emul/mini/src/main/java/java/lang/String.java
author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
Thu, 24 Jan 2013 18:03:29 +0100
branchemul
changeset 573 d3a0383d01d3
parent 572 emul/src/main/java/java/lang/String.java@e84419744dba
parent 560 emul/src/main/java/java/lang/String.java@53fafe384803
child 592 5e13b1ac2886
permissions -rw-r--r--
Merging essential operations from default branch
     1 /*
     2  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     8  * particular file as subject to the "Classpath" exception as provided
     9  * by Oracle in the LICENSE file that accompanied this code.
    10  *
    11  * This code is distributed in the hope that it will be useful, but WITHOUT
    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    14  * version 2 for more details (a copy is included in the LICENSE file that
    15  * accompanied this code).
    16  *
    17  * You should have received a copy of the GNU General Public License version
    18  * 2 along with this work; if not, write to the Free Software Foundation,
    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    20  *
    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    22  * or visit www.oracle.com if you need additional information or have any
    23  * questions.
    24  */
    25 
    26 package java.lang;
    27 
    28 import java.util.Comparator;
    29 import org.apidesign.bck2brwsr.core.ExtraJavaScript;
    30 import org.apidesign.bck2brwsr.core.JavaScriptBody;
    31 import org.apidesign.bck2brwsr.core.JavaScriptOnly;
    32 import org.apidesign.bck2brwsr.core.JavaScriptPrototype;
    33 import org.apidesign.bck2brwsr.emul.lang.System;
    34 
    35 /**
    36  * The <code>String</code> class represents character strings. All
    37  * string literals in Java programs, such as <code>"abc"</code>, are
    38  * implemented as instances of this class.
    39  * <p>
    40  * Strings are constant; their values cannot be changed after they
    41  * are created. String buffers support mutable strings.
    42  * Because String objects are immutable they can be shared. For example:
    43  * <p><blockquote><pre>
    44  *     String str = "abc";
    45  * </pre></blockquote><p>
    46  * is equivalent to:
    47  * <p><blockquote><pre>
    48  *     char data[] = {'a', 'b', 'c'};
    49  *     String str = new String(data);
    50  * </pre></blockquote><p>
    51  * Here are some more examples of how strings can be used:
    52  * <p><blockquote><pre>
    53  *     System.out.println("abc");
    54  *     String cde = "cde";
    55  *     System.out.println("abc" + cde);
    56  *     String c = "abc".substring(2,3);
    57  *     String d = cde.substring(1, 2);
    58  * </pre></blockquote>
    59  * <p>
    60  * The class <code>String</code> includes methods for examining
    61  * individual characters of the sequence, for comparing strings, for
    62  * searching strings, for extracting substrings, and for creating a
    63  * copy of a string with all characters translated to uppercase or to
    64  * lowercase. Case mapping is based on the Unicode Standard version
    65  * specified by the {@link java.lang.Character Character} class.
    66  * <p>
    67  * The Java language provides special support for the string
    68  * concatenation operator (&nbsp;+&nbsp;), and for conversion of
    69  * other objects to strings. String concatenation is implemented
    70  * through the <code>StringBuilder</code>(or <code>StringBuffer</code>)
    71  * class and its <code>append</code> method.
    72  * String conversions are implemented through the method
    73  * <code>toString</code>, defined by <code>Object</code> and
    74  * inherited by all classes in Java. For additional information on
    75  * string concatenation and conversion, see Gosling, Joy, and Steele,
    76  * <i>The Java Language Specification</i>.
    77  *
    78  * <p> Unless otherwise noted, passing a <tt>null</tt> argument to a constructor
    79  * or method in this class will cause a {@link NullPointerException} to be
    80  * thrown.
    81  *
    82  * <p>A <code>String</code> represents a string in the UTF-16 format
    83  * in which <em>supplementary characters</em> are represented by <em>surrogate
    84  * pairs</em> (see the section <a href="Character.html#unicode">Unicode
    85  * Character Representations</a> in the <code>Character</code> class for
    86  * more information).
    87  * Index values refer to <code>char</code> code units, so a supplementary
    88  * character uses two positions in a <code>String</code>.
    89  * <p>The <code>String</code> class provides methods for dealing with
    90  * Unicode code points (i.e., characters), in addition to those for
    91  * dealing with Unicode code units (i.e., <code>char</code> values).
    92  *
    93  * @author  Lee Boynton
    94  * @author  Arthur van Hoff
    95  * @author  Martin Buchholz
    96  * @author  Ulf Zibis
    97  * @see     java.lang.Object#toString()
    98  * @see     java.lang.StringBuffer
    99  * @see     java.lang.StringBuilder
   100  * @see     java.nio.charset.Charset
   101  * @since   JDK1.0
   102  */
   103 
   104 @ExtraJavaScript(
   105     resource="/org/apidesign/vm4brwsr/emul/lang/java_lang_String.js",
   106     processByteCode=true
   107 )
   108 @JavaScriptPrototype(container = "String.prototype", prototype = "new String")
   109 public final class String
   110     implements java.io.Serializable, Comparable<String>, CharSequence
   111 {
   112     /** real string to delegate to */
   113     private Object r;
   114 
   115     /** use serialVersionUID from JDK 1.0.2 for interoperability */
   116     private static final long serialVersionUID = -6849794470754667710L;
   117     
   118     @JavaScriptOnly(name="toString", value="function() { return this.fld_r; }")
   119     private static void jsToString() {
   120     }
   121     
   122     @JavaScriptOnly(name="valueOf", value="function() { return this.toString().valueOf(); }")
   123     private static void jsValudOf() {
   124     }
   125 
   126     /**
   127      * Class String is special cased within the Serialization Stream Protocol.
   128      *
   129      * A String instance is written initially into an ObjectOutputStream in the
   130      * following format:
   131      * <pre>
   132      *      <code>TC_STRING</code> (utf String)
   133      * </pre>
   134      * The String is written by method <code>DataOutput.writeUTF</code>.
   135      * A new handle is generated to  refer to all future references to the
   136      * string instance within the stream.
   137      */
   138 //    private static final ObjectStreamField[] serialPersistentFields =
   139 //        new ObjectStreamField[0];
   140 
   141     /**
   142      * Initializes a newly created {@code String} object so that it represents
   143      * an empty character sequence.  Note that use of this constructor is
   144      * unnecessary since Strings are immutable.
   145      */
   146     public String() {
   147         this.r = "";
   148     }
   149 
   150     /**
   151      * Initializes a newly created {@code String} object so that it represents
   152      * the same sequence of characters as the argument; in other words, the
   153      * newly created string is a copy of the argument string. Unless an
   154      * explicit copy of {@code original} is needed, use of this constructor is
   155      * unnecessary since Strings are immutable.
   156      *
   157      * @param  original
   158      *         A {@code String}
   159      */
   160     public String(String original) {
   161         this.r = original.toString();
   162     }
   163 
   164     /**
   165      * Allocates a new {@code String} so that it represents the sequence of
   166      * characters currently contained in the character array argument. The
   167      * contents of the character array are copied; subsequent modification of
   168      * the character array does not affect the newly created string.
   169      *
   170      * @param  value
   171      *         The initial value of the string
   172      */
   173     @JavaScriptBody(args = { "charArr" }, body=
   174         "for (var i = 0; i < charArr.length; i++) {\n"
   175       + "  if (typeof charArr[i] === 'number') charArr[i] = String.fromCharCode(charArr[i]);\n"
   176       + "}\n"
   177       + "this.fld_r = charArr.join('');\n"
   178     )
   179     public String(char value[]) {
   180     }
   181 
   182     /**
   183      * Allocates a new {@code String} that contains characters from a subarray
   184      * of the character array argument. The {@code offset} argument is the
   185      * index of the first character of the subarray and the {@code count}
   186      * argument specifies the length of the subarray. The contents of the
   187      * subarray are copied; subsequent modification of the character array does
   188      * not affect the newly created string.
   189      *
   190      * @param  value
   191      *         Array that is the source of characters
   192      *
   193      * @param  offset
   194      *         The initial offset
   195      *
   196      * @param  count
   197      *         The length
   198      *
   199      * @throws  IndexOutOfBoundsException
   200      *          If the {@code offset} and {@code count} arguments index
   201      *          characters outside the bounds of the {@code value} array
   202      */
   203     @JavaScriptBody(args = { "charArr", "off", "cnt" }, body =
   204         "var up = off + cnt;\n" +
   205         "for (var i = off; i < up; i++) {\n" +
   206         "  if (typeof charArr[i] === 'number') charArr[i] = String.fromCharCode(charArr[i]);\n" +
   207         "}\n" +
   208         "this.fld_r = charArr.slice(off, up).join(\"\");\n"
   209     )
   210     public String(char value[], int offset, int count) {
   211     }
   212 
   213     /**
   214      * Allocates a new {@code String} that contains characters from a subarray
   215      * of the <a href="Character.html#unicode">Unicode code point</a> array
   216      * argument.  The {@code offset} argument is the index of the first code
   217      * point of the subarray and the {@code count} argument specifies the
   218      * length of the subarray.  The contents of the subarray are converted to
   219      * {@code char}s; subsequent modification of the {@code int} array does not
   220      * affect the newly created string.
   221      *
   222      * @param  codePoints
   223      *         Array that is the source of Unicode code points
   224      *
   225      * @param  offset
   226      *         The initial offset
   227      *
   228      * @param  count
   229      *         The length
   230      *
   231      * @throws  IllegalArgumentException
   232      *          If any invalid Unicode code point is found in {@code
   233      *          codePoints}
   234      *
   235      * @throws  IndexOutOfBoundsException
   236      *          If the {@code offset} and {@code count} arguments index
   237      *          characters outside the bounds of the {@code codePoints} array
   238      *
   239      * @since  1.5
   240      */
   241     public String(int[] codePoints, int offset, int count) {
   242         if (offset < 0) {
   243             throw new StringIndexOutOfBoundsException(offset);
   244         }
   245         if (count < 0) {
   246             throw new StringIndexOutOfBoundsException(count);
   247         }
   248         // Note: offset or count might be near -1>>>1.
   249         if (offset > codePoints.length - count) {
   250             throw new StringIndexOutOfBoundsException(offset + count);
   251         }
   252 
   253         final int end = offset + count;
   254 
   255         // Pass 1: Compute precise size of char[]
   256         int n = count;
   257         for (int i = offset; i < end; i++) {
   258             int c = codePoints[i];
   259             if (Character.isBmpCodePoint(c))
   260                 continue;
   261             else if (Character.isValidCodePoint(c))
   262                 n++;
   263             else throw new IllegalArgumentException(Integer.toString(c));
   264         }
   265 
   266         // Pass 2: Allocate and fill in char[]
   267         final char[] v = new char[n];
   268 
   269         for (int i = offset, j = 0; i < end; i++, j++) {
   270             int c = codePoints[i];
   271             if (Character.isBmpCodePoint(c))
   272                 v[j] = (char) c;
   273             else
   274                 Character.toSurrogates(c, v, j++);
   275         }
   276 
   277         this.r = new String(v, 0, n);
   278     }
   279 
   280     /**
   281      * Allocates a new {@code String} constructed from a subarray of an array
   282      * of 8-bit integer values.
   283      *
   284      * <p> The {@code offset} argument is the index of the first byte of the
   285      * subarray, and the {@code count} argument specifies the length of the
   286      * subarray.
   287      *
   288      * <p> Each {@code byte} in the subarray is converted to a {@code char} as
   289      * specified in the method above.
   290      *
   291      * @deprecated This method does not properly convert bytes into characters.
   292      * As of JDK&nbsp;1.1, the preferred way to do this is via the
   293      * {@code String} constructors that take a {@link
   294      * java.nio.charset.Charset}, charset name, or that use the platform's
   295      * default charset.
   296      *
   297      * @param  ascii
   298      *         The bytes to be converted to characters
   299      *
   300      * @param  hibyte
   301      *         The top 8 bits of each 16-bit Unicode code unit
   302      *
   303      * @param  offset
   304      *         The initial offset
   305      * @param  count
   306      *         The length
   307      *
   308      * @throws  IndexOutOfBoundsException
   309      *          If the {@code offset} or {@code count} argument is invalid
   310      *
   311      * @see  #String(byte[], int)
   312      * @see  #String(byte[], int, int, java.lang.String)
   313      * @see  #String(byte[], int, int, java.nio.charset.Charset)
   314      * @see  #String(byte[], int, int)
   315      * @see  #String(byte[], java.lang.String)
   316      * @see  #String(byte[], java.nio.charset.Charset)
   317      * @see  #String(byte[])
   318      */
   319     @Deprecated
   320     public String(byte ascii[], int hibyte, int offset, int count) {
   321         checkBounds(ascii, offset, count);
   322         char value[] = new char[count];
   323 
   324         if (hibyte == 0) {
   325             for (int i = count ; i-- > 0 ;) {
   326                 value[i] = (char) (ascii[i + offset] & 0xff);
   327             }
   328         } else {
   329             hibyte <<= 8;
   330             for (int i = count ; i-- > 0 ;) {
   331                 value[i] = (char) (hibyte | (ascii[i + offset] & 0xff));
   332             }
   333         }
   334         this.r = new String(value, 0, count);
   335     }
   336 
   337     /**
   338      * Allocates a new {@code String} containing characters constructed from
   339      * an array of 8-bit integer values. Each character <i>c</i>in the
   340      * resulting string is constructed from the corresponding component
   341      * <i>b</i> in the byte array such that:
   342      *
   343      * <blockquote><pre>
   344      *     <b><i>c</i></b> == (char)(((hibyte &amp; 0xff) &lt;&lt; 8)
   345      *                         | (<b><i>b</i></b> &amp; 0xff))
   346      * </pre></blockquote>
   347      *
   348      * @deprecated  This method does not properly convert bytes into
   349      * characters.  As of JDK&nbsp;1.1, the preferred way to do this is via the
   350      * {@code String} constructors that take a {@link
   351      * java.nio.charset.Charset}, charset name, or that use the platform's
   352      * default charset.
   353      *
   354      * @param  ascii
   355      *         The bytes to be converted to characters
   356      *
   357      * @param  hibyte
   358      *         The top 8 bits of each 16-bit Unicode code unit
   359      *
   360      * @see  #String(byte[], int, int, java.lang.String)
   361      * @see  #String(byte[], int, int, java.nio.charset.Charset)
   362      * @see  #String(byte[], int, int)
   363      * @see  #String(byte[], java.lang.String)
   364      * @see  #String(byte[], java.nio.charset.Charset)
   365      * @see  #String(byte[])
   366      */
   367     @Deprecated
   368     public String(byte ascii[], int hibyte) {
   369         this(ascii, hibyte, 0, ascii.length);
   370     }
   371 
   372     /* Common private utility method used to bounds check the byte array
   373      * and requested offset & length values used by the String(byte[],..)
   374      * constructors.
   375      */
   376     private static void checkBounds(byte[] bytes, int offset, int length) {
   377         if (length < 0)
   378             throw new StringIndexOutOfBoundsException(length);
   379         if (offset < 0)
   380             throw new StringIndexOutOfBoundsException(offset);
   381         if (offset > bytes.length - length)
   382             throw new StringIndexOutOfBoundsException(offset + length);
   383     }
   384 
   385     /**
   386      * Constructs a new {@code String} by decoding the specified subarray of
   387      * bytes using the specified charset.  The length of the new {@code String}
   388      * is a function of the charset, and hence may not be equal to the length
   389      * of the subarray.
   390      *
   391      * <p> The behavior of this constructor when the given bytes are not valid
   392      * in the given charset is unspecified.  The {@link
   393      * java.nio.charset.CharsetDecoder} class should be used when more control
   394      * over the decoding process is required.
