jaroslav@52: /*
jaroslav@52:  * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
jaroslav@52:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@52:  *
jaroslav@52:  * This code is free software; you can redistribute it and/or modify it
jaroslav@52:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@52:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@52:  * particular file as subject to the "Classpath" exception as provided
jaroslav@52:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@52:  *
jaroslav@52:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@52:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@52:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@52:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@52:  * accompanied this code).
jaroslav@52:  *
jaroslav@52:  * You should have received a copy of the GNU General Public License version
jaroslav@52:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@52:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@52:  *
jaroslav@52:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@52:  * or visit www.oracle.com if you need additional information or have any
jaroslav@52:  * questions.
jaroslav@52:  */
jaroslav@52: 
jaroslav@52: package java.lang;
jaroslav@52: 
jaroslav@52: 
jaroslav@52: /**
jaroslav@52:  * A <tt>CharSequence</tt> is a readable sequence of <code>char</code> values. This
jaroslav@52:  * interface provides uniform, read-only access to many different kinds of
jaroslav@52:  * <code>char</code> sequences.
jaroslav@52:  * A <code>char</code> value represents a character in the <i>Basic
jaroslav@52:  * Multilingual Plane (BMP)</i> or a surrogate. Refer to <a
jaroslav@52:  * href="Character.html#unicode">Unicode Character Representation</a> for details.
jaroslav@52:  *
jaroslav@52:  * <p> This interface does not refine the general contracts of the {@link
jaroslav@52:  * java.lang.Object#equals(java.lang.Object) equals} and {@link
jaroslav@52:  * java.lang.Object#hashCode() hashCode} methods.  The result of comparing two
jaroslav@52:  * objects that implement <tt>CharSequence</tt> is therefore, in general,
jaroslav@52:  * undefined.  Each object may be implemented by a different class, and there
jaroslav@52:  * is no guarantee that each class will be capable of testing its instances
jaroslav@52:  * for equality with those of the other.  It is therefore inappropriate to use
jaroslav@52:  * arbitrary <tt>CharSequence</tt> instances as elements in a set or as keys in
jaroslav@52:  * a map. </p>
jaroslav@52:  *
jaroslav@52:  * @author Mike McCloskey
jaroslav@52:  * @since 1.4
jaroslav@52:  * @spec JSR-51
jaroslav@52:  */
jaroslav@52: 
jaroslav@52: public interface CharSequence {
jaroslav@52: 
jaroslav@52:     /**
jaroslav@52:      * Returns the length of this character sequence.  The length is the number
jaroslav@52:      * of 16-bit <code>char</code>s in the sequence.</p>
jaroslav@52:      *
jaroslav@52:      * @return  the number of <code>char</code>s in this sequence
jaroslav@52:      */
jaroslav@52:     int length();
jaroslav@52: 
jaroslav@52:     /**
jaroslav@52:      * Returns the <code>char</code> value at the specified index.  An index ranges from zero
jaroslav@52:      * to <tt>length() - 1</tt>.  The first <code>char</code> value of the sequence is at
jaroslav@52:      * index zero, the next at index one, and so on, as for array
jaroslav@52:      * indexing. </p>
jaroslav@52:      *
jaroslav@52:      * <p>If the <code>char</code> value specified by the index is a
jaroslav@52:      * <a href="{@docRoot}/java/lang/Character.html#unicode">surrogate</a>, the surrogate
jaroslav@52:      * value is returned.
jaroslav@52:      *
jaroslav@52:      * @param   index   the index of the <code>char</code> value to be returned
jaroslav@52:      *
jaroslav@52:      * @return  the specified <code>char</code> value
jaroslav@52:      *
jaroslav@52:      * @throws  IndexOutOfBoundsException
jaroslav@52:      *          if the <tt>index</tt> argument is negative or not less than
jaroslav@52:      *          <tt>length()</tt>
jaroslav@52:      */
jaroslav@52:     char charAt(int index);
jaroslav@52: 
jaroslav@52:     /**
jaroslav@52:      * Returns a new <code>CharSequence</code> that is a subsequence of this sequence.
jaroslav@52:      * The subsequence starts with the <code>char</code> value at the specified index and
jaroslav@52:      * ends with the <code>char</code> value at index <tt>end - 1</tt>.  The length
jaroslav@52:      * (in <code>char</code>s) of the
jaroslav@52:      * returned sequence is <tt>end - start</tt>, so if <tt>start == end</tt>
jaroslav@52:      * then an empty sequence is returned. </p>
jaroslav@52:      *
jaroslav@52:      * @param   start   the start index, inclusive
jaroslav@52:      * @param   end     the end index, exclusive
jaroslav@52:      *
jaroslav@52:      * @return  the specified subsequence
jaroslav@52:      *
jaroslav@52:      * @throws  IndexOutOfBoundsException
jaroslav@52:      *          if <tt>start</tt> or <tt>end</tt> are negative,
jaroslav@52:      *          if <tt>end</tt> is greater than <tt>length()</tt>,
jaroslav@52:      *          or if <tt>start</tt> is greater than <tt>end</tt>
jaroslav@52:      */
jaroslav@52:     CharSequence subSequence(int start, int end);
jaroslav@52: 
jaroslav@52:     /**
jaroslav@52:      * Returns a string containing the characters in this sequence in the same
jaroslav@52:      * order as this sequence.  The length of the string will be the length of
jaroslav@52:      * this sequence. </p>
jaroslav@52:      *
jaroslav@52:      * @return  a string consisting of exactly this sequence of characters
jaroslav@52:      */
jaroslav@52:     public String toString();
jaroslav@52: 
jaroslav@52: }