/*

  * Copyright (c) 1994, 2009, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package java.lang;

 /**

  * The {@code Long} class wraps a value of the primitive type {@code

  * long} in an object. An object of type {@code Long} contains a

  * single field whose type is {@code long}.

  *

  * <p> In addition, this class provides several methods for converting

  * a {@code long} to a {@code String} and a {@code String} to a {@code

  * long}, as well as other constants and methods useful when dealing

  * with a {@code long}.

  *

  * <p>Implementation note: The implementations of the "bit twiddling"

  * methods (such as {@link #highestOneBit(long) highestOneBit} and

  * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are

  * based on material from Henry S. Warren, Jr.'s <i>Hacker's

  * Delight</i>, (Addison Wesley, 2002).

  *

  * @author  Lee Boynton

  * @author  Arthur van Hoff

  * @author  Josh Bloch

  * @author  Joseph D. Darcy

  * @since   JDK1.0

  */

 public final class Long extends Number implements Comparable<Long> {

     /**

      * A constant holding the minimum value a {@code long} can

      * have, -2<sup>63</sup>.

      */

     public static final long MIN_VALUE = 0x8000000000000000L;

     /**

      * A constant holding the maximum value a {@code long} can

      * have, 2<sup>63</sup>-1.

      */

     public static final long MAX_VALUE = 0x7fffffffffffffffL;

     /**

      * The {@code Class} instance representing the primitive type

      * {@code long}.

      *

      * @since   JDK1.1

      */

     public static final Class<Long>     TYPE = (Class<Long>) Class.getPrimitiveClass("long");

     /**

      * Returns a string representation of the first argument in the

      * radix specified by the second argument.

      *

      * <p>If the radix is smaller than {@code Character.MIN_RADIX}

      * or larger than {@code Character.MAX_RADIX}, then the radix

      * {@code 10} is used instead.

      *

      * <p>If the first argument is negative, the first element of the

      * result is the ASCII minus sign {@code '-'}

      * (<code>'&#92;u002d'</code>). If the first argument is not

      * negative, no sign character appears in the result.

      *

      * <p>The remaining characters of the result represent the magnitude

      * of the first argument. If the magnitude is zero, it is

      * represented by a single zero character {@code '0'}

      * (<code>'&#92;u0030'</code>); otherwise, the first character of

      * the representation of the magnitude will not be the zero

      * character.  The following ASCII characters are used as digits:

      *

      * <blockquote>

      *   {@code 0123456789abcdefghijklmnopqrstuvwxyz}

      * </blockquote>

      *

      * These are <code>'&#92;u0030'</code> through

      * <code>'&#92;u0039'</code> and <code>'&#92;u0061'</code> through

      * <code>'&#92;u007a'</code>. If {@code radix} is

      * <var>N</var>, then the first <var>N</var> of these characters

      * are used as radix-<var>N</var> digits in the order shown. Thus,

      * the digits for hexadecimal (radix 16) are

      * {@code 0123456789abcdef}. If uppercase letters are

      * desired, the {@link java.lang.String#toUpperCase()} method may

      * be called on the result:

      *

      * <blockquote>

      *  {@code Long.toString(n, 16).toUpperCase()}

      * </blockquote>

      *

      * @param   i       a {@code long} to be converted to a string.

      * @param   radix   the radix to use in the string representation.

      * @return  a string representation of the argument in the specified radix.

      * @see     java.lang.Character#MAX_RADIX

      * @see     java.lang.Character#MIN_RADIX

      */

     public static String toString(long i, int radix) {

         if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)

             radix = 10;

         if (radix == 10)

             return toString(i);

         char[] buf = new char[65];

         int charPos = 64;

         boolean negative = (i < 0);

         if (!negative) {

             i = -i;

         }

         while (i <= -radix) {

             buf[charPos--] = Integer.digits[(int)(-(i % radix))];

             i = i / radix;

         }

         buf[charPos] = Integer.digits[(int)(-i)];

         if (negative) {

             buf[--charPos] = '-';

         }

         return new String(buf, charPos, (65 - charPos));

     }

     /**

      * Returns a string representation of the {@code long}

      * argument as an unsigned integer in base 16.

      *

      * <p>The unsigned {@code long} value is the argument plus

      * 2<sup>64</sup> if the argument is negative; otherwise, it is

      * equal to the argument.  This value is converted to a string of

      * ASCII digits in hexadecimal (base 16) with no extra

      * leading {@code 0}s.  If the unsigned magnitude is zero, it

      * is represented by a single zero character {@code '0'}

      * (<code>'&#92;u0030'</code>); otherwise, the first character of

      * the representation of the unsigned magnitude will not be the

      * zero character. The following characters are used as

      * hexadecimal digits:

      *

      * <blockquote>

      *  {@code 0123456789abcdef}

      * </blockquote>

      *

      * These are the characters <code>'&#92;u0030'</code> through

      * <code>'&#92;u0039'</code> and  <code>'&#92;u0061'</code> through

      * <code>'&#92;u0066'</code>.  If uppercase letters are desired,

      * the {@link java.lang.String#toUpperCase()} method may be called

      * on the result:

      *

      * <blockquote>

      *  {@code Long.toHexString(n).toUpperCase()}

      * </blockquote>

      *

      * @param   i   a {@code long} to be converted to a string.