   395      *
   396      * @param  bytes
   397      *         The bytes to be decoded into characters
   398      *
   399      * @param  offset
   400      *         The index of the first byte to decode
   401      *
   402      * @param  length
   403      *         The number of bytes to decode
   404 
   405      * @param  charsetName
   406      *         The name of a supported {@linkplain java.nio.charset.Charset
   407      *         charset}
   408      *
   409      * @throws  UnsupportedEncodingException
   410      *          If the named charset is not supported
   411      *
   412      * @throws  IndexOutOfBoundsException
   413      *          If the {@code offset} and {@code length} arguments index
   414      *          characters outside the bounds of the {@code bytes} array
   415      *
   416      * @since  JDK1.1
   417      */
   418 //    public String(byte bytes[], int offset, int length, String charsetName)
   419 //        throws UnsupportedEncodingException
   420 //    {
   421 //        if (charsetName == null)
   422 //            throw new NullPointerException("charsetName");
   423 //        checkBounds(bytes, offset, length);
   424 //        char[] v = StringCoding.decode(charsetName, bytes, offset, length);
   425 //        this.offset = 0;
   426 //        this.count = v.length;
   427 //        this.value = v;
   428 //    }
   429 
   430     /**
   431      * Constructs a new {@code String} by decoding the specified subarray of
   432      * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
   433      * The length of the new {@code String} is a function of the charset, and
   434      * hence may not be equal to the length of the subarray.
   435      *
   436      * <p> This method always replaces malformed-input and unmappable-character
   437      * sequences with this charset's default replacement string.  The {@link
   438      * java.nio.charset.CharsetDecoder} class should be used when more control
   439      * over the decoding process is required.
   440      *
   441      * @param  bytes
   442      *         The bytes to be decoded into characters
   443      *
   444      * @param  offset
   445      *         The index of the first byte to decode
   446      *
   447      * @param  length
   448      *         The number of bytes to decode
   449      *
   450      * @param  charset
   451      *         The {@linkplain java.nio.charset.Charset charset} to be used to
   452      *         decode the {@code bytes}
   453      *
   454      * @throws  IndexOutOfBoundsException
   455      *          If the {@code offset} and {@code length} arguments index
   456      *          characters outside the bounds of the {@code bytes} array
   457      *
   458      * @since  1.6
   459      */
   460     /* don't want dependnecy on Charset
   461     public String(byte bytes[], int offset, int length, Charset charset) {
   462         if (charset == null)
   463             throw new NullPointerException("charset");
   464         checkBounds(bytes, offset, length);
   465         char[] v = StringCoding.decode(charset, bytes, offset, length);
   466         this.offset = 0;
   467         this.count = v.length;
   468         this.value = v;
   469     }
   470     */
   471 
   472     /**
   473      * Constructs a new {@code String} by decoding the specified array of bytes
   474      * using the specified {@linkplain java.nio.charset.Charset charset}.  The
   475      * length of the new {@code String} is a function of the charset, and hence
   476      * may not be equal to the length of the byte array.
   477      *
   478      * <p> The behavior of this constructor when the given bytes are not valid
   479      * in the given charset is unspecified.  The {@link
   480      * java.nio.charset.CharsetDecoder} class should be used when more control
   481      * over the decoding process is required.
   482      *
   483      * @param  bytes
   484      *         The bytes to be decoded into characters
   485      *
   486      * @param  charsetName
   487      *         The name of a supported {@linkplain java.nio.charset.Charset
   488      *         charset}
   489      *
   490      * @throws  UnsupportedEncodingException
   491      *          If the named charset is not supported
   492      *
   493      * @since  JDK1.1
   494      */
   495 //    public String(byte bytes[], String charsetName)
   496 //        throws UnsupportedEncodingException
   497 //    {
   498 //        this(bytes, 0, bytes.length, charsetName);
   499 //    }
   500 
   501     /**
   502      * Constructs a new {@code String} by decoding the specified array of
   503      * bytes using the specified {@linkplain java.nio.charset.Charset charset}.
   504      * The length of the new {@code String} is a function of the charset, and
   505      * hence may not be equal to the length of the byte array.
   506      *
   507      * <p> This method always replaces malformed-input and unmappable-character
   508      * sequences with this charset's default replacement string.  The {@link
   509      * java.nio.charset.CharsetDecoder} class should be used when more control
   510      * over the decoding process is required.
   511      *
   512      * @param  bytes
   513      *         The bytes to be decoded into characters
   514      *
   515      * @param  charset
   516      *         The {@linkplain java.nio.charset.Charset charset} to be used to
   517      *         decode the {@code bytes}
   518      *
   519      * @since  1.6
   520      */
   521     /* don't want dep on Charset
   522     public String(byte bytes[], Charset charset) {
   523         this(bytes, 0, bytes.length, charset);
   524     }
   525     */
   526 
   527     /**
   528      * Constructs a new {@code String} by decoding the specified subarray of
   529      * bytes using the platform's default charset.  The length of the new
   530      * {@code String} is a function of the charset, and hence may not be equal
   531      * to the length of the subarray.
   532      *
   533      * <p> The behavior of this constructor when the given bytes are not valid
   534      * in the default charset is unspecified.  The {@link
   535      * java.nio.charset.CharsetDecoder} class should be used when more control
   536      * over the decoding process is required.
   537      *
   538      * @param  bytes
   539      *         The bytes to be decoded into characters
   540      *
   541      * @param  offset
   542      *         The index of the first byte to decode
   543      *
   544      * @param  length
   545      *         The number of bytes to decode
   546      *
   547      * @throws  IndexOutOfBoundsException
   548      *          If the {@code offset} and the {@code length} arguments index
   549      *          characters outside the bounds of the {@code bytes} array
   550      *
   551      * @since  JDK1.1
   552      */
   553     public String(byte bytes[], int offset, int length) {
   554         checkBounds(bytes, offset, length);
   555         char[] v  = new char[length];
   556         for (int i = 0; i < length; i++) {
   557             v[i] = (char)bytes[offset++];
   558         }
   559         this.r = new String(v, 0, v.length);
   560     }
   561 
   562     /**
   563      * Constructs a new {@code String} by decoding the specified array of bytes
   564      * using the platform's default charset.  The length of the new {@code
   565      * String} is a function of the charset, and hence may not be equal to the
   566      * length of the byte array.
   567      *
   568      * <p> The behavior of this constructor when the given bytes are not valid
   569      * in the default charset is unspecified.  The {@link
   570      * java.nio.charset.CharsetDecoder} class should be used when more control
   571      * over the decoding process is required.
   572      *
   573      * @param  bytes
   574      *         The bytes to be decoded into characters
   575      *
   576      * @since  JDK1.1
   577      */
   578     public String(byte bytes[]) {
   579         this(bytes, 0, bytes.length);
   580     }
   581 
   582     /**
   583      * Allocates a new string that contains the sequence of characters
   584      * currently contained in the string buffer argument. The contents of the
   585      * string buffer are copied; subsequent modification of the string buffer
   586      * does not affect the newly created string.
   587      *
   588      * @param  buffer
   589      *         A {@code StringBuffer}
   590      */
   591     public String(StringBuffer buffer) {
   592         this.r = buffer.toString();
   593     }
   594 
   595     /**
   596      * Allocates a new string that contains the sequence of characters
   597      * currently contained in the string builder argument. The contents of the
   598      * string builder are copied; subsequent modification of the string builder
   599      * does not affect the newly created string.
   600      *
   601      * <p> This constructor is provided to ease migration to {@code
   602      * StringBuilder}. Obtaining a string from a string builder via the {@code
   603      * toString} method is likely to run faster and is generally preferred.
   604      *
   605      * @param   builder
   606      *          A {@code StringBuilder}
   607      *
   608      * @since  1.5
   609      */
   610     public String(StringBuilder builder) {
   611         this.r = builder.toString();
   612     }
   613 
   614     /**
   615      * Returns the length of this string.
   616      * The length is equal to the number of <a href="Character.html#unicode">Unicode
   617      * code units</a> in the string.
   618      *
   619      * @return  the length of the sequence of characters represented by this
   620      *          object.
   621      */
   622     @JavaScriptBody(args = {}, body = "return this.toString().length;")
   623     public int length() {
   624         throw new UnsupportedOperationException();
   625     }
   626 
   627     /**
   628      * Returns <tt>true</tt> if, and only if, {@link #length()} is <tt>0</tt>.
   629      *
   630      * @return <tt>true</tt> if {@link #length()} is <tt>0</tt>, otherwise
   631      * <tt>false</tt>
   632      *
   633      * @since 1.6
   634      */
   635     @JavaScriptBody(args = {}, body="return this.toString().length === 0;")
   636     public boolean isEmpty() {
   637         return length() == 0;
   638     }
   639 
   640     /**
   641      * Returns the <code>char</code> value at the
   642      * specified index. An index ranges from <code>0</code> to
   643      * <code>length() - 1</code>. The first <code>char</code> value of the sequence
   644      * is at index <code>0</code>, the next at index <code>1</code>,
   645      * and so on, as for array indexing.
   646      *
   647      * <p>If the <code>char</code> value specified by the index is a
   648      * <a href="Character.html#unicode">surrogate</a>, the surrogate
   649      * value is returned.
   650      *
   651      * @param      index   the index of the <code>char</code> value.
   652      * @return     the <code>char</code> value at the specified index of this string.
   653      *             The first <code>char</code> value is at index <code>0</code>.
   654      * @exception  IndexOutOfBoundsException  if the <code>index</code>
   655      *             argument is negative or not less than the length of this
   656      *             string.
   657      */
   658     @JavaScriptBody(args = { "index" }, 
   659         body = "return this.toString().charCodeAt(index);"
   660     )
   661     public char charAt(int index) {
   662         throw new UnsupportedOperationException();
   663     }
   664 
   665     /**
   666      * Returns the character (Unicode code point) at the specified
   667      * index. The index refers to <code>char</code> values
   668      * (Unicode code units) and ranges from <code>0</code> to
   669      * {@link #length()}<code> - 1</code>.
   670      *
   671      * <p> If the <code>char</code> value specified at the given index
   672      * is in the high-surrogate range, the following index is less
   673      * than the length of this <code>String</code>, and the
   674      * <code>char</code> value at the following index is in the
   675      * low-surrogate range, then the supplementary code point
   676      * corresponding to this surrogate pair is returned. Otherwise,
   677      * the <code>char</code> value at the given index is returned.
   678      *
   679      * @param      index the index to the <code>char</code> values
   680      * @return     the code point value of the character at the
   681      *             <code>index</code>
   682      * @exception  IndexOutOfBoundsException  if the <code>index</code>
   683      *             argument is negative or not less than the length of this
   684      *             string.
   685      * @since      1.5
   686      */
   687     public int codePointAt(int index) {
   688         if ((index < 0) || (index >= length())) {
   689             throw new StringIndexOutOfBoundsException(index);
   690         }
   691         return Character.codePointAtImpl(toCharArray(), offset() + index, offset() + length());
   692     }
   693 
   694     /**
   695      * Returns the character (Unicode code point) before the specified
   696      * index. The index refers to <code>char</code> values
   697      * (Unicode code units) and ranges from <code>1</code> to {@link
   698      * CharSequence#length() length}.
   699      *
   700      * <p> If the <code>char</code> value at <code>(index - 1)</code>
   701      * is in the low-surrogate range, <code>(index - 2)</code> is not
   702      * negative, and the <code>char</code> value at <code>(index -
   703      * 2)</code> is in the high-surrogate range, then the
   704      * supplementary code point value of the surrogate pair is
   705      * returned. If the <code>char</code> value at <code>index -
   706      * 1</code> is an unpaired low-surrogate or a high-surrogate, the
   707      * surrogate value is returned.
   708      *
   709      * @param     index the index following the code point that should be returned
   710      * @return    the Unicode code point value before the given index.
   711      * @exception IndexOutOfBoundsException if the <code>index</code>
   712      *            argument is less than 1 or greater than the length
   713      *            of this string.
   714      * @since     1.5
   715      */
   716     public int codePointBefore(int index) {
   717         int i = index - 1;
   718         if ((i < 0) || (i >= length())) {
   719             throw new StringIndexOutOfBoundsException(index);
   720         }
   721         return Character.codePointBeforeImpl(toCharArray(), offset() + index, offset());
   722     }
   723 
   724     /**
   725      * Returns the number of Unicode code points in the specified text
   726      * range of this <code>String</code>. The text range begins at the
   727      * specified <code>beginIndex</code> and extends to the
   728      * <code>char</code> at index <code>endIndex - 1</code>. Thus the
   729      * length (in <code>char</code>s) of the text range is
   730      * <code>endIndex-beginIndex</code>. Unpaired surrogates within
   731      * the text range count as one code point each.
   732      *
   733      * @param beginIndex the index to the first <code>char</code> of
   734      * the text range.
   735      * @param endIndex the index after the last <code>char</code> of
   736      * the text range.
   737      * @return the number of Unicode code points in the specified text
   738      * range
   739      * @exception IndexOutOfBoundsException if the
   740      * <code>beginIndex</code> is negative, or <code>endIndex</code>
   741      * is larger than the length of this <code>String</code>, or
   742      * <code>beginIndex</code> is larger than <code>endIndex</code>.
   743      * @since  1.5
   744      */
   745     public int codePointCount(int beginIndex, int endIndex) {
   746         if (beginIndex < 0 || endIndex > length() || beginIndex > endIndex) {
   747             throw new IndexOutOfBoundsException();
   748         }
   749         return Character.codePointCountImpl(toCharArray(), offset()+beginIndex, endIndex-beginIndex);
   750     }
   751 
   752     /**
   753      * Returns the index within this <code>String</code> that is
   754      * offset from the given <code>index</code> by
   755      * <code>codePointOffset</code> code points. Unpaired surrogates
   756      * within the text range given by <code>index</code> and
   757      * <code>codePointOffset</code> count as one code point each.
   758      *
   759      * @param index the index to be offset
   760      * @param codePointOffset the offset in code points
   761      * @return the index within this <code>String</code>
   762      * @exception IndexOutOfBoundsException if <code>index</code>
   763      *   is negative or larger then the length of this
   764      *   <code>String</code>, or if <code>codePointOffset</code> is positive
   765      *   and the substring starting with <code>index</code> has fewer
   766      *   than <code>codePointOffset</code> code points,
   767      *   or if <code>codePointOffset</code> is negative and the substring
   768      *   before <code>index</code> has fewer than the absolute value
   769      *   of <code>codePointOffset</code> code points.
   770      * @since 1.5
   771      */
   772     public int offsetByCodePoints(int index, int codePointOffset) {
   773         if (index < 0 || index > length()) {
   774             throw new IndexOutOfBoundsException();
   775         }
   776         return Character.offsetByCodePointsImpl(toCharArray(), offset(), length(),
   777                                                 offset()+index, codePointOffset) - offset();
   778     }
   779 
   780     /**
   781      * Copy characters from this string into dst starting at dstBegin.
   782      * This method doesn't perform any range checking.
   783      */
   784     @JavaScriptBody(args = { "arr", "to" }, body = 
   785         "var s = this.toString();\n" +
   786         "for (var i = 0; i < s.length; i++) {\n" +
   787         "   arr[to++] = s[i];\n" +
   788         "}"
   789     )
   790     void getChars(char dst[], int dstBegin) {
   791         System.arraycopy(toCharArray(), offset(), dst, dstBegin, length());
   792     }
   793 
   794     /**
   795      * Copies characters from this string into the destination character
   796      * array.
