/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package java.lang;

import java.io.IOException;
import java.nio.CharBuffer;

/**
 * Readable marks that the implementing class provides character sequence.
 * Readable gives a reference to character sequence from within itself to caller
 * through a <code>CharBuffer</code> parameter of the <code>read</code>
 * method.
 */
public interface Readable {

	/**
	 * Reads the characters into the given <code>CharBuffer</code>. The
	 * maximum number of characters read is <code>CharBuffer.remaining()</code>.
	 * 
	 * @param cb
	 *            the buffer to be filled in by the characters read
	 * @return the number of characters actually read, or -1 if this
	 *         <code>Readable</code> reaches its end
	 * @throws IOException
	 *             if some I/O operations fail
	 */
	int read(CharBuffer cb) throws IOException;
}
