rp.expn
Class OperatorExpn

java.lang.Object
  |
  +--java.util.Observable
        |
        +--rp.expn.Expn
              |
              +--rp.expn.OperatorExpn

All Implemented Interfaces:

java.util.Observer

Direct Known Subclasses:

BinaryOperatorExpn, NaryOperatorExpn, UnaryOperatorExpn

public abstract class OperatorExpn

extends Expn

implements java.util.Observer

A generic node in an expression tree.

Version:

$Revision: 1.2 $, $Date: 2001/05/23 19:26:22 $

Field Summary

protected java.util.Vector

operands

Constructor Summary

OperatorExpn()

Method Summary

int	getNumOperands() Gets the number of operands for this operator.
Expn[]	getOperand() Gets all the operands at once.
Expn	getOperand(int i) Gets the i'th operand (0-based) of this operator.
protected void	setNumOperands(int n) Sets the number of operands for this operator.
protected void	setOperand(Expn[] newOperands) Sets all the operands at once Either this method or setNumOperands must be called before any other
protected void	setOperand(int i, Expn newOperand) Sets the i'th operand (0-based) to the given expression.
void	update(java.util.Observable o, java.lang.Object arg)

Methods inherited from class rp.expn.Expn

getScalarMean

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Field Detail

operands

protected java.util.Vector operands

Constructor Detail

OperatorExpn

public OperatorExpn()

Method Detail

update

public void update(java.util.Observable o,
                   java.lang.Object arg)

Specified by:

update in interface java.util.Observer

setNumOperands

protected void setNumOperands(int n)

Sets the number of operands for this operator. Either this method or setOperand(Expn[]) must be called before any other.

Parameters:

n - the number of operands

getNumOperands

public int getNumOperands()

Gets the number of operands for this operator.

Returns:

the number of operands

setOperand

protected void setOperand(int i,
                          Expn newOperand)

Sets the i'th operand (0-based) to the given expression. If the expression is null, cleanly removes the previous i'th operand.

Parameters:

i - the index (0-based) of the operand to set

setOperand

protected void setOperand(Expn[] newOperands)

Sets all the operands at once Either this method or setNumOperands must be called before any other

getOperand

public Expn getOperand(int i)

Gets the i'th operand (0-based) of this operator.

Parameters:

i - the index (0-based) of the operand to get

Returns:

the i'th operand

getOperand

public Expn[] getOperand()

Gets all the operands at once.

Returns:

an aray containing all the operands