   797      * <p>
   798      * The first character to be copied is at index <code>srcBegin</code>;
   799      * the last character to be copied is at index <code>srcEnd-1</code>
   800      * (thus the total number of characters to be copied is
   801      * <code>srcEnd-srcBegin</code>). The characters are copied into the
   802      * subarray of <code>dst</code> starting at index <code>dstBegin</code>
   803      * and ending at index:
   804      * <p><blockquote><pre>
   805      *     dstbegin + (srcEnd-srcBegin) - 1
   806      * </pre></blockquote>
   807      *
   808      * @param      srcBegin   index of the first character in the string
   809      *                        to copy.
   810      * @param      srcEnd     index after the last character in the string
   811      *                        to copy.
   812      * @param      dst        the destination array.
   813      * @param      dstBegin   the start offset in the destination array.
   814      * @exception IndexOutOfBoundsException If any of the following
   815      *            is true:
   816      *            <ul><li><code>srcBegin</code> is negative.
   817      *            <li><code>srcBegin</code> is greater than <code>srcEnd</code>
   818      *            <li><code>srcEnd</code> is greater than the length of this
   819      *                string
   820      *            <li><code>dstBegin</code> is negative
   821      *            <li><code>dstBegin+(srcEnd-srcBegin)</code> is larger than
   822      *                <code>dst.length</code></ul>
   823      */
   824     @JavaScriptBody(args = { "beg", "end", "arr", "dst" }, body=
   825         "var s = this.toString();\n" +
   826         "while (beg < end) {\n" +
   827         "  arr[dst++] = s.charCodeAt(beg++);\n" +
   828         "}\n"
   829     )
   830     public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin) {
   831         if (srcBegin < 0) {
   832             throw new StringIndexOutOfBoundsException(srcBegin);
   833         }
   834         if (srcEnd > length()) {
   835             throw new StringIndexOutOfBoundsException(srcEnd);
   836         }
   837         if (srcBegin > srcEnd) {
   838             throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
   839         }
   840         System.arraycopy(toCharArray(), offset() + srcBegin, dst, dstBegin,
   841              srcEnd - srcBegin);
   842     }
   843 
   844     /**
   845      * Copies characters from this string into the destination byte array. Each
   846      * byte receives the 8 low-order bits of the corresponding character. The
   847      * eight high-order bits of each character are not copied and do not
   848      * participate in the transfer in any way.
   849      *
   850      * <p> The first character to be copied is at index {@code srcBegin}; the
   851      * last character to be copied is at index {@code srcEnd-1}.  The total
   852      * number of characters to be copied is {@code srcEnd-srcBegin}. The
   853      * characters, converted to bytes, are copied into the subarray of {@code
   854      * dst} starting at index {@code dstBegin} and ending at index:
   855      *
   856      * <blockquote><pre>
   857      *     dstbegin + (srcEnd-srcBegin) - 1
   858      * </pre></blockquote>
   859      *
   860      * @deprecated  This method does not properly convert characters into
   861      * bytes.  As of JDK&nbsp;1.1, the preferred way to do this is via the
   862      * {@link #getBytes()} method, which uses the platform's default charset.
   863      *
   864      * @param  srcBegin
   865      *         Index of the first character in the string to copy
   866      *
   867      * @param  srcEnd
   868      *         Index after the last character in the string to copy
   869      *
   870      * @param  dst
   871      *         The destination array
   872      *
   873      * @param  dstBegin
   874      *         The start offset in the destination array
   875      *
   876      * @throws  IndexOutOfBoundsException
   877      *          If any of the following is true:
   878      *          <ul>
   879      *            <li> {@code srcBegin} is negative
   880      *            <li> {@code srcBegin} is greater than {@code srcEnd}
   881      *            <li> {@code srcEnd} is greater than the length of this String
   882      *            <li> {@code dstBegin} is negative
   883      *            <li> {@code dstBegin+(srcEnd-srcBegin)} is larger than {@code
   884      *                 dst.length}
   885      *          </ul>
   886      */
   887     @Deprecated
   888     public void getBytes(int srcBegin, int srcEnd, byte dst[], int dstBegin) {
   889         if (srcBegin < 0) {
   890             throw new StringIndexOutOfBoundsException(srcBegin);
   891         }
   892         if (srcEnd > length()) {
   893             throw new StringIndexOutOfBoundsException(srcEnd);
   894         }
   895         if (srcBegin > srcEnd) {
   896             throw new StringIndexOutOfBoundsException(srcEnd - srcBegin);
   897         }
   898         int j = dstBegin;
   899         int n = offset() + srcEnd;
   900         int i = offset() + srcBegin;
   901         char[] val = toCharArray();   /* avoid getfield opcode */
   902 
   903         while (i < n) {
   904             dst[j++] = (byte)val[i++];
   905         }
   906     }
   907 
   908     /**
   909      * Encodes this {@code String} into a sequence of bytes using the named
   910      * charset, storing the result into a new byte array.
   911      *
   912      * <p> The behavior of this method when this string cannot be encoded in
   913      * the given charset is unspecified.  The {@link
   914      * java.nio.charset.CharsetEncoder} class should be used when more control
   915      * over the encoding process is required.
   916      *
   917      * @param  charsetName
   918      *         The name of a supported {@linkplain java.nio.charset.Charset
   919      *         charset}
   920      *
   921      * @return  The resultant byte array
   922      *
   923      * @throws  UnsupportedEncodingException
   924      *          If the named charset is not supported
   925      *
   926      * @since  JDK1.1
   927      */
   928 //    public byte[] getBytes(String charsetName)
   929 //        throws UnsupportedEncodingException
   930 //    {
   931 //        if (charsetName == null) throw new NullPointerException();
   932 //        return StringCoding.encode(charsetName, value, offset, count);
   933 //    }
   934 
   935     /**
   936      * Encodes this {@code String} into a sequence of bytes using the given
   937      * {@linkplain java.nio.charset.Charset charset}, storing the result into a
   938      * new byte array.
   939      *
   940      * <p> This method always replaces malformed-input and unmappable-character
   941      * sequences with this charset's default replacement byte array.  The
   942      * {@link java.nio.charset.CharsetEncoder} class should be used when more
   943      * control over the encoding process is required.
   944      *
   945      * @param  charset
   946      *         The {@linkplain java.nio.charset.Charset} to be used to encode
   947      *         the {@code String}
   948      *
   949      * @return  The resultant byte array
   950      *
   951      * @since  1.6
   952      */
   953     /* don't want dep on Charset
   954     public byte[] getBytes(Charset charset) {
   955         if (charset == null) throw new NullPointerException();
   956         return StringCoding.encode(charset, value, offset, count);
   957     }
   958     */
   959 
   960     /**
   961      * Encodes this {@code String} into a sequence of bytes using the
   962      * platform's default charset, storing the result into a new byte array.
   963      *
   964      * <p> The behavior of this method when this string cannot be encoded in
   965      * the default charset is unspecified.  The {@link
   966      * java.nio.charset.CharsetEncoder} class should be used when more control
   967      * over the encoding process is required.
   968      *
   969      * @return  The resultant byte array
   970      *
   971      * @since      JDK1.1
   972      */
   973     public byte[] getBytes() {
   974         byte[] arr = new byte[length()];
   975         for (int i = 0; i < arr.length; i++) {
   976             final char v = charAt(i);
   977             arr[i] = (byte)v;
   978         }
   979         return arr;
   980     }
   981 
   982     /**
   983      * Compares this string to the specified object.  The result is {@code
   984      * true} if and only if the argument is not {@code null} and is a {@code
   985      * String} object that represents the same sequence of characters as this
   986      * object.
   987      *
   988      * @param  anObject
   989      *         The object to compare this {@code String} against
   990      *
   991      * @return  {@code true} if the given object represents a {@code String}
   992      *          equivalent to this string, {@code false} otherwise
   993      *
   994      * @see  #compareTo(String)
   995      * @see  #equalsIgnoreCase(String)
   996      */
   997     @JavaScriptBody(args = { "obj" }, body = 
   998         "return obj != null && obj.$instOf_java_lang_String && "
   999         + "this.toString() === obj.toString();"
  1000     )
  1001     public boolean equals(Object anObject) {
  1002         if (this == anObject) {
  1003             return true;
  1004         }
  1005         if (anObject instanceof String) {
  1006             String anotherString = (String)anObject;
  1007             int n = length();
  1008             if (n == anotherString.length()) {
  1009                 char v1[] = toCharArray();
  1010                 char v2[] = anotherString.toCharArray();
  1011                 int i = offset();
  1012                 int j = anotherString.offset();
  1013                 while (n-- != 0) {
  1014                     if (v1[i++] != v2[j++])
  1015                         return false;
  1016                 }
  1017                 return true;
  1018             }
  1019         }
  1020         return false;
  1021     }
  1022 
  1023     /**
  1024      * Compares this string to the specified {@code StringBuffer}.  The result
  1025      * is {@code true} if and only if this {@code String} represents the same
  1026      * sequence of characters as the specified {@code StringBuffer}.
  1027      *
  1028      * @param  sb
  1029      *         The {@code StringBuffer} to compare this {@code String} against
  1030      *
  1031      * @return  {@code true} if this {@code String} represents the same
  1032      *          sequence of characters as the specified {@code StringBuffer},
  1033      *          {@code false} otherwise
  1034      *
  1035      * @since  1.4
  1036      */
  1037     public boolean contentEquals(StringBuffer sb) {
  1038         synchronized(sb) {
  1039             return contentEquals((CharSequence)sb);
  1040         }
  1041     }
  1042 
  1043     /**
  1044      * Compares this string to the specified {@code CharSequence}.  The result
  1045      * is {@code true} if and only if this {@code String} represents the same
  1046      * sequence of char values as the specified sequence.
  1047      *
  1048      * @param  cs
  1049      *         The sequence to compare this {@code String} against
  1050      *
  1051      * @return  {@code true} if this {@code String} represents the same
  1052      *          sequence of char values as the specified sequence, {@code
  1053      *          false} otherwise
  1054      *
  1055      * @since  1.5
  1056      */
  1057     public boolean contentEquals(CharSequence cs) {
  1058         if (length() != cs.length())
  1059             return false;
  1060         // Argument is a StringBuffer, StringBuilder
  1061         if (cs instanceof AbstractStringBuilder) {
  1062             char v1[] = toCharArray();
  1063             char v2[] = ((AbstractStringBuilder)cs).getValue();
  1064             int i = offset();
  1065             int j = 0;
  1066             int n = length();
  1067             while (n-- != 0) {
  1068                 if (v1[i++] != v2[j++])
  1069                     return false;
  1070             }
  1071             return true;
  1072         }
  1073         // Argument is a String
  1074         if (cs.equals(this))
  1075             return true;
  1076         // Argument is a generic CharSequence
  1077         char v1[] = toCharArray();
  1078         int i = offset();
  1079         int j = 0;
  1080         int n = length();
  1081         while (n-- != 0) {
  1082             if (v1[i++] != cs.charAt(j++))
  1083                 return false;
  1084         }
  1085         return true;
  1086     }
  1087 
  1088     /**
  1089      * Compares this {@code String} to another {@code String}, ignoring case
  1090      * considerations.  Two strings are considered equal ignoring case if they
  1091      * are of the same length and corresponding characters in the two strings
  1092      * are equal ignoring case.
  1093      *
  1094      * <p> Two characters {@code c1} and {@code c2} are considered the same
  1095      * ignoring case if at least one of the following is true:
  1096      * <ul>
  1097      *   <li> The two characters are the same (as compared by the
  1098      *        {@code ==} operator)
  1099      *   <li> Applying the method {@link
  1100      *        java.lang.Character#toUpperCase(char)} to each character
  1101      *        produces the same result
  1102      *   <li> Applying the method {@link
  1103      *        java.lang.Character#toLowerCase(char)} to each character
  1104      *        produces the same result
  1105      * </ul>
  1106      *
  1107      * @param  anotherString
  1108      *         The {@code String} to compare this {@code String} against
  1109      *
  1110      * @return  {@code true} if the argument is not {@code null} and it
  1111      *          represents an equivalent {@code String} ignoring case; {@code
  1112      *          false} otherwise
  1113      *
  1114      * @see  #equals(Object)
  1115      */
  1116     public boolean equalsIgnoreCase(String anotherString) {
  1117         return (this == anotherString) ? true :
  1118                (anotherString != null) && (anotherString.length() == length()) &&
  1119                regionMatches(true, 0, anotherString, 0, length());
  1120     }
  1121 
  1122     /**
  1123      * Compares two strings lexicographically.
  1124      * The comparison is based on the Unicode value of each character in
  1125      * the strings. The character sequence represented by this
  1126      * <code>String</code> object is compared lexicographically to the
  1127      * character sequence represented by the argument string. The result is
  1128      * a negative integer if this <code>String</code> object
  1129      * lexicographically precedes the argument string. The result is a
  1130      * positive integer if this <code>String</code> object lexicographically
  1131      * follows the argument string. The result is zero if the strings
  1132      * are equal; <code>compareTo</code> returns <code>0</code> exactly when
  1133      * the {@link #equals(Object)} method would return <code>true</code>.
  1134      * <p>
  1135      * This is the definition of lexicographic ordering. If two strings are
  1136      * different, then either they have different characters at some index
  1137      * that is a valid index for both strings, or their lengths are different,
  1138      * or both. If they have different characters at one or more index
  1139      * positions, let <i>k</i> be the smallest such index; then the string
  1140      * whose character at position <i>k</i> has the smaller value, as
  1141      * determined by using the &lt; operator, lexicographically precedes the
  1142      * other string. In this case, <code>compareTo</code> returns the
  1143      * difference of the two character values at position <code>k</code> in
  1144      * the two string -- that is, the value:
  1145      * <blockquote><pre>
  1146      * this.charAt(k)-anotherString.charAt(k)
  1147      * </pre></blockquote>
  1148      * If there is no index position at which they differ, then the shorter
  1149      * string lexicographically precedes the longer string. In this case,
  1150      * <code>compareTo</code> returns the difference of the lengths of the
  1151      * strings -- that is, the value:
  1152      * <blockquote><pre>
  1153      * this.length()-anotherString.length()
  1154      * </pre></blockquote>
  1155      *
  1156      * @param   anotherString   the <code>String</code> to be compared.
  1157      * @return  the value <code>0</code> if the argument string is equal to
  1158      *          this string; a value less than <code>0</code> if this string
  1159      *          is lexicographically less than the string argument; and a
  1160      *          value greater than <code>0</code> if this string is
  1161      *          lexicographically greater than the string argument.
  1162      */
  1163     public int compareTo(String anotherString) {
  1164         int len1 = length();
  1165         int len2 = anotherString.length();
  1166         int n = Math.min(len1, len2);
  1167         char v1[] = toCharArray();
  1168         char v2[] = anotherString.toCharArray();
  1169         int i = offset();
  1170         int j = anotherString.offset();
  1171 
  1172         if (i == j) {
  1173             int k = i;
  1174             int lim = n + i;
  1175             while (k < lim) {
  1176                 char c1 = v1[k];
  1177                 char c2 = v2[k];
  1178                 if (c1 != c2) {
  1179                     return c1 - c2;
  1180                 }
  1181                 k++;
  1182             }
  1183         } else {
  1184             while (n-- != 0) {
  1185                 char c1 = v1[i++];
  1186                 char c2 = v2[j++];
  1187                 if (c1 != c2) {
  1188                     return c1 - c2;
  1189                 }
  1190             }
  1191         }
  1192         return len1 - len2;
  1193     }
  1194 
  1195     /**
  1196      * A Comparator that orders <code>String</code> objects as by
  1197      * <code>compareToIgnoreCase</code>. This comparator is serializable.