      * @return  the string representation of the unsigned {@code long}

      *          value represented by the argument in hexadecimal

      *          (base 16).

      * @since   JDK 1.0.2

      */

     public static String toHexString(long i) {

         return toUnsignedString(i, 4);

     }

     /**

      * Returns a string representation of the {@code long}

      * argument as an unsigned integer in base 8.

      *

      * <p>The unsigned {@code long} value is the argument plus

      * 2<sup>64</sup> if the argument is negative; otherwise, it is

      * equal to the argument.  This value is converted to a string of

      * ASCII digits in octal (base 8) with no extra leading

      * {@code 0}s.

      *

      * <p>If the unsigned magnitude is zero, it is represented by a

      * single zero character {@code '0'}

      * (<code>'&#92;u0030'</code>); otherwise, the first character of

      * the representation of the unsigned magnitude will not be the

      * zero character. The following characters are used as octal

      * digits:

      *

      * <blockquote>

      *  {@code 01234567}

      * </blockquote>

      *

      * These are the characters <code>'&#92;u0030'</code> through

      * <code>'&#92;u0037'</code>.

      *

      * @param   i   a {@code long} to be converted to a string.

      * @return  the string representation of the unsigned {@code long}

      *          value represented by the argument in octal (base 8).

      * @since   JDK 1.0.2

      */

     public static String toOctalString(long i) {

         return toUnsignedString(i, 3);

     }

     /**

      * Returns a string representation of the {@code long}

      * argument as an unsigned integer in base 2.

      *

      * <p>The unsigned {@code long} value is the argument plus

      * 2<sup>64</sup> if the argument is negative; otherwise, it is

      * equal to the argument.  This value is converted to a string of

      * ASCII digits in binary (base 2) with no extra leading

      * {@code 0}s.  If the unsigned magnitude is zero, it is

      * represented by a single zero character {@code '0'}

      * (<code>'&#92;u0030'</code>); otherwise, the first character of

      * the representation of the unsigned magnitude will not be the

      * zero character. The characters {@code '0'}

      * (<code>'&#92;u0030'</code>) and {@code '1'}

      * (<code>'&#92;u0031'</code>) are used as binary digits.

      *

      * @param   i   a {@code long} to be converted to a string.

      * @return  the string representation of the unsigned {@code long}

      *          value represented by the argument in binary (base 2).

      * @since   JDK 1.0.2

      */

     public static String toBinaryString(long i) {

         return toUnsignedString(i, 1);

     }

     /**

      * Convert the integer to an unsigned number.

      */

     private static String toUnsignedString(long i, int shift) {

         char[] buf = new char[64];

         int charPos = 64;

         int radix = 1 << shift;

         long mask = radix - 1;

         do {

             buf[--charPos] = Integer.digits[(int)(i & mask)];

             i >>>= shift;

         } while (i != 0);

         return new String(buf, charPos, (64 - charPos));

     }

     /**

      * Returns a {@code String} object representing the specified

      * {@code long}.  The argument is converted to signed decimal

      * representation and returned as a string, exactly as if the

      * argument and the radix 10 were given as arguments to the {@link

      * #toString(long, int)} method.

      *

      * @param   i   a {@code long} to be converted.

      * @return  a string representation of the argument in base 10.

      */

     public static String toString(long i) {

         if (i == Long.MIN_VALUE)

             return "-9223372036854775808";

         int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);

         char[] buf = new char[size];

         getChars(i, size, buf);

         return new String(0, size, buf);

     }

     /**

      * Places characters representing the integer i into the

      * character array buf. The characters are placed into

      * the buffer backwards starting with the least significant

      * digit at the specified index (exclusive), and working

      * backwards from there.

