net.sourceforge.czt.parser.util
Class TokenStack

java.lang.Object
  net.sourceforge.czt.parser.util.TokenStack

public class TokenStack
extends java.lang.Object

A stack of tokens that is initialised with the tokens provided by a scanner. A scanner that returns a stream of tokens can be seen as an iterator, or a stack without #push method. This class provides a stack view of a scanner that allows pushing tokens back into the token stream. When initialised with a scanner, the stack contains all the tokens provided by the scanner. They are returned via the #pop method. In addition, it is possible to push tokens back into the stream. This allows, for instance, lookahead and eases the manipulation of token streams.

Author:

Petra Malik

Constructor Summary

TokenStack(net.sourceforge.czt.java_cup.runtime.Scanner scanner)

Method Summary

net.sourceforge.czt.java_cup.runtime.Symbol	pop()
void	push(net.sourceforge.czt.java_cup.runtime.Symbol symbol)

Methods inherited from class java.lang.Object

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

Constructor Detail

TokenStack

public TokenStack(net.sourceforge.czt.java_cup.runtime.Scanner scanner)

Method Detail

pop

public net.sourceforge.czt.java_cup.runtime.Symbol pop()
                                                throws java.lang.Exception

Throws:

java.lang.Exception

push

public void push(net.sourceforge.czt.java_cup.runtime.Symbol symbol)