  1198      * <p>
  1199      * Note that this Comparator does <em>not</em> take locale into account,
  1200      * and will result in an unsatisfactory ordering for certain locales.
  1201      * The java.text package provides <em>Collators</em> to allow
  1202      * locale-sensitive ordering.
  1203      *
  1204      * @see     java.text.Collator#compare(String, String)
  1205      * @since   1.2
  1206      */
  1207     public static final Comparator<String> CASE_INSENSITIVE_ORDER
  1208                                          = new CaseInsensitiveComparator();
  1209 
  1210     private static int offset() {
  1211         return 0;
  1212     }
  1213     
  1214     private static class CaseInsensitiveComparator
  1215                          implements Comparator<String>, java.io.Serializable {
  1216         // use serialVersionUID from JDK 1.2.2 for interoperability
  1217         private static final long serialVersionUID = 8575799808933029326L;
  1218 
  1219         public int compare(String s1, String s2) {
  1220             int n1 = s1.length();
  1221             int n2 = s2.length();
  1222             int min = Math.min(n1, n2);
  1223             for (int i = 0; i < min; i++) {
  1224                 char c1 = s1.charAt(i);
  1225                 char c2 = s2.charAt(i);
  1226                 if (c1 != c2) {
  1227                     c1 = Character.toUpperCase(c1);
  1228                     c2 = Character.toUpperCase(c2);
  1229                     if (c1 != c2) {
  1230                         c1 = Character.toLowerCase(c1);
  1231                         c2 = Character.toLowerCase(c2);
  1232                         if (c1 != c2) {
  1233                             // No overflow because of numeric promotion
  1234                             return c1 - c2;
  1235                         }
  1236                     }
  1237                 }
  1238             }
  1239             return n1 - n2;
  1240         }
  1241     }
  1242 
  1243     /**
  1244      * Compares two strings lexicographically, ignoring case
  1245      * differences. This method returns an integer whose sign is that of
  1246      * calling <code>compareTo</code> with normalized versions of the strings
  1247      * where case differences have been eliminated by calling
  1248      * <code>Character.toLowerCase(Character.toUpperCase(character))</code> on
  1249      * each character.
  1250      * <p>
  1251      * Note that this method does <em>not</em> take locale into account,
  1252      * and will result in an unsatisfactory ordering for certain locales.
  1253      * The java.text package provides <em>collators</em> to allow
  1254      * locale-sensitive ordering.
  1255      *
  1256      * @param   str   the <code>String</code> to be compared.
  1257      * @return  a negative integer, zero, or a positive integer as the
  1258      *          specified String is greater than, equal to, or less
  1259      *          than this String, ignoring case considerations.
  1260      * @see     java.text.Collator#compare(String, String)
  1261      * @since   1.2
  1262      */
  1263     public int compareToIgnoreCase(String str) {
  1264         return CASE_INSENSITIVE_ORDER.compare(this, str);
  1265     }
  1266 
  1267     /**
  1268      * Tests if two string regions are equal.
  1269      * <p>
  1270      * A substring of this <tt>String</tt> object is compared to a substring
  1271      * of the argument other. The result is true if these substrings
  1272      * represent identical character sequences. The substring of this
  1273      * <tt>String</tt> object to be compared begins at index <tt>toffset</tt>
  1274      * and has length <tt>len</tt>. The substring of other to be compared
  1275      * begins at index <tt>ooffset</tt> and has length <tt>len</tt>. The
  1276      * result is <tt>false</tt> if and only if at least one of the following
  1277      * is true:
  1278      * <ul><li><tt>toffset</tt> is negative.
  1279      * <li><tt>ooffset</tt> is negative.
  1280      * <li><tt>toffset+len</tt> is greater than the length of this
  1281      * <tt>String</tt> object.
  1282      * <li><tt>ooffset+len</tt> is greater than the length of the other
  1283      * argument.
  1284      * <li>There is some nonnegative integer <i>k</i> less than <tt>len</tt>
  1285      * such that:
  1286      * <tt>this.charAt(toffset+<i>k</i>)&nbsp;!=&nbsp;other.charAt(ooffset+<i>k</i>)</tt>
  1287      * </ul>
  1288      *
  1289      * @param   toffset   the starting offset of the subregion in this string.
  1290      * @param   other     the string argument.
  1291      * @param   ooffset   the starting offset of the subregion in the string
  1292      *                    argument.
  1293      * @param   len       the number of characters to compare.
  1294      * @return  <code>true</code> if the specified subregion of this string
  1295      *          exactly matches the specified subregion of the string argument;
  1296      *          <code>false</code> otherwise.
  1297      */
  1298     public boolean regionMatches(int toffset, String other, int ooffset,
  1299                                  int len) {
  1300         char ta[] = toCharArray();
  1301         int to = offset() + toffset;
  1302         char pa[] = other.toCharArray();
  1303         int po = other.offset() + ooffset;
  1304         // Note: toffset, ooffset, or len might be near -1>>>1.
  1305         if ((ooffset < 0) || (toffset < 0) || (toffset > (long)length() - len)
  1306             || (ooffset > (long)other.length() - len)) {
  1307             return false;
  1308         }
  1309         while (len-- > 0) {
  1310             if (ta[to++] != pa[po++]) {
  1311                 return false;
  1312             }
  1313         }
  1314         return true;
  1315     }
  1316 
  1317     /**
  1318      * Tests if two string regions are equal.
  1319      * <p>
  1320      * A substring of this <tt>String</tt> object is compared to a substring
  1321      * of the argument <tt>other</tt>. The result is <tt>true</tt> if these
  1322      * substrings represent character sequences that are the same, ignoring
  1323      * case if and only if <tt>ignoreCase</tt> is true. The substring of
  1324      * this <tt>String</tt> object to be compared begins at index
  1325      * <tt>toffset</tt> and has length <tt>len</tt>. The substring of
  1326      * <tt>other</tt> to be compared begins at index <tt>ooffset</tt> and
  1327      * has length <tt>len</tt>. The result is <tt>false</tt> if and only if
  1328      * at least one of the following is true:
  1329      * <ul><li><tt>toffset</tt> is negative.
  1330      * <li><tt>ooffset</tt> is negative.
  1331      * <li><tt>toffset+len</tt> is greater than the length of this
  1332      * <tt>String</tt> object.
  1333      * <li><tt>ooffset+len</tt> is greater than the length of the other
  1334      * argument.
  1335      * <li><tt>ignoreCase</tt> is <tt>false</tt> and there is some nonnegative
  1336      * integer <i>k</i> less than <tt>len</tt> such that:
  1337      * <blockquote><pre>
  1338      * this.charAt(toffset+k) != other.charAt(ooffset+k)
  1339      * </pre></blockquote>
  1340      * <li><tt>ignoreCase</tt> is <tt>true</tt> and there is some nonnegative
  1341      * integer <i>k</i> less than <tt>len</tt> such that:
  1342      * <blockquote><pre>
  1343      * Character.toLowerCase(this.charAt(toffset+k)) !=
  1344                Character.toLowerCase(other.charAt(ooffset+k))
  1345      * </pre></blockquote>
  1346      * and:
  1347      * <blockquote><pre>
  1348      * Character.toUpperCase(this.charAt(toffset+k)) !=
  1349      *         Character.toUpperCase(other.charAt(ooffset+k))
  1350      * </pre></blockquote>
  1351      * </ul>
  1352      *
  1353      * @param   ignoreCase   if <code>true</code>, ignore case when comparing
  1354      *                       characters.
  1355      * @param   toffset      the starting offset of the subregion in this
  1356      *                       string.
  1357      * @param   other        the string argument.
  1358      * @param   ooffset      the starting offset of the subregion in the string
  1359      *                       argument.
  1360      * @param   len          the number of characters to compare.
  1361      * @return  <code>true</code> if the specified subregion of this string
  1362      *          matches the specified subregion of the string argument;
  1363      *          <code>false</code> otherwise. Whether the matching is exact
  1364      *          or case insensitive depends on the <code>ignoreCase</code>
  1365      *          argument.
  1366      */
  1367     public boolean regionMatches(boolean ignoreCase, int toffset,
  1368                            String other, int ooffset, int len) {
  1369         char ta[] = toCharArray();
  1370         int to = offset() + toffset;
  1371         char pa[] = other.toCharArray();
  1372         int po = other.offset() + ooffset;
  1373         // Note: toffset, ooffset, or len might be near -1>>>1.
  1374         if ((ooffset < 0) || (toffset < 0) || (toffset > (long)length() - len) ||
  1375                 (ooffset > (long)other.length() - len)) {
  1376             return false;
  1377         }
  1378         while (len-- > 0) {
  1379             char c1 = ta[to++];
  1380             char c2 = pa[po++];
  1381             if (c1 == c2) {
  1382                 continue;
  1383             }
  1384             if (ignoreCase) {
  1385                 // If characters don't match but case may be ignored,
  1386                 // try converting both characters to uppercase.
  1387                 // If the results match, then the comparison scan should
  1388                 // continue.
  1389                 char u1 = Character.toUpperCase(c1);
  1390                 char u2 = Character.toUpperCase(c2);
  1391                 if (u1 == u2) {
  1392                     continue;
  1393                 }
  1394                 // Unfortunately, conversion to uppercase does not work properly
  1395                 // for the Georgian alphabet, which has strange rules about case
  1396                 // conversion.  So we need to make one last check before
  1397                 // exiting.
  1398                 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {
  1399                     continue;
  1400                 }
  1401             }
  1402             return false;
  1403         }
  1404         return true;
  1405     }
  1406 
  1407     /**
  1408      * Tests if the substring of this string beginning at the
  1409      * specified index starts with the specified prefix.
  1410      *
  1411      * @param   prefix    the prefix.
  1412      * @param   toffset   where to begin looking in this string.
  1413      * @return  <code>true</code> if the character sequence represented by the
  1414      *          argument is a prefix of the substring of this object starting
  1415      *          at index <code>toffset</code>; <code>false</code> otherwise.
  1416      *          The result is <code>false</code> if <code>toffset</code> is
  1417      *          negative or greater than the length of this
  1418      *          <code>String</code> object; otherwise the result is the same
  1419      *          as the result of the expression
  1420      *          <pre>
  1421      *          this.substring(toffset).startsWith(prefix)
  1422      *          </pre>
  1423      */
  1424     @JavaScriptBody(args = { "find", "from" }, body=
  1425         "find = find.toString();\n" +
  1426         "return this.toString().substring(from, from + find.length) === find;\n"
  1427     )
  1428     public boolean startsWith(String prefix, int toffset) {
  1429         char ta[] = toCharArray();
  1430         int to = offset() + toffset;
  1431         char pa[] = prefix.toCharArray();
  1432         int po = prefix.offset();
  1433         int pc = prefix.length();
  1434         // Note: toffset might be near -1>>>1.
  1435         if ((toffset < 0) || (toffset > length() - pc)) {
  1436             return false;
  1437         }
  1438         while (--pc >= 0) {
  1439             if (ta[to++] != pa[po++]) {
  1440                 return false;
  1441             }
  1442         }
  1443         return true;
  1444     }
  1445 
  1446     /**
  1447      * Tests if this string starts with the specified prefix.
  1448      *
  1449      * @param   prefix   the prefix.
  1450      * @return  <code>true</code> if the character sequence represented by the
  1451      *          argument is a prefix of the character sequence represented by
  1452      *          this string; <code>false</code> otherwise.
  1453      *          Note also that <code>true</code> will be returned if the
  1454      *          argument is an empty string or is equal to this
  1455      *          <code>String</code> object as determined by the
  1456      *          {@link #equals(Object)} method.
  1457      * @since   1. 0
  1458      */
  1459     public boolean startsWith(String prefix) {
  1460         return startsWith(prefix, 0);
  1461     }
  1462 
  1463     /**
  1464      * Tests if this string ends with the specified suffix.
  1465      *
  1466      * @param   suffix   the suffix.
  1467      * @return  <code>true</code> if the character sequence represented by the
  1468      *          argument is a suffix of the character sequence represented by
  1469      *          this object; <code>false</code> otherwise. Note that the
  1470      *          result will be <code>true</code> if the argument is the
  1471      *          empty string or is equal to this <code>String</code> object
  1472      *          as determined by the {@link #equals(Object)} method.
  1473      */
  1474     public boolean endsWith(String suffix) {
  1475         return startsWith(suffix, length() - suffix.length());
  1476     }
  1477 
  1478     /**
  1479      * Returns a hash code for this string. The hash code for a
  1480      * <code>String</code> object is computed as
  1481      * <blockquote><pre>
  1482      * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
  1483      * </pre></blockquote>
  1484      * using <code>int</code> arithmetic, where <code>s[i]</code> is the
  1485      * <i>i</i>th character of the string, <code>n</code> is the length of
  1486      * the string, and <code>^</code> indicates exponentiation.
  1487      * (The hash value of the empty string is zero.)
  1488      *
  1489      * @return  a hash code value for this object.
  1490      */
  1491     public int hashCode() {
  1492         return super.hashCode();
  1493     }
  1494     int computeHashCode() {
  1495         int h = 0;
  1496         if (h == 0 && length() > 0) {
  1497             int off = offset();
  1498             int len = length();
  1499 
  1500             for (int i = 0; i < len; i++) {
  1501                 h = 31*h + charAt(off++);
  1502             }
  1503         }
  1504         return h;
  1505     }
  1506 
  1507     /**
  1508      * Returns the index within this string of the first occurrence of
  1509      * the specified character. If a character with value
  1510      * <code>ch</code> occurs in the character sequence represented by
  1511      * this <code>String</code> object, then the index (in Unicode
  1512      * code units) of the first such occurrence is returned. For
  1513      * values of <code>ch</code> in the range from 0 to 0xFFFF
  1514      * (inclusive), this is the smallest value <i>k</i> such that:
  1515      * <blockquote><pre>
  1516      * this.charAt(<i>k</i>) == ch
  1517      * </pre></blockquote>
  1518      * is true. For other values of <code>ch</code>, it is the
  1519      * smallest value <i>k</i> such that:
  1520      * <blockquote><pre>
  1521      * this.codePointAt(<i>k</i>) == ch
  1522      * </pre></blockquote>
  1523      * is true. In either case, if no such character occurs in this
  1524      * string, then <code>-1</code> is returned.
  1525      *
  1526      * @param   ch   a character (Unicode code point).
  1527      * @return  the index of the first occurrence of the character in the
  1528      *          character sequence represented by this object, or
  1529      *          <code>-1</code> if the character does not occur.
  1530      */
  1531     public int indexOf(int ch) {
  1532         return indexOf(ch, 0);
  1533     }
  1534 
  1535     /**
  1536      * Returns the index within this string of the first occurrence of the
  1537      * specified character, starting the search at the specified index.
  1538      * <p>
  1539      * If a character with value <code>ch</code> occurs in the
  1540      * character sequence represented by this <code>String</code>
  1541      * object at an index no smaller than <code>fromIndex</code>, then
  1542      * the index of the first such occurrence is returned. For values
  1543      * of <code>ch</code> in the range from 0 to 0xFFFF (inclusive),
  1544      * this is the smallest value <i>k</i> such that:
  1545      * <blockquote><pre>
  1546      * (this.charAt(<i>k</i>) == ch) && (<i>k</i> &gt;= fromIndex)
  1547      * </pre></blockquote>
  1548      * is true. For other values of <code>ch</code>, it is the
  1549      * smallest value <i>k</i> such that:
  1550      * <blockquote><pre>
  1551      * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> &gt;= fromIndex)
  1552      * </pre></blockquote>
  1553      * is true. In either case, if no such character occurs in this
  1554      * string at or after position <code>fromIndex</code>, then
  1555      * <code>-1</code> is returned.