      *

      * Will fail if i == Long.MIN_VALUE

      */

     static void getChars(long i, int index, char[] buf) {

         long q;

         int r;

         int charPos = index;

         char sign = 0;

         if (i < 0) {

             sign = '-';

             i = -i;

         }

         // Get 2 digits/iteration using longs until quotient fits into an int

         while (i > Integer.MAX_VALUE) {

             q = i / 100;

             // really: r = i - (q * 100);

             r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));

             i = q;

             buf[--charPos] = Integer.DigitOnes[r];

             buf[--charPos] = Integer.DigitTens[r];

         }

         // Get 2 digits/iteration using ints

         int q2;

         int i2 = (int)i;

         while (i2 >= 65536) {

             q2 = i2 / 100;

             // really: r = i2 - (q * 100);

             r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));

             i2 = q2;

             buf[--charPos] = Integer.DigitOnes[r];

             buf[--charPos] = Integer.DigitTens[r];

         }

         // Fall thru to fast mode for smaller numbers

         // assert(i2 <= 65536, i2);

         for (;;) {

             q2 = (i2 * 52429) >>> (16+3);

             r = i2 - ((q2 << 3) + (q2 << 1));  // r = i2-(q2*10) ...

             buf[--charPos] = Integer.digits[r];

             i2 = q2;

             if (i2 == 0) break;

         }

         if (sign != 0) {

             buf[--charPos] = sign;

         }

     }

     // Requires positive x

     static int stringSize(long x) {

         long p = 10;

         for (int i=1; i<19; i++) {

             if (x < p)

                 return i;

             p = 10*p;

         }

         return 19;

     }

     /**

      * Parses the string argument as a signed {@code long} in the

      * radix specified by the second argument. The characters in the

      * string must all be digits of the specified radix (as determined

      * by whether {@link java.lang.Character#digit(char, int)} returns

      * a nonnegative value), except that the first character may be an

      * ASCII minus sign {@code '-'} (<code>'&#92;u002D'</code>) to

      * indicate a negative value or an ASCII plus sign {@code '+'}

      * (<code>'&#92;u002B'</code>) to indicate a positive value. The

      * resulting {@code long} value is returned.

      *

      * <p>Note that neither the character {@code L}

      * (<code>'&#92;u004C'</code>) nor {@code l}

      * (<code>'&#92;u006C'</code>) is permitted to appear at the end

      * of the string as a type indicator, as would be permitted in

      * Java programming language source code - except that either

      * {@code L} or {@code l} may appear as a digit for a

      * radix greater than 22.

      *

      * <p>An exception of type {@code NumberFormatException} is

      * thrown if any of the following situations occurs:

      * <ul>

      *

      * <li>The first argument is {@code null} or is a string of

      * length zero.

      *

      * <li>The {@code radix} is either smaller than {@link

      * java.lang.Character#MIN_RADIX} or larger than {@link

      * java.lang.Character#MAX_RADIX}.

      *

      * <li>Any character of the string is not a digit of the specified

      * radix, except that the first character may be a minus sign

      * {@code '-'} (<code>'&#92;u002d'</code>) or plus sign {@code

      * '+'} (<code>'&#92;u002B'</code>) provided that the string is

      * longer than length 1.

      *

      * <li>The value represented by the string is not a value of type

      *      {@code long}.

      * </ul>

      *

      * <p>Examples:

      * <blockquote><pre>

      * parseLong("0", 10) returns 0L

      * parseLong("473", 10) returns 473L

      * parseLong("+42", 10) returns 42L

      * parseLong("-0", 10) returns 0L

      * parseLong("-FF", 16) returns -255L

      * parseLong("1100110", 2) returns 102L

      * parseLong("99", 8) throws a NumberFormatException

      * parseLong("Hazelnut", 10) throws a NumberFormatException

      * parseLong("Hazelnut", 36) returns 1356099454469L

      * </pre></blockquote>

      *

      * @param      s       the {@code String} containing the

      *                     {@code long} representation to be parsed.

      * @param      radix   the radix to be used while parsing {@code s}.

      * @return     the {@code long} represented by the string argument in

      *             the specified radix.

      * @throws     NumberFormatException  if the string does not contain a

      *             parsable {@code long}.

      */

     public static long parseLong(String s, int radix)

               throws NumberFormatException

     {

         if (s == null) {

             throw new NumberFormatException("null");

         }

         if (radix < Character.MIN_RADIX) {

             throw new NumberFormatException("radix " + radix +

                                             " less than Character.MIN_RADIX");

         }

         if (radix > Character.MAX_RADIX) {

             throw new NumberFormatException("radix " + radix +

                                             " greater than Character.MAX_RADIX");

         }

         long result = 0;

         boolean negative = false;

         int i = 0, len = s.length();

         long limit = -Long.MAX_VALUE;

         long multmin;

         int digit;

         if (len > 0) {

             char firstChar = s.charAt(0);

             if (firstChar < '0') { // Possible leading "+" or "-"

                 if (firstChar == '-') {

                     negative = true;

                     limit = Long.MIN_VALUE;

                 } else if (firstChar != '+')

                     throw NumberFormatException.forInputString(s);

                 if (len == 1) // Cannot have lone "+" or "-"

                     throw NumberFormatException.forInputString(s);

                 i++;

             }

             multmin = limit / radix;

             while (i < len) {

                 // Accumulating negatively avoids surprises near MAX_VALUE

                 digit = Character.digit(s.charAt(i++),radix);

                 if (digit < 0) {

                     throw NumberFormatException.forInputString(s);

                 }

                 if (result < multmin) {

                     throw NumberFormatException.forInputString(s);

                 }

                 result *= radix;

                 if (result < limit + digit) {

                     throw NumberFormatException.forInputString(s);

                 }

                 result -= digit;

             }

         } else {

             throw NumberFormatException.forInputString(s);

         }

         return negative ? result : -result;

     }

     /**

      * Parses the string argument as a signed decimal {@code long}.

