/*

 * Copyright (c) 1994, 2010, 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;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

/**

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

 * {@code double} in an object. An object of type

 * {@code Double} contains a single field whose type is

 * {@code double}.

 *

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

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

 * {@code String} to a {@code double}, as well as other

 * constants and methods useful when dealing with a

 * {@code double}.

 *

 * @author  Lee Boynton

 * @author  Arthur van Hoff

 * @author  Joseph D. Darcy

 * @since JDK1.0

 */

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

    /**

     * A constant holding the positive infinity of type

     * {@code double}. It is equal to the value returned by

     * {@code Double.longBitsToDouble(0x7ff0000000000000L)}.

     */

    public static final double POSITIVE_INFINITY = 1.0 / 0.0;

    /**

     * A constant holding the negative infinity of type

     * {@code double}. It is equal to the value returned by

     * {@code Double.longBitsToDouble(0xfff0000000000000L)}.

     */

    public static final double NEGATIVE_INFINITY = -1.0 / 0.0;

    /**

     * A constant holding a Not-a-Number (NaN) value of type

     * {@code double}. It is equivalent to the value returned by

     * {@code Double.longBitsToDouble(0x7ff8000000000000L)}.

     */

    public static final double NaN = 0.0d / 0.0;

    /**

     * A constant holding the largest positive finite value of type

     * {@code double},

     * (2-2<sup>-52</sup>)&middot;2<sup>1023</sup>.  It is equal to

     * the hexadecimal floating-point literal

     * {@code 0x1.fffffffffffffP+1023} and also equal to

     * {@code Double.longBitsToDouble(0x7fefffffffffffffL)}.

     */

    public static final double MAX_VALUE = 0x1.fffffffffffffP+1023; // 1.7976931348623157e+308

    /**

     * A constant holding the smallest positive normal value of type

     * {@code double}, 2<sup>-1022</sup>.  It is equal to the

     * hexadecimal floating-point literal {@code 0x1.0p-1022} and also

     * equal to {@code Double.longBitsToDouble(0x0010000000000000L)}.

     *

     * @since 1.6

     */

    public static final double MIN_NORMAL = 0x1.0p-1022; // 2.2250738585072014E-308

    /**

     * A constant holding the smallest positive nonzero value of type

     * {@code double}, 2<sup>-1074</sup>. It is equal to the

     * hexadecimal floating-point literal

     * {@code 0x0.0000000000001P-1022} and also equal to

     * {@code Double.longBitsToDouble(0x1L)}.

     */

    public static final double MIN_VALUE = 0x0.0000000000001P-1022; // 4.9e-324

    /**

     * Maximum exponent a finite {@code double} variable may have.

     * It is equal to the value returned by

     * {@code Math.getExponent(Double.MAX_VALUE)}.

     *

     * @since 1.6

     */

    public static final int MAX_EXPONENT = 1023;

    /**

     * Minimum exponent a normalized {@code double} variable may

     * have.  It is equal to the value returned by

     * {@code Math.getExponent(Double.MIN_NORMAL)}.

     *

     * @since 1.6

     */

    public static final int MIN_EXPONENT = -1022;

    /**

     * The number of bits used to represent a {@code double} value.

     *

     * @since 1.5

     */

    public static final int SIZE = 64;

    /**

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

     * {@code double}.

     *

     * @since JDK1.1

     */

    public static final Class<Double>   TYPE = (Class<Double>) Class.getPrimitiveClass("double");

    /**

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

     * argument. All characters mentioned below are ASCII characters.

     * <ul>

     * <li>If the argument is NaN, the result is the string

     *     "{@code NaN}".

     * <li>Otherwise, the result is a string that represents the sign and

     * magnitude (absolute value) of the argument. If the sign is negative,

     * the first character of the result is '{@code -}'

     * (<code>'&#92;u002D'</code>); if the sign is positive, no sign character

     * appears in the result. As for the magnitude <i>m</i>:

     * <ul>

     * <li>If <i>m</i> is infinity, it is represented by the characters

     * {@code "Infinity"}; thus, positive infinity produces the result

     * {@code "Infinity"} and negative infinity produces the result

     * {@code "-Infinity"}.

     *

     * <li>If <i>m</i> is zero, it is represented by the characters

     * {@code "0.0"}; thus, negative zero produces the result

     * {@code "-0.0"} and positive zero produces the result

     * {@code "0.0"}.

