com.rabbitmq.jms.parse.TokenStream Maven / Gradle / Ivy
/* Copyright (c) 2013 Pivotal Software, Inc. All rights reserved. */
/**
* A stream of tokens. Supports getNextToken() and putBackToken() operations as well as moreTokens().
*/
package com.rabbitmq.jms.parse;
/**
* A read-only sequence of {@link Token}s that are read one-by-one. Reads are not destructive and the stream can be reset and reread.
* At any time a position may be obtained, and subsequently used to reset the stream to that position.
*
* @param - the type of items in the stream
* @param - the type which implements the positions in the stream
*/
public interface TokenStream {
/**
* @return true if there are more tokens after the current position in the stream
*/
boolean moreTokens();
/**
* Reads token at the current position and the position is not changed.
* @return the current {@link Token} in the stream if any, otherwise null
*/
Token readToken();
/**
* Increment position in the stream; no-op if already at the end.
* @return the next {@link Token} in the stream if any, otherwise null
*/
Token getNext();
/**
* Decrement position in the stream; no-op if already at the beginning.
*/
void stepBack();
/**
* @return the current position in the stream
*/
Position position();
/**
* Reset the stream to the position provided, if it is a valid position. Otherwise undefined.
* @param position - previously returned place in the stream
*/
void reset(Position position);
/**
* Reset the stream to the start. Equivalent to
* tokenStream.reset(START) where Position START = tokenStream.getPosition();
* was executed first after instantiation of the {@link TokenStream}.
*/
void reset();
}