      * The characters in the string must all be decimal digits, except

      * that the first character may be an ASCII minus sign {@code '-'}

      * (<code>&#92;u002D'</code>) to indicate a negative value or an

      * ASCII plus sign {@code '+'} (<code>'&#92;u002B'</code>) to

      * indicate a positive value. The resulting {@code long} value is

      * returned, exactly as if the argument and the radix {@code 10}

      * were given as arguments to the {@link

      * #parseLong(java.lang.String, int)} method.

      *

      * <p>Note that neither the character {@code L}

      * (<code>'&#92;u004C'</code>) nor {@code l}

      * (<code>'&#92;u006C'</code>) is permitted to appear at the end

      * of the string as a type indicator, as would be permitted in

      * Java programming language source code.

      *

      * @param      s   a {@code String} containing the {@code long}

      *             representation to be parsed

      * @return     the {@code long} represented by the argument in

      *             decimal.

      * @throws     NumberFormatException  if the string does not contain a

      *             parsable {@code long}.

      */

     public static long parseLong(String s) throws NumberFormatException {

         return parseLong(s, 10);

     }

     /**

      * Returns a {@code Long} object holding the value

      * extracted from the specified {@code String} when parsed

      * with the radix given by the second argument.  The first

      * argument is interpreted as representing a signed

      * {@code long} in the radix specified by the second

      * argument, exactly as if the arguments were given to the {@link

      * #parseLong(java.lang.String, int)} method. The result is a

      * {@code Long} object that represents the {@code long}

      * value specified by the string.

      *

      * <p>In other words, this method returns a {@code Long} object equal

      * to the value of:

      *

      * <blockquote>

      *  {@code new Long(Long.parseLong(s, radix))}

      * </blockquote>

      *

      * @param      s       the string to be parsed

      * @param      radix   the radix to be used in interpreting {@code s}

      * @return     a {@code Long} object holding the value

      *             represented by the string argument in the specified

      *             radix.

      * @throws     NumberFormatException  If the {@code String} does not

      *             contain a parsable {@code long}.

      */

     public static Long valueOf(String s, int radix) throws NumberFormatException {

         return Long.valueOf(parseLong(s, radix));

     }

     /**

      * Returns a {@code Long} object holding the value

      * of the specified {@code String}. The argument is

      * interpreted as representing a signed decimal {@code long},

      * exactly as if the argument were given to the {@link

      * #parseLong(java.lang.String)} method. The result is a

      * {@code Long} object that represents the integer value

      * specified by the string.

      *

      * <p>In other words, this method returns a {@code Long} object

      * equal to the value of:

      *

      * <blockquote>

      *  {@code new Long(Long.parseLong(s))}

      * </blockquote>

      *

      * @param      s   the string to be parsed.

      * @return     a {@code Long} object holding the value

      *             represented by the string argument.

      * @throws     NumberFormatException  If the string cannot be parsed

      *             as a {@code long}.

      */

     public static Long valueOf(String s) throws NumberFormatException

     {

         return Long.valueOf(parseLong(s, 10));

     }

     private static class LongCache {

         private LongCache(){}

         static final Long cache[] = new Long[-(-128) + 127 + 1];

         static {

             for(int i = 0; i < cache.length; i++)

                 cache[i] = new Long(i - 128);

         }

     }

     /**

      * Returns a {@code Long} instance representing the specified

      * {@code long} value.

      * If a new {@code Long} instance is not required, this method

      * should generally be used in preference to the constructor

      * {@link #Long(long)}, as this method is likely to yield

      * significantly better space and time performance by caching

      * frequently requested values.

      *

      * Note that unlike the {@linkplain Integer#valueOf(int)

      * corresponding method} in the {@code Integer} class, this method

      * is <em>not</em> required to cache values within a particular

      * range.

      *

      * @param  l a long value.

      * @return a {@code Long} instance representing {@code l}.

      * @since  1.5

      */

     public static Long valueOf(long l) {

         final int offset = 128;

         if (l >= -128 && l <= 127) { // will cache

             return LongCache.cache[(int)l + offset];

         }

         return new Long(l);

     }

     /**

      * Decodes a {@code String} into a {@code Long}.

