`getLeftOperand()`
`Expression`	`getRightOperand()`
`XObject`	`operate(XObject left, 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`	`setLeftRight(Expression l, Expression r)`	Set the left and right operand expressions for this 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
  - Operation
```
public Operation()
```
- 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.
    
    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.
  - setLeftRight
```
public void setLeftRight(Expression l,
                         Expression r)
```
    Set the left and right operand expressions for this operation.
    
    Parameters:
    
    l - The left expression operand.
    
    r - The right expression operand.
  - execute
```
public XObject execute(XPathContext xctxt)
                throws javax.xml.transform.TransformerException
```
    Execute a binary operation by calling execute on each of the operands, and then calling the operate method on the derived class.
    
    Specified by:
    
    execute in class Expression
    
    Parameters:
    
    xctxt - The runtime execution context.
    
    Returns:
    
    The XObject result of the operation.
    
    Throws:
    
    javax.xml.transform.TransformerException
  - operate
```
public XObject operate(XObject left,
                       XObject right)
                throws javax.xml.transform.TransformerException
```
    Apply the operation to two operands, and return the result.
    
    Parameters:
    
    left - non-null reference to the evaluated left operand.
    
    right - non-null reference to the evaluated right operand.
    
    Returns:
    
    non-null reference to the XObject that represents the result of the operation.
    
    Throws:
    
    javax.xml.transform.TransformerException
  - getLeftOperand
```
public Expression getLeftOperand()
```
    Returns:
    
    the left operand of binary operation, as an Expression.
  - getRightOperand
```
public Expression getRightOperand()
```
    Returns:
    
    the right operand of binary 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)

Class Operation

Constructor Summary

Method Summary

Methods inherited from class org.apache.xpath.Expression

Methods inherited from class java.lang.Object

Constructor Detail

Operation

Method Detail

fixupVariables

canTraverseOutsideSubtree

setLeftRight

execute

operate

getLeftOperand

getRightOperand

callVisitors

getExpression

setExpression

deepEquals