  1556      *
  1557      * <p>
  1558      * There is no restriction on the value of <code>fromIndex</code>. If it
  1559      * is negative, it has the same effect as if it were zero: this entire
  1560      * string may be searched. If it is greater than the length of this
  1561      * string, it has the same effect as if it were equal to the length of
  1562      * this string: <code>-1</code> is returned.
  1563      *
  1564      * <p>All indices are specified in <code>char</code> values
  1565      * (Unicode code units).
  1566      *
  1567      * @param   ch          a character (Unicode code point).
  1568      * @param   fromIndex   the index to start the search from.
  1569      * @return  the index of the first occurrence of the character in the
  1570      *          character sequence represented by this object that is greater
  1571      *          than or equal to <code>fromIndex</code>, or <code>-1</code>
  1572      *          if the character does not occur.
  1573      */
  1574     @JavaScriptBody(args = { "ch", "from" }, body = 
  1575         "if (typeof ch === 'number') ch = String.fromCharCode(ch);\n" +
  1576         "return this.toString().indexOf(ch, from);\n"
  1577     )
  1578     public int indexOf(int ch, int fromIndex) {
  1579         if (fromIndex < 0) {
  1580             fromIndex = 0;
  1581         } else if (fromIndex >= length()) {
  1582             // Note: fromIndex might be near -1>>>1.
  1583             return -1;
  1584         }
  1585 
  1586         if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
  1587             // handle most cases here (ch is a BMP code point or a
  1588             // negative value (invalid code point))
  1589             final char[] value = this.toCharArray();
  1590             final int offset = this.offset();
  1591             final int max = offset + length();
  1592             for (int i = offset + fromIndex; i < max ; i++) {
  1593                 if (value[i] == ch) {
  1594                     return i - offset;
  1595                 }
  1596             }
  1597             return -1;
  1598         } else {
  1599             return indexOfSupplementary(ch, fromIndex);
  1600         }
  1601     }
  1602 
  1603     /**
  1604      * Handles (rare) calls of indexOf with a supplementary character.
  1605      */
  1606     private int indexOfSupplementary(int ch, int fromIndex) {
  1607         if (Character.isValidCodePoint(ch)) {
  1608             final char[] value = this.toCharArray();
  1609             final int offset = this.offset();
  1610             final char hi = Character.highSurrogate(ch);
  1611             final char lo = Character.lowSurrogate(ch);
  1612             final int max = offset + length() - 1;
  1613             for (int i = offset + fromIndex; i < max; i++) {
  1614                 if (value[i] == hi && value[i+1] == lo) {
  1615                     return i - offset;
  1616                 }
  1617             }
  1618         }
  1619         return -1;
  1620     }
  1621 
  1622     /**
  1623      * Returns the index within this string of the last occurrence of
  1624      * the specified character. For values of <code>ch</code> in the
  1625      * range from 0 to 0xFFFF (inclusive), the index (in Unicode code
  1626      * units) returned is the largest value <i>k</i> such that:
  1627      * <blockquote><pre>
  1628      * this.charAt(<i>k</i>) == ch
  1629      * </pre></blockquote>
  1630      * is true. For other values of <code>ch</code>, it is the
  1631      * largest value <i>k</i> such that:
  1632      * <blockquote><pre>
  1633      * this.codePointAt(<i>k</i>) == ch
  1634      * </pre></blockquote>
  1635      * is true.  In either case, if no such character occurs in this
  1636      * string, then <code>-1</code> is returned.  The
  1637      * <code>String</code> is searched backwards starting at the last
  1638      * character.
  1639      *
  1640      * @param   ch   a character (Unicode code point).
  1641      * @return  the index of the last occurrence of the character in the
  1642      *          character sequence represented by this object, or
  1643      *          <code>-1</code> if the character does not occur.
  1644      */
  1645     public int lastIndexOf(int ch) {
  1646         return lastIndexOf(ch, length() - 1);
  1647     }
  1648 
  1649     /**
  1650      * Returns the index within this string of the last occurrence of
  1651      * the specified character, searching backward starting at the
  1652      * specified index. For values of <code>ch</code> in the range
  1653      * from 0 to 0xFFFF (inclusive), the index returned is the largest
  1654      * value <i>k</i> such that:
  1655      * <blockquote><pre>
  1656      * (this.charAt(<i>k</i>) == ch) && (<i>k</i> &lt;= fromIndex)
  1657      * </pre></blockquote>
  1658      * is true. For other values of <code>ch</code>, it is the
  1659      * largest value <i>k</i> such that:
  1660      * <blockquote><pre>
  1661      * (this.codePointAt(<i>k</i>) == ch) && (<i>k</i> &lt;= fromIndex)
  1662      * </pre></blockquote>
  1663      * is true. In either case, if no such character occurs in this
  1664      * string at or before position <code>fromIndex</code>, then
  1665      * <code>-1</code> is returned.
  1666      *
  1667      * <p>All indices are specified in <code>char</code> values
  1668      * (Unicode code units).
  1669      *
  1670      * @param   ch          a character (Unicode code point).
  1671      * @param   fromIndex   the index to start the search from. There is no
  1672      *          restriction on the value of <code>fromIndex</code>. If it is
  1673      *          greater than or equal to the length of this string, it has
  1674      *          the same effect as if it were equal to one less than the
  1675      *          length of this string: this entire string may be searched.
  1676      *          If it is negative, it has the same effect as if it were -1:
  1677      *          -1 is returned.
  1678      * @return  the index of the last occurrence of the character in the
  1679      *          character sequence represented by this object that is less
  1680      *          than or equal to <code>fromIndex</code>, or <code>-1</code>
  1681      *          if the character does not occur before that point.
  1682      */
  1683     @JavaScriptBody(args = { "ch", "from" }, body = 
  1684         "if (typeof ch === 'number') ch = String.fromCharCode(ch);\n" +
  1685         "return this.toString().lastIndexOf(ch, from);"
  1686     )
  1687     public int lastIndexOf(int ch, int fromIndex) {
  1688         if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
  1689             // handle most cases here (ch is a BMP code point or a
  1690             // negative value (invalid code point))
  1691             final char[] value = this.toCharArray();
  1692             final int offset = this.offset();
  1693             int i = offset + Math.min(fromIndex, length() - 1);
  1694             for (; i >= offset ; i--) {
  1695                 if (value[i] == ch) {
  1696                     return i - offset;
  1697                 }
  1698             }
  1699             return -1;
  1700         } else {
  1701             return lastIndexOfSupplementary(ch, fromIndex);
  1702         }
  1703     }
  1704 
  1705     /**
  1706      * Handles (rare) calls of lastIndexOf with a supplementary character.
  1707      */
  1708     private int lastIndexOfSupplementary(int ch, int fromIndex) {
  1709         if (Character.isValidCodePoint(ch)) {
  1710             final char[] value = this.toCharArray();
  1711             final int offset = this.offset();
  1712             char hi = Character.highSurrogate(ch);
  1713             char lo = Character.lowSurrogate(ch);
  1714             int i = offset + Math.min(fromIndex, length() - 2);
  1715             for (; i >= offset; i--) {
  1716                 if (value[i] == hi && value[i+1] == lo) {
  1717                     return i - offset;
  1718                 }
  1719             }
  1720         }
  1721         return -1;
  1722     }
  1723 
  1724     /**
  1725      * Returns the index within this string of the first occurrence of the
  1726      * specified substring.
  1727      *
  1728      * <p>The returned index is the smallest value <i>k</i> for which:
  1729      * <blockquote><pre>
  1730      * this.startsWith(str, <i>k</i>)
  1731      * </pre></blockquote>
  1732      * If no such value of <i>k</i> exists, then {@code -1} is returned.
  1733      *
  1734      * @param   str   the substring to search for.
  1735      * @return  the index of the first occurrence of the specified substring,
  1736      *          or {@code -1} if there is no such occurrence.
  1737      */
  1738     public int indexOf(String str) {
  1739         return indexOf(str, 0);
  1740     }
  1741 
  1742     /**
  1743      * Returns the index within this string of the first occurrence of the
  1744      * specified substring, starting at the specified index.
  1745      *
  1746      * <p>The returned index is the smallest value <i>k</i> for which:
  1747      * <blockquote><pre>
  1748      * <i>k</i> &gt;= fromIndex && this.startsWith(str, <i>k</i>)
  1749      * </pre></blockquote>
  1750      * If no such value of <i>k</i> exists, then {@code -1} is returned.
  1751      *
  1752      * @param   str         the substring to search for.
  1753      * @param   fromIndex   the index from which to start the search.
  1754      * @return  the index of the first occurrence of the specified substring,
  1755      *          starting at the specified index,
  1756      *          or {@code -1} if there is no such occurrence.
  1757      */
  1758     @JavaScriptBody(args = { "str", "fromIndex" }, body =
  1759         "return this.toString().indexOf(str.toString(), fromIndex);"
  1760     )
  1761     public native int indexOf(String str, int fromIndex);
  1762 
  1763     /**
  1764      * Returns the index within this string of the last occurrence of the
  1765      * specified substring.  The last occurrence of the empty string ""
  1766      * is considered to occur at the index value {@code this.length()}.
  1767      *
  1768      * <p>The returned index is the largest value <i>k</i> for which:
  1769      * <blockquote><pre>
  1770      * this.startsWith(str, <i>k</i>)
  1771      * </pre></blockquote>
  1772      * If no such value of <i>k</i> exists, then {@code -1} is returned.
  1773      *
  1774      * @param   str   the substring to search for.
  1775      * @return  the index of the last occurrence of the specified substring,
  1776      *          or {@code -1} if there is no such occurrence.
  1777      */
  1778     public int lastIndexOf(String str) {
  1779         return lastIndexOf(str, length());
  1780     }
  1781 
  1782     /**
  1783      * Returns the index within this string of the last occurrence of the
  1784      * specified substring, searching backward starting at the specified index.
  1785      *
  1786      * <p>The returned index is the largest value <i>k</i> for which:
  1787      * <blockquote><pre>
  1788      * <i>k</i> &lt;= fromIndex && this.startsWith(str, <i>k</i>)
  1789      * </pre></blockquote>
  1790      * If no such value of <i>k</i> exists, then {@code -1} is returned.
  1791      *
  1792      * @param   str         the substring to search for.
  1793      * @param   fromIndex   the index to start the search from.
  1794      * @return  the index of the last occurrence of the specified substring,
  1795      *          searching backward from the specified index,
  1796      *          or {@code -1} if there is no such occurrence.
  1797      */
  1798     @JavaScriptBody(args = { "s", "from" }, body = 
  1799         "return this.toString().lastIndexOf(s.toString(), from);"
  1800     )
  1801     public int lastIndexOf(String str, int fromIndex) {
  1802         return lastIndexOf(toCharArray(), offset(), length(), str.toCharArray(), str.offset(), str.length(), fromIndex);
  1803     }
  1804 
  1805     /**
  1806      * Code shared by String and StringBuffer to do searches. The
  1807      * source is the character array being searched, and the target
  1808      * is the string being searched for.
  1809      *
  1810      * @param   source       the characters being searched.
  1811      * @param   sourceOffset offset of the source string.
  1812      * @param   sourceCount  count of the source string.
  1813      * @param   target       the characters being searched for.
  1814      * @param   targetOffset offset of the target string.
  1815      * @param   targetCount  count of the target string.
  1816      * @param   fromIndex    the index to begin searching from.
  1817      */
  1818     static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
  1819                            char[] target, int targetOffset, int targetCount,
  1820                            int fromIndex) {
  1821         /*
  1822          * Check arguments; return immediately where possible. For
  1823          * consistency, don't check for null str.
  1824          */
  1825         int rightIndex = sourceCount - targetCount;
  1826         if (fromIndex < 0) {
  1827             return -1;
  1828         }
  1829         if (fromIndex > rightIndex) {
  1830             fromIndex = rightIndex;
  1831         }
  1832         /* Empty string always matches. */
  1833         if (targetCount == 0) {
  1834             return fromIndex;
  1835         }
  1836 
  1837         int strLastIndex = targetOffset + targetCount - 1;
  1838         char strLastChar = target[strLastIndex];
  1839         int min = sourceOffset + targetCount - 1;
  1840         int i = min + fromIndex;
  1841 
  1842     startSearchForLastChar:
  1843         while (true) {
  1844             while (i >= min && source[i] != strLastChar) {
  1845                 i--;
  1846             }
  1847             if (i < min) {
  1848                 return -1;
  1849             }
  1850             int j = i - 1;
  1851             int start = j - (targetCount - 1);
  1852             int k = strLastIndex - 1;
  1853 
  1854             while (j > start) {
  1855                 if (source[j--] != target[k--]) {
  1856                     i--;
  1857                     continue startSearchForLastChar;
  1858                 }
  1859             }
  1860             return start - sourceOffset + 1;
  1861         }
  1862     }
  1863 
  1864     /**
  1865      * Returns a new string that is a substring of this string. The
  1866      * substring begins with the character at the specified index and
  1867      * extends to the end of this string. <p>
  1868      * Examples:
  1869      * <blockquote><pre>
  1870      * "unhappy".substring(2) returns "happy"
  1871      * "Harbison".substring(3) returns "bison"
  1872      * "emptiness".substring(9) returns "" (an empty string)
  1873      * </pre></blockquote>
  1874      *
  1875      * @param      beginIndex   the beginning index, inclusive.
  1876      * @return     the specified substring.
  1877      * @exception  IndexOutOfBoundsException  if
  1878      *             <code>beginIndex</code> is negative or larger than the
  1879      *             length of this <code>String</code> object.
  1880      */
  1881     public String substring(int beginIndex) {
  1882         return substring(beginIndex, length());
  1883     }
  1884 
  1885     /**
  1886      * Returns a new string that is a substring of this string. The
  1887      * substring begins at the specified <code>beginIndex</code> and
  1888      * extends to the character at index <code>endIndex - 1</code>.
  1889      * Thus the length of the substring is <code>endIndex-beginIndex</code>.
  1890      * <p>
  1891      * Examples:
  1892      * <blockquote><pre>
  1893      * "hamburger".substring(4, 8) returns "urge"
  1894      * "smiles".substring(1, 5) returns "mile"
  1895      * </pre></blockquote>
  1896      *
  1897      * @param      beginIndex   the beginning index, inclusive.
  1898      * @param      endIndex     the ending index, exclusive.
  1899      * @return     the specified substring.
  1900      * @exception  IndexOutOfBoundsException  if the
  1901      *             <code>beginIndex</code> is negative, or
  1902      *             <code>endIndex</code> is larger than the length of
  1903      *             this <code>String</code> object, or
  1904      *             <code>beginIndex</code> is larger than
  1905      *             <code>endIndex</code>.
  1906      */
  1907     @JavaScriptBody(args = { "beginIndex", "endIndex" }, body = 
  1908         "return this.toString().substring(beginIndex, endIndex);"
  1909     )
  1910     public String substring(int beginIndex, int endIndex) {
  1911         if (beginIndex < 0) {
  1912             throw new StringIndexOutOfBoundsException(beginIndex);
  1913         }
  1914         if (endIndex > length()) {
  1915             throw new StringIndexOutOfBoundsException(endIndex);
  1916         }
  1917         if (beginIndex > endIndex) {
  1918             throw new StringIndexOutOfBoundsException(endIndex - beginIndex);
  1919         }
  1920         return ((beginIndex == 0) && (endIndex == length())) ? this :
  1921             new String(toCharArray(), offset() + beginIndex, endIndex - beginIndex);
  1922     }
  1923 
  1924     /**
  1925      * Returns a new character sequence that is a subsequence of this sequence.