      * Accepts decimal, hexadecimal, and octal numbers given by the

      * following grammar:

      *

      * <blockquote>

      * <dl>

      * <dt><i>DecodableString:</i>

      * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>

      * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>

      * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>

      * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>

      * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>

      * <p>

      * <dt><i>Sign:</i>

      * <dd>{@code -}

      * <dd>{@code +}

      * </dl>

      * </blockquote>

      *

      * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>

      * are as defined in section 3.10.1 of

      * <cite>The Java&trade; Language Specification</cite>,

      * except that underscores are not accepted between digits.

      *

      * <p>The sequence of characters following an optional

      * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",

      * "{@code #}", or leading zero) is parsed as by the {@code

      * Long.parseLong} method with the indicated radix (10, 16, or 8).

      * This sequence of characters must represent a positive value or

      * a {@link NumberFormatException} will be thrown.  The result is

      * negated if first character of the specified {@code String} is

      * the minus sign.  No whitespace characters are permitted in the

      * {@code String}.

      *

      * @param     nm the {@code String} to decode.

      * @return    a {@code Long} object holding the {@code long}

      *            value represented by {@code nm}

      * @throws    NumberFormatException  if the {@code String} does not

      *            contain a parsable {@code long}.

      * @see java.lang.Long#parseLong(String, int)

      * @since 1.2

      */

     public static Long decode(String nm) throws NumberFormatException {

         int radix = 10;

         int index = 0;

         boolean negative = false;

         Long result;

         if (nm.length() == 0)

             throw new NumberFormatException("Zero length string");

         char firstChar = nm.charAt(0);

         // Handle sign, if present

         if (firstChar == '-') {

             negative = true;

             index++;

         } else if (firstChar == '+')

             index++;

         // Handle radix specifier, if present

         if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {

             index += 2;

             radix = 16;

         }

         else if (nm.startsWith("#", index)) {

             index ++;

             radix = 16;

         }

         else if (nm.startsWith("0", index) && nm.length() > 1 + index) {

             index ++;

             radix = 8;

         }

         if (nm.startsWith("-", index) || nm.startsWith("+", index))

             throw new NumberFormatException("Sign character in wrong position");

         try {

             result = Long.valueOf(nm.substring(index), radix);

             result = negative ? Long.valueOf(-result.longValue()) : result;

         } catch (NumberFormatException e) {

             // If number is Long.MIN_VALUE, we'll end up here. The next line

             // handles this case, and causes any genuine format error to be

             // rethrown.

             String constant = negative ? ("-" + nm.substring(index))

                                        : nm.substring(index);

             result = Long.valueOf(constant, radix);

         }

         return result;

     }

     /**

      * The value of the {@code Long}.

      *

      * @serial

      */

     private final long value;

     /**

      * Constructs a newly allocated {@code Long} object that

      * represents the specified {@code long} argument.

      *

      * @param   value   the value to be represented by the

      *          {@code Long} object.

      */

     public Long(long value) {

         this.value = value;

     }

     /**

      * Constructs a newly allocated {@code Long} object that

      * represents the {@code long} value indicated by the

      * {@code String} parameter. The string is converted to a

      * {@code long} value in exactly the manner used by the

      * {@code parseLong} method for radix 10.

      *

      * @param      s   the {@code String} to be converted to a

      *             {@code Long}.

      * @throws     NumberFormatException  if the {@code String} does not

      *             contain a parsable {@code long}.

      * @see        java.lang.Long#parseLong(java.lang.String, int)

      */

     public Long(String s) throws NumberFormatException {

         this.value = parseLong(s, 10);

     }

     /**

      * Returns the value of this {@code Long} as a

      * {@code byte}.

      */

     public byte byteValue() {

         return (byte)value;

     }

     /**

      * Returns the value of this {@code Long} as a

      * {@code short}.

      */

     public short shortValue() {

         return (short)value;

     }

     /**

      * Returns the value of this {@code Long} as an

      * {@code int}.

      */

     public int intValue() {

         return (int)value;

     }

     /**

      * Returns the value of this {@code Long} as a

      * {@code long} value.

      */

     public long longValue() {

         return (long)value;

     }

     /**

      * Returns the value of this {@code Long} as a

      * {@code float}.

      */

     public float floatValue() {

         return (float)value;

     }

     /**

      * Returns the value of this {@code Long} as a

      * {@code double}.

      */

     public double doubleValue() {

         return (double)value;

     }

     /**

      * Returns a {@code String} object representing this

      * {@code Long}'s value.  The value is converted to signed

      * decimal representation and returned as a string, exactly as if

      * the {@code long} value were given as an argument to the

      * {@link java.lang.Long#toString(long)} method.

      *

      * @return  a string representation of the value of this object in

      *          base 10.

