Opus5
Class ExpressionTree

java.lang.Object
  |
  +--Opus5.AbstractObject
        |
        +--Opus5.AbstractContainer
              |
              +--Opus5.AbstractTree
                    |
                    +--Opus5.BinaryTree
                          |
                          +--Opus5.ExpressionTree

All Implemented Interfaces:

Comparable, Container, Tree

public class ExpressionTree

extends BinaryTree

Represents a binary expression as a binary tree.

Version:

$Id: ExpressionTree.java,v 3.1 1998/07/28 01:32:17 brpreiss Exp $

Author:

Bruno R. Preiss, P.Eng.

Inner classes inherited from class Opus5.AbstractTree

AbstractTree.TreeEnumeration

Fields inherited from class Opus5.BinaryTree

key, left, right

Fields inherited from class Opus5.AbstractContainer

count

Fields inherited from interface Opus5.Tree

copyright

Constructor Summary

ExpressionTree(char c)
Constructs a ExpressionTree that consists of a single (leaf) node with the specified label.

Method Summary

static ExpressionTree	parsePostfix(java.io.Reader in) Parses a postfix expression read from the specified input stream and constructs the corresponding expression tree.
java.lang.String	toString() Returns a string representation of this expression tree using infix notation.

Methods inherited from class Opus5.BinaryTree

attachKey, attachLeft, attachRight, compareTo, depthFirstTraversal, detachKey, detachLeft, detachRight, getDegree, getKey, getLeft, getRight, getSubtree, isEmpty, isLeaf, purge

Methods inherited from class Opus5.AbstractTree

accept, breadthFirstTraversal, getCount, getEnumeration, getHeight

Methods inherited from class Opus5.AbstractContainer

hashCode, isFull

Methods inherited from class Opus5.AbstractObject

compare, equals, isEQ, isGE, isGT, isLE, isLT, isNE

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Opus5.Container

isFull

Methods inherited from interface Opus5.Comparable

compare, isEQ, isGE, isGT, isLE, isLT, isNE

Constructor Detail

ExpressionTree

public ExpressionTree(char c)

Constructs a ExpressionTree that consists of a single (leaf) node with the specified label.

Parameters:

c - The label on this node.

Method Detail

parsePostfix

public static ExpressionTree parsePostfix(java.io.Reader in)
                                   throws java.io.IOException

Parses a postfix expression read from the specified input stream and constructs the corresponding expression tree. The postfix expression consists of one-letter symbols, one-digit numbers, +, -, * and /.

Parameters:

in - The input stream.

Returns:

An expression tree.

Throws:

java.io.IOException - If an error occurs while reading input.

toString

public java.lang.String toString()

Returns a string representation of this expression tree using infix notation.

Overrides:

toString in class AbstractContainer

Returns:

A string representation of this expression tree.