package it.unimi.dsi.compression;
/*
* DSI utilities
*
* Copyright (C) 2005-2009 Sebastiano Vigna
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 2.1 of the License, or (at your option)
* any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
import it.unimi.dsi.fastutil.booleans.BooleanIterator;
import it.unimi.dsi.io.OutputBitStream;
import java.io.IOException;
/** Coding methods for a specific compression technique. */
public interface Coder {
/** Encodes a symbol.
*
* @param symbol a symbol.
* @return a boolean iterator returning the bits coding <code>symbol</code>.
*/
BooleanIterator encode( int symbol );
/** Encodes a symbol.
*
* @param symbol a symbol.
* @param obs the output bit stream where the encoded symbol will be written.
* @return the number of bits written.
*/
int encode( int symbol, OutputBitStream obs ) throws IOException;
/** Flushes the coder.
*
* <strong>Warning</strong>: this method will <em>not</em> {@link OutputBitStream#flush() flush} <code>obs</code>.
*
* @param obs the output bit stream where the flushing bits will be written.
* @return the number of bits written to flush the coder.
*/
int flush( OutputBitStream obs );
/** Flushes the coder.
*
* @return a boolean iterator returning the bits used to flush this coder.
*/
BooleanIterator flush();
}