      */

     public String toString() {

         return toString(value);

     }

     /**

      * Returns a hash code for this {@code Long}. The result is

      * the exclusive OR of the two halves of the primitive

      * {@code long} value held by this {@code Long}

      * object. That is, the hashcode is the value of the expression:

      *

      * <blockquote>

      *  {@code (int)(this.longValue()^(this.longValue()>>>32))}

      * </blockquote>

      *

      * @return  a hash code value for this object.

      */

     public int hashCode() {

         return (int)(value ^ (value >>> 32));

     }

     /**

      * Compares this object to the specified object.  The result is

      * {@code true} if and only if the argument is not

      * {@code null} and is a {@code Long} object that

      * contains the same {@code long} value as this object.

      *

      * @param   obj   the object to compare with.

      * @return  {@code true} if the objects are the same;

      *          {@code false} otherwise.

      */

     public boolean equals(Object obj) {

         if (obj instanceof Long) {

             return value == ((Long)obj).longValue();

         }

         return false;

     }

     /**

      * Determines the {@code long} value of the system property

      * with the specified name.

      *

      * <p>The first argument is treated as the name of a system property.

      * System properties are accessible through the {@link

      * java.lang.System#getProperty(java.lang.String)} method. The

      * string value of this property is then interpreted as a

      * {@code long} value and a {@code Long} object

      * representing this value is returned.  Details of possible

      * numeric formats can be found with the definition of

      * {@code getProperty}.

      *

      * <p>If there is no property with the specified name, if the

      * specified name is empty or {@code null}, or if the

      * property does not have the correct numeric format, then

      * {@code null} is returned.

      *

      * <p>In other words, this method returns a {@code Long} object equal to

      * the value of:

      *

      * <blockquote>

      *  {@code getLong(nm, null)}

      * </blockquote>

      *

      * @param   nm   property name.

      * @return  the {@code Long} value of the property.

      * @see     java.lang.System#getProperty(java.lang.String)

      * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)

      */

     public static Long getLong(String nm) {

         return getLong(nm, null);

     }

     /**

      * Determines the {@code long} value of the system property

      * with the specified name.

      *

      * <p>The first argument is treated as the name of a system property.

      * System properties are accessible through the {@link

      * java.lang.System#getProperty(java.lang.String)} method. The

      * string value of this property is then interpreted as a

      * {@code long} value and a {@code Long} object

      * representing this value is returned.  Details of possible

      * numeric formats can be found with the definition of

      * {@code getProperty}.

      *

      * <p>The second argument is the default value. A {@code Long} object

      * that represents the value of the second argument is returned if there

      * is no property of the specified name, if the property does not have

      * the correct numeric format, or if the specified name is empty or null.

      *

      * <p>In other words, this method returns a {@code Long} object equal

      * to the value of:

      *

      * <blockquote>

      *  {@code getLong(nm, new Long(val))}

      * </blockquote>

      *

      * but in practice it may be implemented in a manner such as:

      *

      * <blockquote><pre>

      * Long result = getLong(nm, null);

      * return (result == null) ? new Long(val) : result;

      * </pre></blockquote>

      *

      * to avoid the unnecessary allocation of a {@code Long} object when

      * the default value is not needed.

      *

      * @param   nm    property name.

      * @param   val   default value.

      * @return  the {@code Long} value of the property.

      * @see     java.lang.System#getProperty(java.lang.String)

      * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)

      */

     public static Long getLong(String nm, long val) {

         Long result = Long.getLong(nm, null);

         return (result == null) ? Long.valueOf(val) : result;

     }

     /**

      * Returns the {@code long} value of the system property with

      * the specified name.  The first argument is treated as the name

      * of a system property.  System properties are accessible through

      * the {@link java.lang.System#getProperty(java.lang.String)}

      * method. The string value of this property is then interpreted

      * as a {@code long} value, as per the

      * {@code Long.decode} method, and a {@code Long} object

      * representing this value is returned.

      *

      * <ul>

      * <li>If the property value begins with the two ASCII characters

      * {@code 0x} or the ASCII character {@code #}, not followed by

      * a minus sign, then the rest of it is parsed as a hexadecimal integer

      * exactly as for the method {@link #valueOf(java.lang.String, int)}

      * with radix 16.

      * <li>If the property value begins with the ASCII character

      * {@code 0} followed by another character, it is parsed as

      * an octal integer exactly as by the method {@link

      * #valueOf(java.lang.String, int)} with radix 8.

      * <li>Otherwise the property value is parsed as a decimal

      * integer exactly as by the method

      * {@link #valueOf(java.lang.String, int)} with radix 10.

      * </ul>

      *

      * <p>Note that, in every case, neither {@code L}

      * (<code>'&#92;u004C'</code>) nor {@code l}

      * (<code>'&#92;u006C'</code>) is permitted to appear at the end

      * of the property value as a type indicator, as would be

      * permitted in Java programming language source code.