     *

     * <li>If <i>m</i> is greater than or equal to 10<sup>-3</sup> but less

     * than 10<sup>7</sup>, then it is represented as the integer part of

     * <i>m</i>, in decimal form with no leading zeroes, followed by

     * '{@code .}' (<code>'&#92;u002E'</code>), followed by one or

     * more decimal digits representing the fractional part of <i>m</i>.

     *

     * <li>If <i>m</i> is less than 10<sup>-3</sup> or greater than or

     * equal to 10<sup>7</sup>, then it is represented in so-called

     * "computerized scientific notation." Let <i>n</i> be the unique

     * integer such that 10<sup><i>n</i></sup> &le; <i>m</i> {@literal <}

     * 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the

     * mathematically exact quotient of <i>m</i> and

     * 10<sup><i>n</i></sup> so that 1 &le; <i>a</i> {@literal <} 10. The

     * magnitude is then represented as the integer part of <i>a</i>,

     * as a single decimal digit, followed by '{@code .}'

     * (<code>'&#92;u002E'</code>), followed by decimal digits

     * representing the fractional part of <i>a</i>, followed by the

     * letter '{@code E}' (<code>'&#92;u0045'</code>), followed

     * by a representation of <i>n</i> as a decimal integer, as

     * produced by the method {@link Integer#toString(int)}.

     * </ul>

     * </ul>

     * How many digits must be printed for the fractional part of

     * <i>m</i> or <i>a</i>? There must be at least one digit to represent

     * the fractional part, and beyond that as many, but only as many, more

     * digits as are needed to uniquely distinguish the argument value from

     * adjacent values of type {@code double}. That is, suppose that

     * <i>x</i> is the exact mathematical value represented by the decimal

     * representation produced by this method for a finite nonzero argument

     * <i>d</i>. Then <i>d</i> must be the {@code double} value nearest

     * to <i>x</i>; or if two {@code double} values are equally close

     * to <i>x</i>, then <i>d</i> must be one of them and the least

     * significant bit of the significand of <i>d</i> must be {@code 0}.

     *

     * <p>To create localized string representations of a floating-point

     * value, use subclasses of {@link java.text.NumberFormat}.

     *

     * @param   d   the {@code double} to be converted.

     * @return a string representation of the argument.

     */

    @JavaScriptBody(args="d", body="var r = d.toString();"

        + "if (isFinite(d) && (r.indexOf('.') === -1)) r = r + '.0';"

        + "return r;")

    public static String toString(double d) {

        throw new UnsupportedOperationException();

    }

    /**

     * Returns a hexadecimal string representation of the

     * {@code double} argument. All characters mentioned below

     * are ASCII characters.

     *

     * <ul>

     * <li>If the argument is NaN, the result is the string

     *     "{@code NaN}".

     * <li>Otherwise, the result is a string that represents the sign

     * and magnitude of the argument. If the sign is negative, the

     * first character of the result is '{@code -}'

     * (<code>'&#92;u002D'</code>); if the sign is positive, no sign

     * character appears in the result. As for the magnitude <i>m</i>:

     *

     * <ul>

     * <li>If <i>m</i> is infinity, it is represented by the string

     * {@code "Infinity"}; thus, positive infinity produces the

     * result {@code "Infinity"} and negative infinity produces

     * the result {@code "-Infinity"}.

     *

     * <li>If <i>m</i> is zero, it is represented by the string

     * {@code "0x0.0p0"}; thus, negative zero produces the result

     * {@code "-0x0.0p0"} and positive zero produces the result

     * {@code "0x0.0p0"}.

     *

     * <li>If <i>m</i> is a {@code double} value with a

     * normalized representation, substrings are used to represent the

     * significand and exponent fields.  The significand is

     * represented by the characters {@code "0x1."}

     * followed by a lowercase hexadecimal representation of the rest

     * of the significand as a fraction.  Trailing zeros in the

     * hexadecimal representation are removed unless all the digits

     * are zero, in which case a single zero is used. Next, the

     * exponent is represented by {@code "p"} followed

     * by a decimal string of the unbiased exponent as if produced by

     * a call to {@link Integer#toString(int) Integer.toString} on the

     * exponent value.

