## 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.