      *

      * <p>The second argument is the default value. The default value is

      * returned if there is no property of the specified name, if the

      * property does not have the correct numeric format, or if the

      * specified name is empty or {@code null}.

      *

      * @param   nm   property name.

      * @param   val   default value.

      * @return  the {@code Long} value of the property.

      * @see     java.lang.System#getProperty(java.lang.String)

      * @see java.lang.System#getProperty(java.lang.String, java.lang.String)

      * @see java.lang.Long#decode

      */

     public static Long getLong(String nm, Long val) {

         String v = null;

         try {

             v = AbstractStringBuilder.getProperty(nm);

         } catch (IllegalArgumentException e) {

         } catch (NullPointerException e) {

         }

         if (v != null) {

             try {

                 return Long.decode(v);

             } catch (NumberFormatException e) {

             }

         }

         return val;

     }

     /**

      * Compares two {@code Long} objects numerically.

      *

      * @param   anotherLong   the {@code Long} to be compared.

      * @return  the value {@code 0} if this {@code Long} is

      *          equal to the argument {@code Long}; a value less than

      *          {@code 0} if this {@code Long} is numerically less

      *          than the argument {@code Long}; and a value greater

      *          than {@code 0} if this {@code Long} is numerically

      *           greater than the argument {@code Long} (signed

      *           comparison).

      * @since   1.2

      */

     public int compareTo(Long anotherLong) {

         return compare(this.value, anotherLong.value);

     }

     /**

      * Compares two {@code long} values numerically.

      * The value returned is identical to what would be returned by:

      * <pre>

      *    Long.valueOf(x).compareTo(Long.valueOf(y))

      * </pre>

      *

      * @param  x the first {@code long} to compare

      * @param  y the second {@code long} to compare

      * @return the value {@code 0} if {@code x == y};

      *         a value less than {@code 0} if {@code x < y}; and

      *         a value greater than {@code 0} if {@code x > y}

      * @since 1.7

      */

     public static int compare(long x, long y) {

         return (x < y) ? -1 : ((x == y) ? 0 : 1);

     }

     // Bit Twiddling

     /**

      * The number of bits used to represent a {@code long} value in two's

      * complement binary form.

      *

      * @since 1.5

      */

     public static final int SIZE = 64;

     /**

      * Returns a {@code long} value with at most a single one-bit, in the

      * position of the highest-order ("leftmost") one-bit in the specified

      * {@code long} value.  Returns zero if the specified value has no

      * one-bits in its two's complement binary representation, that is, if it

      * is equal to zero.

      *

      * @return a {@code long} value with a single one-bit, in the position

      *     of the highest-order one-bit in the specified value, or zero if

      *     the specified value is itself equal to zero.

      * @since 1.5

      */

     public static long highestOneBit(long i) {

         // HD, Figure 3-1

         i |= (i >>  1);

         i |= (i >>  2);

         i |= (i >>  4);

         i |= (i >>  8);

         i |= (i >> 16);

         i |= (i >> 32);

         return i - (i >>> 1);

     }

     /**

      * Returns a {@code long} value with at most a single one-bit, in the

      * position of the lowest-order ("rightmost") one-bit in the specified

      * {@code long} value.  Returns zero if the specified value has no

      * one-bits in its two's complement binary representation, that is, if it

      * is equal to zero.

      *

      * @return a {@code long} value with a single one-bit, in the position

      *     of the lowest-order one-bit in the specified value, or zero if

      *     the specified value is itself equal to zero.

      * @since 1.5

      */

     public static long lowestOneBit(long i) {

         // HD, Section 2-1

         return i & -i;

     }

     /**

      * Returns the number of zero bits preceding the highest-order

      * ("leftmost") one-bit in the two's complement binary representation

      * of the specified {@code long} value.  Returns 64 if the

      * specified value has no one-bits in its two's complement representation,

      * in other words if it is equal to zero.

      *

      * <p>Note that this method is closely related to the logarithm base 2.

      * For all positive {@code long} values x:

      * <ul>

      * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}

      * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}

      * </ul>

      *

      * @return the number of zero bits preceding the highest-order

      *     ("leftmost") one-bit in the two's complement binary representation

      *     of the specified {@code long} value, or 64 if the value

      *     is equal to zero.

      * @since 1.5

      */

     public static int numberOfLeadingZeros(long i) {

         // HD, Figure 5-6

          if (i == 0)

             return 64;

         int n = 1;

         int x = (int)(i >>> 32);

         if (x == 0) { n += 32; x = (int)i; }

         if (x >>> 16 == 0) { n += 16; x <<= 16; }

         if (x >>> 24 == 0) { n +=  8; x <<=  8; }

         if (x >>> 28 == 0) { n +=  4; x <<=  4; }

         if (x >>> 30 == 0) { n +=  2; x <<=  2; }

         n -= x >>> 31;

         return n;

     }

     /**

      * Returns the number of zero bits following the lowest-order ("rightmost")

      * one-bit in the two's complement binary representation of the specified

      * {@code long} value.  Returns 64 if the specified value has no

      * one-bits in its two's complement representation, in other words if it is

      * equal to zero.