  1926      *
  1927      * <p> An invocation of this method of the form
  1928      *
  1929      * <blockquote><pre>
  1930      * str.subSequence(begin,&nbsp;end)</pre></blockquote>
  1931      *
  1932      * behaves in exactly the same way as the invocation
  1933      *
  1934      * <blockquote><pre>
  1935      * str.substring(begin,&nbsp;end)</pre></blockquote>
  1936      *
  1937      * This method is defined so that the <tt>String</tt> class can implement
  1938      * the {@link CharSequence} interface. </p>
  1939      *
  1940      * @param      beginIndex   the begin index, inclusive.
  1941      * @param      endIndex     the end index, exclusive.
  1942      * @return     the specified subsequence.
  1943      *
  1944      * @throws  IndexOutOfBoundsException
  1945      *          if <tt>beginIndex</tt> or <tt>endIndex</tt> are negative,
  1946      *          if <tt>endIndex</tt> is greater than <tt>length()</tt>,
  1947      *          or if <tt>beginIndex</tt> is greater than <tt>startIndex</tt>
  1948      *
  1949      * @since 1.4
  1950      * @spec JSR-51
  1951      */
  1952     public CharSequence subSequence(int beginIndex, int endIndex) {
  1953         return this.substring(beginIndex, endIndex);
  1954     }
  1955 
  1956     /**
  1957      * Concatenates the specified string to the end of this string.
  1958      * <p>
  1959      * If the length of the argument string is <code>0</code>, then this
  1960      * <code>String</code> object is returned. Otherwise, a new
  1961      * <code>String</code> object is created, representing a character
  1962      * sequence that is the concatenation of the character sequence
  1963      * represented by this <code>String</code> object and the character
  1964      * sequence represented by the argument string.<p>
  1965      * Examples:
  1966      * <blockquote><pre>
  1967      * "cares".concat("s") returns "caress"
  1968      * "to".concat("get").concat("her") returns "together"
  1969      * </pre></blockquote>
  1970      *
  1971      * @param   str   the <code>String</code> that is concatenated to the end
  1972      *                of this <code>String</code>.
  1973      * @return  a string that represents the concatenation of this object's
  1974      *          characters followed by the string argument's characters.
  1975      */
  1976     public String concat(String str) {
  1977         int otherLen = str.length();
  1978         if (otherLen == 0) {
  1979             return this;
  1980         }
  1981         char buf[] = new char[length() + otherLen];
  1982         getChars(0, length(), buf, 0);
  1983         str.getChars(0, otherLen, buf, length());
  1984         return new String(buf, 0, length() + otherLen);
  1985     }
  1986 
  1987     /**
  1988      * Returns a new string resulting from replacing all occurrences of
  1989      * <code>oldChar</code> in this string with <code>newChar</code>.
  1990      * <p>
  1991      * If the character <code>oldChar</code> does not occur in the
  1992      * character sequence represented by this <code>String</code> object,
  1993      * then a reference to this <code>String</code> object is returned.
  1994      * Otherwise, a new <code>String</code> object is created that
  1995      * represents a character sequence identical to the character sequence
  1996      * represented by this <code>String</code> object, except that every
  1997      * occurrence of <code>oldChar</code> is replaced by an occurrence
  1998      * of <code>newChar</code>.
  1999      * <p>
  2000      * Examples:
  2001      * <blockquote><pre>
  2002      * "mesquite in your cellar".replace('e', 'o')
  2003      *         returns "mosquito in your collar"
  2004      * "the war of baronets".replace('r', 'y')
  2005      *         returns "the way of bayonets"
  2006      * "sparring with a purple porpoise".replace('p', 't')
  2007      *         returns "starring with a turtle tortoise"
  2008      * "JonL".replace('q', 'x') returns "JonL" (no change)
  2009      * </pre></blockquote>
  2010      *
  2011      * @param   oldChar   the old character.
  2012      * @param   newChar   the new character.
  2013      * @return  a string derived from this string by replacing every
  2014      *          occurrence of <code>oldChar</code> with <code>newChar</code>.
  2015      */
  2016     @JavaScriptBody(args = { "arg1", "arg2" }, body =
  2017         "if (typeof arg1 === 'number') arg1 = String.fromCharCode(arg1);\n" +
  2018         "if (typeof arg2 === 'number') arg2 = String.fromCharCode(arg2);\n" +
  2019         "var s = this.toString();\n" +
  2020         "for (;;) {\n" +
  2021         "  var ret = s.replace(arg1, arg2);\n" +
  2022         "  if (ret === s) {\n" +
  2023         "    return ret;\n" +
  2024         "  }\n" +
  2025         "  s = ret;\n" +
  2026         "}"
  2027     )
  2028     public String replace(char oldChar, char newChar) {
  2029         if (oldChar != newChar) {
  2030             int len = length();
  2031             int i = -1;
  2032             char[] val = toCharArray(); /* avoid getfield opcode */
  2033             int off = offset();   /* avoid getfield opcode */
  2034 
  2035             while (++i < len) {
  2036                 if (val[off + i] == oldChar) {
  2037                     break;
  2038                 }
  2039             }
  2040             if (i < len) {
  2041                 char buf[] = new char[len];
  2042                 for (int j = 0 ; j < i ; j++) {
  2043                     buf[j] = val[off+j];
  2044                 }
  2045                 while (i < len) {
  2046                     char c = val[off + i];
  2047                     buf[i] = (c == oldChar) ? newChar : c;
  2048                     i++;
  2049                 }
  2050                 return new String(buf, 0, len);
  2051             }
  2052         }
  2053         return this;
  2054     }
  2055 
  2056     /**
  2057      * Tells whether or not this string matches the given <a
  2058      * href="../util/regex/Pattern.html#sum">regular expression</a>.
  2059      *
  2060      * <p> An invocation of this method of the form
  2061      * <i>str</i><tt>.matches(</tt><i>regex</i><tt>)</tt> yields exactly the
  2062      * same result as the expression
  2063      *
  2064      * <blockquote><tt> {@link java.util.regex.Pattern}.{@link
  2065      * java.util.regex.Pattern#matches(String,CharSequence)
  2066      * matches}(</tt><i>regex</i><tt>,</tt> <i>str</i><tt>)</tt></blockquote>
  2067      *
  2068      * @param   regex
  2069      *          the regular expression to which this string is to be matched
  2070      *
  2071      * @return  <tt>true</tt> if, and only if, this string matches the
  2072      *          given regular expression
  2073      *
  2074      * @throws  PatternSyntaxException
  2075      *          if the regular expression's syntax is invalid
  2076      *
  2077      * @see java.util.regex.Pattern
  2078      *
  2079      * @since 1.4
  2080      * @spec JSR-51
  2081      */
  2082     @JavaScriptBody(args = { "regex" }, body = 
  2083           "var self = this.toString();\n"
  2084         + "var re = new RegExp(regex.toString());\n"
  2085         + "var r = re.exec(self);\n"
  2086         + "return r != null && r.length > 0 && self.length == r[0].length;"
  2087     )
  2088     public boolean matches(String regex) {
  2089         throw new UnsupportedOperationException();
  2090     }
  2091 
  2092     /**
  2093      * Returns true if and only if this string contains the specified
  2094      * sequence of char values.
  2095      *
  2096      * @param s the sequence to search for
  2097      * @return true if this string contains <code>s</code>, false otherwise
  2098      * @throws NullPointerException if <code>s</code> is <code>null</code>
  2099      * @since 1.5
  2100      */
  2101     public boolean contains(CharSequence s) {
  2102         return indexOf(s.toString()) > -1;
  2103     }
  2104 
  2105     /**
  2106      * Replaces the first substring of this string that matches the given <a
  2107      * href="../util/regex/Pattern.html#sum">regular expression</a> with the
  2108      * given replacement.
  2109      *
  2110      * <p> An invocation of this method of the form
  2111      * <i>str</i><tt>.replaceFirst(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
  2112      * yields exactly the same result as the expression
  2113      *
  2114      * <blockquote><tt>
  2115      * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
  2116      * compile}(</tt><i>regex</i><tt>).{@link
  2117      * java.util.regex.Pattern#matcher(java.lang.CharSequence)
  2118      * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceFirst
  2119      * replaceFirst}(</tt><i>repl</i><tt>)</tt></blockquote>
  2120      *
  2121      *<p>
  2122      * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
  2123      * replacement string may cause the results to be different than if it were
  2124      * being treated as a literal replacement string; see
  2125      * {@link java.util.regex.Matcher#replaceFirst}.
  2126      * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
  2127      * meaning of these characters, if desired.
  2128      *
  2129      * @param   regex
  2130      *          the regular expression to which this string is to be matched
  2131      * @param   replacement
  2132      *          the string to be substituted for the first match
  2133      *
  2134      * @return  The resulting <tt>String</tt>
  2135      *
  2136      * @throws  PatternSyntaxException
  2137      *          if the regular expression's syntax is invalid
  2138      *
  2139      * @see java.util.regex.Pattern
  2140      *
  2141      * @since 1.4
  2142      * @spec JSR-51
  2143      */
  2144     public String replaceFirst(String regex, String replacement) {
  2145         throw new UnsupportedOperationException();
  2146     }
  2147 
  2148     /**
  2149      * Replaces each substring of this string that matches the given <a
  2150      * href="../util/regex/Pattern.html#sum">regular expression</a> with the
  2151      * given replacement.
  2152      *
  2153      * <p> An invocation of this method of the form
  2154      * <i>str</i><tt>.replaceAll(</tt><i>regex</i><tt>,</tt> <i>repl</i><tt>)</tt>
  2155      * yields exactly the same result as the expression
  2156      *
  2157      * <blockquote><tt>
  2158      * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
  2159      * compile}(</tt><i>regex</i><tt>).{@link
  2160      * java.util.regex.Pattern#matcher(java.lang.CharSequence)
  2161      * matcher}(</tt><i>str</i><tt>).{@link java.util.regex.Matcher#replaceAll
  2162      * replaceAll}(</tt><i>repl</i><tt>)</tt></blockquote>
  2163      *
  2164      *<p>
  2165      * Note that backslashes (<tt>\</tt>) and dollar signs (<tt>$</tt>) in the
  2166      * replacement string may cause the results to be different than if it were
  2167      * being treated as a literal replacement string; see
  2168      * {@link java.util.regex.Matcher#replaceAll Matcher.replaceAll}.
  2169      * Use {@link java.util.regex.Matcher#quoteReplacement} to suppress the special
  2170      * meaning of these characters, if desired.
  2171      *
  2172      * @param   regex
  2173      *          the regular expression to which this string is to be matched
  2174      * @param   replacement
  2175      *          the string to be substituted for each match
  2176      *
  2177      * @return  The resulting <tt>String</tt>
  2178      *
  2179      * @throws  PatternSyntaxException
  2180      *          if the regular expression's syntax is invalid
  2181      *
  2182      * @see java.util.regex.Pattern
  2183      *
  2184      * @since 1.4
  2185      * @spec JSR-51
  2186      */
  2187     public String replaceAll(String regex, String replacement) {
  2188         throw new UnsupportedOperationException();
  2189     }
  2190 
  2191     /**
  2192      * Replaces each substring of this string that matches the literal target
  2193      * sequence with the specified literal replacement sequence. The
  2194      * replacement proceeds from the beginning of the string to the end, for
  2195      * example, replacing "aa" with "b" in the string "aaa" will result in
  2196      * "ba" rather than "ab".
  2197      *
  2198      * @param  target The sequence of char values to be replaced
  2199      * @param  replacement The replacement sequence of char values
  2200      * @return  The resulting string
  2201      * @throws NullPointerException if <code>target</code> or
  2202      *         <code>replacement</code> is <code>null</code>.
  2203      * @since 1.5
  2204      */
  2205     public String replace(CharSequence target, CharSequence replacement) {
  2206         throw new UnsupportedOperationException("This one should be supported, but without dep on rest of regexp");
  2207     }
  2208 
  2209     /**
  2210      * Splits this string around matches of the given
  2211      * <a href="../util/regex/Pattern.html#sum">regular expression</a>.
  2212      *
  2213      * <p> The array returned by this method contains each substring of this
  2214      * string that is terminated by another substring that matches the given
  2215      * expression or is terminated by the end of the string.  The substrings in
  2216      * the array are in the order in which they occur in this string.  If the
  2217      * expression does not match any part of the input then the resulting array
  2218      * has just one element, namely this string.
  2219      *
  2220      * <p> The <tt>limit</tt> parameter controls the number of times the
  2221      * pattern is applied and therefore affects the length of the resulting
  2222      * array.  If the limit <i>n</i> is greater than zero then the pattern
  2223      * will be applied at most <i>n</i>&nbsp;-&nbsp;1 times, the array's
  2224      * length will be no greater than <i>n</i>, and the array's last entry
  2225      * will contain all input beyond the last matched delimiter.  If <i>n</i>
  2226      * is non-positive then the pattern will be applied as many times as
  2227      * possible and the array can have any length.  If <i>n</i> is zero then
  2228      * the pattern will be applied as many times as possible, the array can
  2229      * have any length, and trailing empty strings will be discarded.
  2230      *
  2231      * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the
  2232      * following results with these parameters:
  2233      *
  2234      * <blockquote><table cellpadding=1 cellspacing=0 summary="Split example showing regex, limit, and result">
  2235      * <tr>
  2236      *     <th>Regex</th>
  2237      *     <th>Limit</th>
  2238      *     <th>Result</th>
  2239      * </tr>
  2240      * <tr><td align=center>:</td>
  2241      *     <td align=center>2</td>
  2242      *     <td><tt>{ "boo", "and:foo" }</tt></td></tr>
  2243      * <tr><td align=center>:</td>
  2244      *     <td align=center>5</td>
  2245      *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
  2246      * <tr><td align=center>:</td>
  2247      *     <td align=center>-2</td>
  2248      *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
  2249      * <tr><td align=center>o</td>
  2250      *     <td align=center>5</td>
  2251      *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
  2252      * <tr><td align=center>o</td>
  2253      *     <td align=center>-2</td>
  2254      *     <td><tt>{ "b", "", ":and:f", "", "" }</tt></td></tr>
  2255      * <tr><td align=center>o</td>
  2256      *     <td align=center>0</td>
  2257      *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
  2258      * </table></blockquote>
  2259      *
  2260      * <p> An invocation of this method of the form
  2261      * <i>str.</i><tt>split(</tt><i>regex</i><tt>,</tt>&nbsp;<i>n</i><tt>)</tt>
  2262      * yields the same result as the expression
  2263      *
  2264      * <blockquote>
  2265      * {@link java.util.regex.Pattern}.{@link java.util.regex.Pattern#compile
  2266      * compile}<tt>(</tt><i>regex</i><tt>)</tt>.{@link
  2267      * java.util.regex.Pattern#split(java.lang.CharSequence,int)
  2268      * split}<tt>(</tt><i>str</i><tt>,</tt>&nbsp;<i>n</i><tt>)</tt>
  2269      * </blockquote>
  2270      *
  2271      *
  2272      * @param  regex
  2273      *         the delimiting regular expression
  2274      *
  2275      * @param  limit
  2276      *         the result threshold, as described above
  2277      *
  2278      * @return  the array of strings computed by splitting this string
  2279      *          around matches of the given regular expression
  2280      *
  2281      * @throws  PatternSyntaxException
  2282      *          if the regular expression's syntax is invalid
  2283      *
  2284      * @see java.util.regex.Pattern
  2285      *
  2286      * @since 1.4
  2287      * @spec JSR-51
  2288      */
  2289     public String[] split(String regex, int limit) {
  2290         throw new UnsupportedOperationException("Needs regexp");
  2291     }
  2292 
  2293     /**
  2294      * Splits this string around matches of the given <a
  2295      * href="../util/regex/Pattern.html#sum">regular expression</a>.
