Class Token

java.lang.Object

Token

public class Token
extends java.lang.Object

A Token class in which tokens know whether they are operators or numbers and can return appropriate values. If a token cannot be created from the string, an IllegalArgumentException is thrown. The legal operators are + - * / ( )

Author:

Beth Katz

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	OperatorList

Constructor Summary

Constructors

Constructor and Description
Token(java.lang.Double d) Build a number Token from a Double.
Token(java.lang.String s) Build a Token from a String.

Method Summary

Modifier and Type	Method and Description
boolean	hasHigherPrecedenceThan(Token other) Whether or not the Token has higher precedence than other Token
boolean	isLeftParen() Whether or not the Token is a left parentheses.
boolean	isNumber() Whether or not the Token is a number.
boolean	isOperator() Whether or not the Token is an operator.
boolean	isRightParen() Whether or not the Token is a right parentheses.
java.lang.Double	numberValue() The numeric value of the Token if it is a number Token Throws IllegalArgumentException if Token is not a number
java.lang.Character	operatorCharValue() The character value of the Token if it is an operator Token Throws IllegalArgumentException if Token is not an operator
java.lang.String	toString() String representation of the Token

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

OperatorList

public static final java.lang.String OperatorList

See Also:

Constant Field Values

Constructor Detail

Token

public Token(java.lang.String s)

Build a Token from a String. This can build number Tokens.

Parameters:

s - String containing a potential Token. Will throw IllegalArgumentException if Token cannot be built.

Token

public Token(java.lang.Double d)

Build a number Token from a Double.

Parameters:

s - Double containing a Token.

Method Detail

isNumber

public boolean isNumber()

Whether or not the Token is a number.

Returns:

true if Token is a number, false if not

isOperator

public boolean isOperator()

Whether or not the Token is an operator. Parentheses are not operators.

Returns:

true if Token is a operator, false if not

isLeftParen

public boolean isLeftParen()

Whether or not the Token is a left parentheses.

Returns:

true if Token is a left parentheses, false if not

isRightParen

public boolean isRightParen()

Whether or not the Token is a right parentheses.

Returns:

true if Token is a right parentheses, false if not

hasHigherPrecedenceThan

public boolean hasHigherPrecedenceThan(Token other)

Whether or not the Token has higher precedence than other Token

Returns:

true if Token has higher precedence, false if not

numberValue

public java.lang.Double numberValue()

The numeric value of the Token if it is a number Token Throws IllegalArgumentException if Token is not a number

Returns:

Token's Double value

operatorCharValue

public java.lang.Character operatorCharValue()

The character value of the Token if it is an operator Token Throws IllegalArgumentException if Token is not an operator

Returns:

Token's char value

toString

public java.lang.String toString()

String representation of the Token

Overrides:

toString in class java.lang.Object