      *

      * @return the number of zero bits following the lowest-order ("rightmost")

      *     one-bit in the two's complement binary representation of the

      *     specified {@code long} value, or 64 if the value is equal

      *     to zero.

      * @since 1.5

      */

     public static int numberOfTrailingZeros(long i) {

         // HD, Figure 5-14

         int x, y;

         if (i == 0) return 64;

         int n = 63;

         y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);

         y = x <<16; if (y != 0) { n = n -16; x = y; }

         y = x << 8; if (y != 0) { n = n - 8; x = y; }

         y = x << 4; if (y != 0) { n = n - 4; x = y; }

         y = x << 2; if (y != 0) { n = n - 2; x = y; }

         return n - ((x << 1) >>> 31);

     }

     /**

      * Returns the number of one-bits in the two's complement binary

      * representation of the specified {@code long} value.  This function is

      * sometimes referred to as the <i>population count</i>.

      *

      * @return the number of one-bits in the two's complement binary

      *     representation of the specified {@code long} value.

      * @since 1.5

      */

      public static int bitCount(long i) {

         // HD, Figure 5-14

         i = i - ((i >>> 1) & 0x5555555555555555L);

         i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);

         i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;

         i = i + (i >>> 8);

         i = i + (i >>> 16);

         i = i + (i >>> 32);

         return (int)i & 0x7f;

      }

     /**

      * Returns the value obtained by rotating the two's complement binary

      * representation of the specified {@code long} value left by the

      * specified number of bits.  (Bits shifted out of the left hand, or

      * high-order, side reenter on the right, or low-order.)

      *

      * <p>Note that left rotation with a negative distance is equivalent to

      * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,

      * distance)}.  Note also that rotation by any multiple of 64 is a

      * no-op, so all but the last six bits of the rotation distance can be

      * ignored, even if the distance is negative: {@code rotateLeft(val,

      * distance) == rotateLeft(val, distance & 0x3F)}.

      *

      * @return the value obtained by rotating the two's complement binary

      *     representation of the specified {@code long} value left by the

      *     specified number of bits.

      * @since 1.5

      */

     public static long rotateLeft(long i, int distance) {

         return (i << distance) | (i >>> -distance);

     }

     /**

      * Returns the value obtained by rotating the two's complement binary

      * representation of the specified {@code long} value right by the

      * specified number of bits.  (Bits shifted out of the right hand, or

      * low-order, side reenter on the left, or high-order.)

      *

      * <p>Note that right rotation with a negative distance is equivalent to

      * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,

      * distance)}.  Note also that rotation by any multiple of 64 is a

      * no-op, so all but the last six bits of the rotation distance can be

      * ignored, even if the distance is negative: {@code rotateRight(val,

      * distance) == rotateRight(val, distance & 0x3F)}.

      *

      * @return the value obtained by rotating the two's complement binary

      *     representation of the specified {@code long} value right by the

      *     specified number of bits.

      * @since 1.5

      */

     public static long rotateRight(long i, int distance) {

         return (i >>> distance) | (i << -distance);

     }

     /**

      * Returns the value obtained by reversing the order of the bits in the

      * two's complement binary representation of the specified {@code long}

      * value.

      *

      * @return the value obtained by reversing order of the bits in the

      *     specified {@code long} value.

      * @since 1.5

      */

     public static long reverse(long i) {

         // HD, Figure 7-1

         i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;

         i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;

         i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;

         i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;

         i = (i << 48) | ((i & 0xffff0000L) << 16) |

             ((i >>> 16) & 0xffff0000L) | (i >>> 48);

         return i;

     }

     /**

      * Returns the signum function of the specified {@code long} value.  (The

      * return value is -1 if the specified value is negative; 0 if the

      * specified value is zero; and 1 if the specified value is positive.)

      *

      * @return the signum function of the specified {@code long} value.

      * @since 1.5

      */

     public static int signum(long i) {

         // HD, Section 2-7

         return (int) ((i >> 63) | (-i >>> 63));

     }

     /**

      * Returns the value obtained by reversing the order of the bytes in the

      * two's complement representation of the specified {@code long} value.

      *

      * @return the value obtained by reversing the bytes in the specified

      *     {@code long} value.

      * @since 1.5

      */

     public static long reverseBytes(long i) {

         i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;

         return (i << 48) | ((i & 0xffff0000L) << 16) |

             ((i >>> 16) & 0xffff0000L) | (i >>> 48);

     }

     /** use serialVersionUID from JDK 1.0.2 for interoperability */

     private static final long serialVersionUID = 4290774380558885855L;

 }