infixexpression

Class InfixTokenizer

java.lang.Object

infixexpression.InfixTokenizer

public class InfixTokenizer
extends java.lang.Object

This class is used to tokenize an infix string. The input string is scanned from left to right. The tokens are discovered and a Token object is created for each token. An array is used to hold the list of tokens.

Constructor Summary

Constructors

Constructor and Description
InfixTokenizer(java.lang.String line)

Method Summary

Modifier and Type	Method and Description
int	getSize()
Token[]	getTokens()
boolean	isDecimalPoint(char ch)
boolean	isDigit(char ch)
boolean	isLeftParen(char ch)
boolean	isLetter(char ch)
boolean	isRightParen(char ch)
static void	main(java.lang.String[] args) Test drive the InfixTokenizer.
boolean	operator(char ch)
Token[]	parseLine() parses the line and creates an array of Tokens.

Methods inherited from class java.lang.Object

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

Constructor Detail

InfixTokenizer

public InfixTokenizer(java.lang.String line)

Parameters:

line - is a string in proper infix form.

Method Detail

getSize

public int getSize()

Returns:

size of the array of tokens

getTokens

public Token[] getTokens()

Returns:

an array of Tokens

operator

public boolean operator(char ch)

Parameters:

ch -

Returns:

true is ch is in the set { +,-,/,*, ^, =}

isLetter

public boolean isLetter(char ch)

Parameters:

ch -

Returns:

true if ch is a letter

isDigit

public boolean isDigit(char ch)

Parameters:

ch -

Returns:

true if ch is a digit

isDecimalPoint

public boolean isDecimalPoint(char ch)

Parameters:

ch -

Returns:

true if ch is decimal point

isLeftParen

public boolean isLeftParen(char ch)

Parameters:

ch -

Returns:

true if ch is (

isRightParen

public boolean isRightParen(char ch)

Parameters:

ch -

Returns:

true if ch is )

parseLine

public Token[] parseLine()

parses the line and creates an array of Tokens. This method does not use StringTokenizer or split to perform its work.

Returns:

array of tokens

main

public static void main(java.lang.String[] args)

Test drive the InfixTokenizer.

Parameters:

args -