  2296      *
  2297      * <p> This method works as if by invoking the two-argument {@link
  2298      * #split(String, int) split} method with the given expression and a limit
  2299      * argument of zero.  Trailing empty strings are therefore not included in
  2300      * the resulting array.
  2301      *
  2302      * <p> The string <tt>"boo:and:foo"</tt>, for example, yields the following
  2303      * results with these expressions:
  2304      *
  2305      * <blockquote><table cellpadding=1 cellspacing=0 summary="Split examples showing regex and result">
  2306      * <tr>
  2307      *  <th>Regex</th>
  2308      *  <th>Result</th>
  2309      * </tr>
  2310      * <tr><td align=center>:</td>
  2311      *     <td><tt>{ "boo", "and", "foo" }</tt></td></tr>
  2312      * <tr><td align=center>o</td>
  2313      *     <td><tt>{ "b", "", ":and:f" }</tt></td></tr>
  2314      * </table></blockquote>
  2315      *
  2316      *
  2317      * @param  regex
  2318      *         the delimiting regular expression
  2319      *
  2320      * @return  the array of strings computed by splitting this string
  2321      *          around matches of the given regular expression
  2322      *
  2323      * @throws  PatternSyntaxException
  2324      *          if the regular expression's syntax is invalid
  2325      *
  2326      * @see java.util.regex.Pattern
  2327      *
  2328      * @since 1.4
  2329      * @spec JSR-51
  2330      */
  2331     public String[] split(String regex) {
  2332         return split(regex, 0);
  2333     }
  2334 
  2335     /**
  2336      * Converts all of the characters in this <code>String</code> to lower
  2337      * case using the rules of the given <code>Locale</code>.  Case mapping is based
  2338      * on the Unicode Standard version specified by the {@link java.lang.Character Character}
  2339      * class. Since case mappings are not always 1:1 char mappings, the resulting
  2340      * <code>String</code> may be a different length than the original <code>String</code>.
  2341      * <p>
  2342      * Examples of lowercase  mappings are in the following table:
  2343      * <table border="1" summary="Lowercase mapping examples showing language code of locale, upper case, lower case, and description">
  2344      * <tr>
  2345      *   <th>Language Code of Locale</th>
  2346      *   <th>Upper Case</th>
  2347      *   <th>Lower Case</th>
  2348      *   <th>Description</th>
  2349      * </tr>
  2350      * <tr>
  2351      *   <td>tr (Turkish)</td>
  2352      *   <td>&#92;u0130</td>
  2353      *   <td>&#92;u0069</td>
  2354      *   <td>capital letter I with dot above -&gt; small letter i</td>
  2355      * </tr>
  2356      * <tr>
  2357      *   <td>tr (Turkish)</td>
  2358      *   <td>&#92;u0049</td>
  2359      *   <td>&#92;u0131</td>
  2360      *   <td>capital letter I -&gt; small letter dotless i </td>
  2361      * </tr>
  2362      * <tr>
  2363      *   <td>(all)</td>
  2364      *   <td>French Fries</td>
  2365      *   <td>french fries</td>
  2366      *   <td>lowercased all chars in String</td>
  2367      * </tr>
  2368      * <tr>
  2369      *   <td>(all)</td>
  2370      *   <td><img src="doc-files/capiota.gif" alt="capiota"><img src="doc-files/capchi.gif" alt="capchi">
  2371      *       <img src="doc-files/captheta.gif" alt="captheta"><img src="doc-files/capupsil.gif" alt="capupsil">
  2372      *       <img src="doc-files/capsigma.gif" alt="capsigma"></td>
  2373      *   <td><img src="doc-files/iota.gif" alt="iota"><img src="doc-files/chi.gif" alt="chi">
  2374      *       <img src="doc-files/theta.gif" alt="theta"><img src="doc-files/upsilon.gif" alt="upsilon">
  2375      *       <img src="doc-files/sigma1.gif" alt="sigma"></td>
  2376      *   <td>lowercased all chars in String</td>
  2377      * </tr>
  2378      * </table>
  2379      *
  2380      * @param locale use the case transformation rules for this locale
  2381      * @return the <code>String</code>, converted to lowercase.
  2382      * @see     java.lang.String#toLowerCase()
  2383      * @see     java.lang.String#toUpperCase()
  2384      * @see     java.lang.String#toUpperCase(Locale)
  2385      * @since   1.1
  2386      */
  2387 //    public String toLowerCase(Locale locale) {
  2388 //        if (locale == null) {
  2389 //            throw new NullPointerException();
  2390 //        }
  2391 //
  2392 //        int     firstUpper;
  2393 //
  2394 //        /* Now check if there are any characters that need to be changed. */
  2395 //        scan: {
  2396 //            for (firstUpper = 0 ; firstUpper < count; ) {
  2397 //                char c = value[offset+firstUpper];
  2398 //                if ((c >= Character.MIN_HIGH_SURROGATE) &&
  2399 //                    (c <= Character.MAX_HIGH_SURROGATE)) {
  2400 //                    int supplChar = codePointAt(firstUpper);
  2401 //                    if (supplChar != Character.toLowerCase(supplChar)) {
  2402 //                        break scan;
  2403 //                    }
  2404 //                    firstUpper += Character.charCount(supplChar);
  2405 //                } else {
  2406 //                    if (c != Character.toLowerCase(c)) {
  2407 //                        break scan;
  2408 //                    }
  2409 //                    firstUpper++;
  2410 //                }
  2411 //            }
  2412 //            return this;
  2413 //        }
  2414 //
  2415 //        char[]  result = new char[count];
  2416 //        int     resultOffset = 0;  /* result may grow, so i+resultOffset
  2417 //                                    * is the write location in result */
  2418 //
  2419 //        /* Just copy the first few lowerCase characters. */
  2420 //        System.arraycopy(value, offset, result, 0, firstUpper);
  2421 //
  2422 //        String lang = locale.getLanguage();
  2423 //        boolean localeDependent =
  2424 //            (lang == "tr" || lang == "az" || lang == "lt");
  2425 //        char[] lowerCharArray;
  2426 //        int lowerChar;
  2427 //        int srcChar;
  2428 //        int srcCount;
  2429 //        for (int i = firstUpper; i < count; i += srcCount) {
  2430 //            srcChar = (int)value[offset+i];
  2431 //            if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
  2432 //                (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
  2433 //                srcChar = codePointAt(i);
  2434 //                srcCount = Character.charCount(srcChar);
  2435 //            } else {
  2436 //                srcCount = 1;
  2437 //            }
  2438 //            if (localeDependent || srcChar == '\u03A3') { // GREEK CAPITAL LETTER SIGMA
  2439 //                lowerChar = ConditionalSpecialCasing.toLowerCaseEx(this, i, locale);
  2440 //            } else if (srcChar == '\u0130') { // LATIN CAPITAL LETTER I DOT
  2441 //                lowerChar = Character.ERROR;
  2442 //            } else {
  2443 //                lowerChar = Character.toLowerCase(srcChar);
  2444 //            }
  2445 //            if ((lowerChar == Character.ERROR) ||
  2446 //                (lowerChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
  2447 //                if (lowerChar == Character.ERROR) {
  2448 //                     if (!localeDependent && srcChar == '\u0130') {
  2449 //                         lowerCharArray =
  2450 //                             ConditionalSpecialCasing.toLowerCaseCharArray(this, i, Locale.ENGLISH);
  2451 //                     } else {
  2452 //                        lowerCharArray =
  2453 //                            ConditionalSpecialCasing.toLowerCaseCharArray(this, i, locale);
  2454 //                     }
  2455 //                } else if (srcCount == 2) {
  2456 //                    resultOffset += Character.toChars(lowerChar, result, i + resultOffset) - srcCount;
  2457 //                    continue;
  2458 //                } else {
  2459 //                    lowerCharArray = Character.toChars(lowerChar);
  2460 //                }
  2461 //
  2462 //                /* Grow result if needed */
  2463 //                int mapLen = lowerCharArray.length;
  2464 //                if (mapLen > srcCount) {
  2465 //                    char[] result2 = new char[result.length + mapLen - srcCount];
  2466 //                    System.arraycopy(result, 0, result2, 0,
  2467 //                        i + resultOffset);
  2468 //                    result = result2;
  2469 //                }
  2470 //                for (int x=0; x<mapLen; ++x) {
  2471 //                    result[i+resultOffset+x] = lowerCharArray[x];
  2472 //                }
  2473 //                resultOffset += (mapLen - srcCount);
  2474 //            } else {
  2475 //                result[i+resultOffset] = (char)lowerChar;
  2476 //            }
  2477 //        }
  2478 //        return new String(0, count+resultOffset, result);
  2479 //    }
  2480 
  2481     /**
  2482      * Converts all of the characters in this <code>String</code> to lower
  2483      * case using the rules of the default locale. This is equivalent to calling
  2484      * <code>toLowerCase(Locale.getDefault())</code>.
  2485      * <p>
  2486      * <b>Note:</b> This method is locale sensitive, and may produce unexpected
  2487      * results if used for strings that are intended to be interpreted locale
  2488      * independently.
  2489      * Examples are programming language identifiers, protocol keys, and HTML
  2490      * tags.
  2491      * For instance, <code>"TITLE".toLowerCase()</code> in a Turkish locale
  2492      * returns <code>"t\u005Cu0131tle"</code>, where '\u005Cu0131' is the
  2493      * LATIN SMALL LETTER DOTLESS I character.
  2494      * To obtain correct results for locale insensitive strings, use
  2495      * <code>toLowerCase(Locale.ENGLISH)</code>.
  2496      * <p>
  2497      * @return  the <code>String</code>, converted to lowercase.
  2498      * @see     java.lang.String#toLowerCase(Locale)
  2499      */
  2500     @JavaScriptBody(args = {}, body = "return this.toLowerCase();")
  2501     public String toLowerCase() {
  2502         throw new UnsupportedOperationException("Should be supported but without connection to locale");
  2503     }
  2504 
  2505     /**
  2506      * Converts all of the characters in this <code>String</code> to upper
  2507      * case using the rules of the given <code>Locale</code>. Case mapping is based
  2508      * on the Unicode Standard version specified by the {@link java.lang.Character Character}
  2509      * class. Since case mappings are not always 1:1 char mappings, the resulting
  2510      * <code>String</code> may be a different length than the original <code>String</code>.
  2511      * <p>
  2512      * Examples of locale-sensitive and 1:M case mappings are in the following table.
  2513      * <p>
  2514      * <table border="1" summary="Examples of locale-sensitive and 1:M case mappings. Shows Language code of locale, lower case, upper case, and description.">
  2515      * <tr>
  2516      *   <th>Language Code of Locale</th>
  2517      *   <th>Lower Case</th>
  2518      *   <th>Upper Case</th>
  2519      *   <th>Description</th>
  2520      * </tr>
  2521      * <tr>
  2522      *   <td>tr (Turkish)</td>
  2523      *   <td>&#92;u0069</td>
  2524      *   <td>&#92;u0130</td>
  2525      *   <td>small letter i -&gt; capital letter I with dot above</td>
  2526      * </tr>
  2527      * <tr>
  2528      *   <td>tr (Turkish)</td>
  2529      *   <td>&#92;u0131</td>
  2530      *   <td>&#92;u0049</td>
  2531      *   <td>small letter dotless i -&gt; capital letter I</td>
  2532      * </tr>
  2533      * <tr>
  2534      *   <td>(all)</td>
  2535      *   <td>&#92;u00df</td>
  2536      *   <td>&#92;u0053 &#92;u0053</td>
  2537      *   <td>small letter sharp s -&gt; two letters: SS</td>
  2538      * </tr>
  2539      * <tr>
  2540      *   <td>(all)</td>
  2541      *   <td>Fahrvergn&uuml;gen</td>
  2542      *   <td>FAHRVERGN&Uuml;GEN</td>
  2543      *   <td></td>
  2544      * </tr>
  2545      * </table>
  2546      * @param locale use the case transformation rules for this locale
  2547      * @return the <code>String</code>, converted to uppercase.
  2548      * @see     java.lang.String#toUpperCase()
  2549      * @see     java.lang.String#toLowerCase()
  2550      * @see     java.lang.String#toLowerCase(Locale)
  2551      * @since   1.1
  2552      */
  2553     /* not for javascript 
  2554     public String toUpperCase(Locale locale) {
  2555         if (locale == null) {
  2556             throw new NullPointerException();
  2557         }
  2558 
  2559         int     firstLower;
  2560 
  2561         // Now check if there are any characters that need to be changed. 
  2562         scan: {
  2563             for (firstLower = 0 ; firstLower < count; ) {
  2564                 int c = (int)value[offset+firstLower];
  2565                 int srcCount;
  2566                 if ((c >= Character.MIN_HIGH_SURROGATE) &&
  2567                     (c <= Character.MAX_HIGH_SURROGATE)) {
  2568                     c = codePointAt(firstLower);
  2569                     srcCount = Character.charCount(c);
  2570                 } else {
  2571                     srcCount = 1;
  2572                 }
  2573                 int upperCaseChar = Character.toUpperCaseEx(c);
  2574                 if ((upperCaseChar == Character.ERROR) ||
  2575                     (c != upperCaseChar)) {
  2576                     break scan;
  2577                 }
  2578                 firstLower += srcCount;
  2579             }
  2580             return this;
  2581         }
  2582 
  2583         char[]  result       = new char[count]; /* may grow *
  2584         int     resultOffset = 0;  /* result may grow, so i+resultOffset
  2585                                     * is the write location in result *
  2586 
  2587         /* Just copy the first few upperCase characters. *
  2588         System.arraycopy(value, offset, result, 0, firstLower);
  2589 
  2590         String lang = locale.getLanguage();
  2591         boolean localeDependent =
  2592             (lang == "tr" || lang == "az" || lang == "lt");
  2593         char[] upperCharArray;
  2594         int upperChar;
  2595         int srcChar;
  2596         int srcCount;
  2597         for (int i = firstLower; i < count; i += srcCount) {
  2598             srcChar = (int)value[offset+i];
  2599             if ((char)srcChar >= Character.MIN_HIGH_SURROGATE &&
  2600                 (char)srcChar <= Character.MAX_HIGH_SURROGATE) {
  2601                 srcChar = codePointAt(i);
  2602                 srcCount = Character.charCount(srcChar);
  2603             } else {
  2604                 srcCount = 1;
  2605             }
  2606             if (localeDependent) {
  2607                 upperChar = ConditionalSpecialCasing.toUpperCaseEx(this, i, locale);
  2608             } else {
  2609                 upperChar = Character.toUpperCaseEx(srcChar);
  2610             }
  2611             if ((upperChar == Character.ERROR) ||
  2612                 (upperChar >= Character.MIN_SUPPLEMENTARY_CODE_POINT)) {
  2613                 if (upperChar == Character.ERROR) {
  2614                     if (localeDependent) {
  2615                         upperCharArray =
  2616                             ConditionalSpecialCasing.toUpperCaseCharArray(this, i, locale);
  2617                     } else {
  2618                         upperCharArray = Character.toUpperCaseCharArray(srcChar);
  2619                     }
  2620                 } else if (srcCount == 2) {
  2621                     resultOffset += Character.toChars(upperChar, result, i + resultOffset) - srcCount;
  2622                     continue;
  2623                 } else {
  2624                     upperCharArray = Character.toChars(upperChar);
  2625                 }
  2626 
  2627                 /* Grow result if needed *
  2628                 int mapLen = upperCharArray.length;
  2629                 if (mapLen > srcCount) {
  2630                     char[] result2 = new char[result.length + mapLen - srcCount];
  2631                     System.arraycopy(result, 0, result2, 0,
  2632                         i + resultOffset);
  2633                     result = result2;
  2634                 }
  2635                 for (int x=0; x<mapLen; ++x) {
  2636                     result[i+resultOffset+x] = upperCharArray[x];
  2637                 }
  2638                 resultOffset += (mapLen - srcCount);
  2639             } else {
  2640                 result[i+resultOffset] = (char)upperChar;
  2641             }
  2642         }
  2643         return new String(0, count+resultOffset, result);
  2644     }
  2645     */
  2646 
  2647     /**
  2648      * Converts all of the characters in this <code>String</code> to upper
  2649      * case using the rules of the default locale. This method is equivalent to
  2650      * <code>toUpperCase(Locale.getDefault())</code>.
