Class TokenScanner

java.lang.Object

TokenScanner

public class TokenScanner
extends java.lang.Object

A "scanner" for Tokens that doesn't need to have whitespace separated Tokens. There are no delimiters. Recognizes the operators from Token.OperatorList. These are all operators from Token including parentheses. Recognizes simple non-negative real numbers with or without a decimal point. Must have digits on both sides of the decimal point if there is one. Does not recognize negative numbers. Will tokenize them as minus and a number. Throws NoSuchElementException if Token is requested but doesn't exist at current location in source. There is no error recovery or peek.

Version:

March 2008

Author:

Beth Katz

Constructor Summary

Constructors

Constructor and Description
TokenScanner(java.lang.String s) Constructs a TokenScanner from a String

Method Summary

Modifier and Type	Method and Description
boolean	hasNextToken() Whether or not there is a Token available.
Token	nextToken() Provides the next Token from source.
boolean	reachedEnd() Returns whether or not entire source was tokenized.

Methods inherited from class java.lang.Object

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

Constructor Detail

TokenScanner

public TokenScanner(java.lang.String s)

Constructs a TokenScanner from a String

Method Detail

hasNextToken

public boolean hasNextToken()

Whether or not there is a Token available.

Returns:

true if there is a Token available, false if not

nextToken

public Token nextToken()

Provides the next Token from source. Throws NoSuchElementException if there is no Token.

Returns:

next Token

reachedEnd

public boolean reachedEnd()

Returns whether or not entire source was tokenized.

Returns:

true if all of source has been tokenized and there is no more data, false if not