  2651      * <p>
  2652      * <b>Note:</b> This method is locale sensitive, and may produce unexpected
  2653      * results if used for strings that are intended to be interpreted locale
  2654      * independently.
  2655      * Examples are programming language identifiers, protocol keys, and HTML
  2656      * tags.
  2657      * For instance, <code>"title".toUpperCase()</code> in a Turkish locale
  2658      * returns <code>"T\u005Cu0130TLE"</code>, where '\u005Cu0130' is the
  2659      * LATIN CAPITAL LETTER I WITH DOT ABOVE character.
  2660      * To obtain correct results for locale insensitive strings, use
  2661      * <code>toUpperCase(Locale.ENGLISH)</code>.
  2662      * <p>
  2663      * @return  the <code>String</code>, converted to uppercase.
  2664      * @see     java.lang.String#toUpperCase(Locale)
  2665      */
  2666     @JavaScriptBody(args = {}, body = "return this.toUpperCase();")
  2667     public String toUpperCase() {
  2668         throw new UnsupportedOperationException();
  2669     }
  2670 
  2671     /**
  2672      * Returns a copy of the string, with leading and trailing whitespace
  2673      * omitted.
  2674      * <p>
  2675      * If this <code>String</code> object represents an empty character
  2676      * sequence, or the first and last characters of character sequence
  2677      * represented by this <code>String</code> object both have codes
  2678      * greater than <code>'&#92;u0020'</code> (the space character), then a
  2679      * reference to this <code>String</code> object is returned.
  2680      * <p>
  2681      * Otherwise, if there is no character with a code greater than
  2682      * <code>'&#92;u0020'</code> in the string, then a new
  2683      * <code>String</code> object representing an empty string is created
  2684      * and returned.
  2685      * <p>
  2686      * Otherwise, let <i>k</i> be the index of the first character in the
  2687      * string whose code is greater than <code>'&#92;u0020'</code>, and let
  2688      * <i>m</i> be the index of the last character in the string whose code
  2689      * is greater than <code>'&#92;u0020'</code>. A new <code>String</code>
  2690      * object is created, representing the substring of this string that
  2691      * begins with the character at index <i>k</i> and ends with the
  2692      * character at index <i>m</i>-that is, the result of
  2693      * <code>this.substring(<i>k</i>,&nbsp;<i>m</i>+1)</code>.
  2694      * <p>
  2695      * This method may be used to trim whitespace (as defined above) from
  2696      * the beginning and end of a string.
  2697      *
  2698      * @return  A copy of this string with leading and trailing white
  2699      *          space removed, or this string if it has no leading or
  2700      *          trailing white space.
  2701      */
  2702     public String trim() {
  2703         int len = length();
  2704         int st = 0;
  2705         int off = offset();      /* avoid getfield opcode */
  2706         char[] val = toCharArray();    /* avoid getfield opcode */
  2707 
  2708         while ((st < len) && (val[off + st] <= ' ')) {
  2709             st++;
  2710         }
  2711         while ((st < len) && (val[off + len - 1] <= ' ')) {
  2712             len--;
  2713         }
  2714         return ((st > 0) || (len < length())) ? substring(st, len) : this;
  2715     }
  2716 
  2717     /**
  2718      * This object (which is already a string!) is itself returned.
  2719      *
  2720      * @return  the string itself.
  2721      */
  2722     @JavaScriptBody(args = {}, body = "return this.toString();")
  2723     public String toString() {
  2724         return this;
  2725     }
  2726 
  2727     /**
  2728      * Converts this string to a new character array.
  2729      *
  2730      * @return  a newly allocated character array whose length is the length
  2731      *          of this string and whose contents are initialized to contain
  2732      *          the character sequence represented by this string.
  2733      */
  2734     public char[] toCharArray() {
  2735         char result[] = new char[length()];
  2736         getChars(0, length(), result, 0);
  2737         return result;
  2738     }
  2739 
  2740     /**
  2741      * Returns a formatted string using the specified format string and
  2742      * arguments.
  2743      *
  2744      * <p> The locale always used is the one returned by {@link
  2745      * java.util.Locale#getDefault() Locale.getDefault()}.
  2746      *
  2747      * @param  format
  2748      *         A <a href="../util/Formatter.html#syntax">format string</a>
  2749      *
  2750      * @param  args
  2751      *         Arguments referenced by the format specifiers in the format
  2752      *         string.  If there are more arguments than format specifiers, the
  2753      *         extra arguments are ignored.  The number of arguments is
  2754      *         variable and may be zero.  The maximum number of arguments is
  2755      *         limited by the maximum dimension of a Java array as defined by
  2756      *         <cite>The Java&trade; Virtual Machine Specification</cite>.
  2757      *         The behaviour on a
  2758      *         <tt>null</tt> argument depends on the <a
  2759      *         href="../util/Formatter.html#syntax">conversion</a>.
  2760      *
  2761      * @throws  IllegalFormatException
  2762      *          If a format string contains an illegal syntax, a format
  2763      *          specifier that is incompatible with the given arguments,
  2764      *          insufficient arguments given the format string, or other
  2765      *          illegal conditions.  For specification of all possible
  2766      *          formatting errors, see the <a
  2767      *          href="../util/Formatter.html#detail">Details</a> section of the
  2768      *          formatter class specification.
  2769      *
  2770      * @throws  NullPointerException
  2771      *          If the <tt>format</tt> is <tt>null</tt>
  2772      *
  2773      * @return  A formatted string
  2774      *
  2775      * @see  java.util.Formatter
  2776      * @since  1.5
  2777      */
  2778     public static String format(String format, Object ... args) {
  2779         throw new UnsupportedOperationException();
  2780     }
  2781 
  2782     /**
  2783      * Returns a formatted string using the specified locale, format string,
  2784      * and arguments.
  2785      *
  2786      * @param  l
  2787      *         The {@linkplain java.util.Locale locale} to apply during
  2788      *         formatting.  If <tt>l</tt> is <tt>null</tt> then no localization
  2789      *         is applied.
  2790      *
  2791      * @param  format
  2792      *         A <a href="../util/Formatter.html#syntax">format string</a>
  2793      *
  2794      * @param  args
  2795      *         Arguments referenced by the format specifiers in the format
  2796      *         string.  If there are more arguments than format specifiers, the
  2797      *         extra arguments are ignored.  The number of arguments is
  2798      *         variable and may be zero.  The maximum number of arguments is
  2799      *         limited by the maximum dimension of a Java array as defined by
  2800      *         <cite>The Java&trade; Virtual Machine Specification</cite>.
  2801      *         The behaviour on a
  2802      *         <tt>null</tt> argument depends on the <a
  2803      *         href="../util/Formatter.html#syntax">conversion</a>.
  2804      *
  2805      * @throws  IllegalFormatException
  2806      *          If a format string contains an illegal syntax, a format
  2807      *          specifier that is incompatible with the given arguments,
  2808      *          insufficient arguments given the format string, or other
  2809      *          illegal conditions.  For specification of all possible
  2810      *          formatting errors, see the <a
  2811      *          href="../util/Formatter.html#detail">Details</a> section of the
  2812      *          formatter class specification
  2813      *
  2814      * @throws  NullPointerException
  2815      *          If the <tt>format</tt> is <tt>null</tt>
  2816      *
  2817      * @return  A formatted string
  2818      *
  2819      * @see  java.util.Formatter
  2820      * @since  1.5
  2821      */
  2822 //    public static String format(Locale l, String format, Object ... args) {
  2823 //        return new Formatter(l).format(format, args).toString();
  2824 //    }
  2825 
  2826     /**
  2827      * Returns the string representation of the <code>Object</code> argument.
  2828      *
  2829      * @param   obj   an <code>Object</code>.
  2830      * @return  if the argument is <code>null</code>, then a string equal to
  2831      *          <code>"null"</code>; otherwise, the value of
  2832      *          <code>obj.toString()</code> is returned.
  2833      * @see     java.lang.Object#toString()
  2834      */
  2835     public static String valueOf(Object obj) {
  2836         return (obj == null) ? "null" : obj.toString();
  2837     }
  2838 
  2839     /**
  2840      * Returns the string representation of the <code>char</code> array
  2841      * argument. The contents of the character array are copied; subsequent
  2842      * modification of the character array does not affect the newly
  2843      * created string.
  2844      *
  2845      * @param   data   a <code>char</code> array.
  2846      * @return  a newly allocated string representing the same sequence of
  2847      *          characters contained in the character array argument.
  2848      */
  2849     public static String valueOf(char data[]) {
  2850         return new String(data);
  2851     }
  2852 
  2853     /**
  2854      * Returns the string representation of a specific subarray of the
  2855      * <code>char</code> array argument.
  2856      * <p>
  2857      * The <code>offset</code> argument is the index of the first
  2858      * character of the subarray. The <code>count</code> argument
  2859      * specifies the length of the subarray. The contents of the subarray
  2860      * are copied; subsequent modification of the character array does not
  2861      * affect the newly created string.
  2862      *
  2863      * @param   data     the character array.
  2864      * @param   offset   the initial offset into the value of the
  2865      *                  <code>String</code>.
  2866      * @param   count    the length of the value of the <code>String</code>.
  2867      * @return  a string representing the sequence of characters contained
  2868      *          in the subarray of the character array argument.
  2869      * @exception IndexOutOfBoundsException if <code>offset</code> is
  2870      *          negative, or <code>count</code> is negative, or
  2871      *          <code>offset+count</code> is larger than
  2872      *          <code>data.length</code>.
  2873      */
  2874     public static String valueOf(char data[], int offset, int count) {
  2875         return new String(data, offset, count);
  2876     }
  2877 
  2878     /**
  2879      * Returns a String that represents the character sequence in the
  2880      * array specified.
  2881      *
  2882      * @param   data     the character array.
  2883      * @param   offset   initial offset of the subarray.
  2884      * @param   count    length of the subarray.
  2885      * @return  a <code>String</code> that contains the characters of the
  2886      *          specified subarray of the character array.
  2887      */
  2888     public static String copyValueOf(char data[], int offset, int count) {
  2889         // All public String constructors now copy the data.
  2890         return new String(data, offset, count);
  2891     }
  2892 
  2893     /**
  2894      * Returns a String that represents the character sequence in the
  2895      * array specified.
  2896      *
  2897      * @param   data   the character array.
  2898      * @return  a <code>String</code> that contains the characters of the
  2899      *          character array.
  2900      */
  2901     public static String copyValueOf(char data[]) {
  2902         return copyValueOf(data, 0, data.length);
  2903     }
  2904 
  2905     /**
  2906      * Returns the string representation of the <code>boolean</code> argument.
  2907      *
  2908      * @param   b   a <code>boolean</code>.
  2909      * @return  if the argument is <code>true</code>, a string equal to
  2910      *          <code>"true"</code> is returned; otherwise, a string equal to
  2911      *          <code>"false"</code> is returned.
  2912      */
  2913     public static String valueOf(boolean b) {
  2914         return b ? "true" : "false";
  2915     }
  2916 
  2917     /**
  2918      * Returns the string representation of the <code>char</code>
  2919      * argument.
  2920      *
  2921      * @param   c   a <code>char</code>.
  2922      * @return  a string of length <code>1</code> containing
  2923      *          as its single character the argument <code>c</code>.
  2924      */
  2925     public static String valueOf(char c) {
  2926         char data[] = {c};
  2927         return new String(data, 0, 1);
  2928     }
  2929 
  2930     /**
  2931      * Returns the string representation of the <code>int</code> argument.
  2932      * <p>
  2933      * The representation is exactly the one returned by the
  2934      * <code>Integer.toString</code> method of one argument.
  2935      *
  2936      * @param   i   an <code>int</code>.
  2937      * @return  a string representation of the <code>int</code> argument.
  2938      * @see     java.lang.Integer#toString(int, int)
  2939      */
  2940     public static String valueOf(int i) {
  2941         return Integer.toString(i);
  2942     }
  2943 
  2944     /**
  2945      * Returns the string representation of the <code>long</code> argument.
  2946      * <p>
  2947      * The representation is exactly the one returned by the
  2948      * <code>Long.toString</code> method of one argument.
  2949      *
  2950      * @param   l   a <code>long</code>.
  2951      * @return  a string representation of the <code>long</code> argument.
  2952      * @see     java.lang.Long#toString(long)
  2953      */
  2954     public static String valueOf(long l) {
  2955         return Long.toString(l);
  2956     }
  2957 
  2958     /**
  2959      * Returns the string representation of the <code>float</code> argument.
  2960      * <p>
  2961      * The representation is exactly the one returned by the
  2962      * <code>Float.toString</code> method of one argument.
  2963      *
  2964      * @param   f   a <code>float</code>.
  2965      * @return  a string representation of the <code>float</code> argument.
  2966      * @see     java.lang.Float#toString(float)
  2967      */
  2968     public static String valueOf(float f) {
  2969         return Float.toString(f);
  2970     }
  2971 
  2972     /**
  2973      * Returns the string representation of the <code>double</code> argument.
  2974      * <p>
  2975      * The representation is exactly the one returned by the
  2976      * <code>Double.toString</code> method of one argument.
  2977      *
  2978      * @param   d   a <code>double</code>.
  2979      * @return  a  string representation of the <code>double</code> argument.
  2980      * @see     java.lang.Double#toString(double)
  2981      */
  2982     public static String valueOf(double d) {
  2983         return Double.toString(d);
  2984     }
  2985 
  2986     /**
  2987      * Returns a canonical representation for the string object.
  2988      * <p>
  2989      * A pool of strings, initially empty, is maintained privately by the
  2990      * class <code>String</code>.
  2991      * <p>
  2992      * When the intern method is invoked, if the pool already contains a
  2993      * string equal to this <code>String</code> object as determined by
  2994      * the {@link #equals(Object)} method, then the string from the pool is
  2995      * returned. Otherwise, this <code>String</code> object is added to the
  2996      * pool and a reference to this <code>String</code> object is returned.
  2997      * <p>
  2998      * It follows that for any two strings <code>s</code> and <code>t</code>,
  2999      * <code>s.intern()&nbsp;==&nbsp;t.intern()</code> is <code>true</code>
  3000      * if and only if <code>s.equals(t)</code> is <code>true</code>.
  3001      * <p>
  3002      * All literal strings and string-valued constant expressions are
  3003      * interned. String literals are defined in section 3.10.5 of the
  3004      * <cite>The Java&trade; Language Specification</cite>.
  3005      *
  3006      * @return  a string that has the same contents as this string, but is
  3007      *          guaranteed to be from a pool of unique strings.
  3008      */
  3009     public native String intern();
  3010 }