     *

     * <li>If <i>m</i> is a {@code double} value with a subnormal

     * representation, the significand is represented by the

     * characters {@code "0x0."} followed by a

     * hexadecimal representation of the rest of the significand as a

     * fraction.  Trailing zeros in the hexadecimal representation are

     * removed. Next, the exponent is represented by

     * {@code "p-1022"}.  Note that there must be at

     * least one nonzero digit in a subnormal significand.

     *

     * </ul>

     *

     * </ul>

     *

     * <table border>

     * <caption><h3>Examples</h3></caption>

     * <tr><th>Floating-point Value</th><th>Hexadecimal String</th>

     * <tr><td>{@code 1.0}</td> <td>{@code 0x1.0p0}</td>

     * <tr><td>{@code -1.0}</td>        <td>{@code -0x1.0p0}</td>

     * <tr><td>{@code 2.0}</td> <td>{@code 0x1.0p1}</td>

     * <tr><td>{@code 3.0}</td> <td>{@code 0x1.8p1}</td>

     * <tr><td>{@code 0.5}</td> <td>{@code 0x1.0p-1}</td>

     * <tr><td>{@code 0.25}</td>        <td>{@code 0x1.0p-2}</td>

     * <tr><td>{@code Double.MAX_VALUE}</td>

     *     <td>{@code 0x1.fffffffffffffp1023}</td>

     * <tr><td>{@code Minimum Normal Value}</td>

     *     <td>{@code 0x1.0p-1022}</td>

     * <tr><td>{@code Maximum Subnormal Value}</td>

     *     <td>{@code 0x0.fffffffffffffp-1022}</td>

     * <tr><td>{@code Double.MIN_VALUE}</td>

     *     <td>{@code 0x0.0000000000001p-1022}</td>

     * </table>

     * @param   d   the {@code double} to be converted.

     * @return a hex string representation of the argument.

     * @since 1.5

     * @author Joseph D. Darcy

     */

    public static String toHexString(double d) {

        throw new UnsupportedOperationException();

//        /*

//         * Modeled after the "a" conversion specifier in C99, section

//         * 7.19.6.1; however, the output of this method is more

//         * tightly specified.

//         */

//        if (!FpUtils.isFinite(d) )

//            // For infinity and NaN, use the decimal output.

//            return Double.toString(d);

//        else {

//            // Initialized to maximum size of output.

//            StringBuffer answer = new StringBuffer(24);

//

//            if (FpUtils.rawCopySign(1.0, d) == -1.0) // value is negative,

//                answer.append("-");                  // so append sign info

//

//            answer.append("0x");

//

//            d = Math.abs(d);

//

//            if(d == 0.0) {

//                answer.append("0.0p0");

//            }

//            else {

//                boolean subnormal = (d < DoubleConsts.MIN_NORMAL);

//

//                // Isolate significand bits and OR in a high-order bit

//                // so that the string representation has a known

//                // length.

//                long signifBits = (Double.doubleToLongBits(d)

//                                   & DoubleConsts.SIGNIF_BIT_MASK) |

//                    0x1000000000000000L;

//

//                // Subnormal values have a 0 implicit bit; normal

//                // values have a 1 implicit bit.

//                answer.append(subnormal ? "0." : "1.");

//

//                // Isolate the low-order 13 digits of the hex

//                // representation.  If all the digits are zero,

//                // replace with a single 0; otherwise, remove all

//                // trailing zeros.

//                String signif = Long.toHexString(signifBits).substring(3,16);

//                answer.append(signif.equals("0000000000000") ? // 13 zeros

//                              "0":

//                              signif.replaceFirst("0{1,12}$", ""));

//

//                // If the value is subnormal, use the E_min exponent

//                // value for double; otherwise, extract and report d's

//                // exponent (the representation of a subnormal uses

//                // E_min -1).

//                answer.append("p" + (subnormal ?

//                               DoubleConsts.MIN_EXPONENT:

//                               FpUtils.getExponent(d) ));

//            }

//            return answer.toString();

//        }

    }

    /**

     * Returns a {@code Double} object holding the

     * {@code double} value represented by the argument string

     * {@code s}.

     *

     * <p>If {@code s} is {@code null}, then a

     * {@code NullPointerException} is thrown.

     *

     * <p>Leading and trailing whitespace characters in {@code s}

     * are ignored.  Whitespace is removed as if by the {@link

     * String#trim} method; that is, both ASCII space and control

     * characters are removed. The rest of {@code s} should

     * constitute a <i>FloatValue</i> as described by the lexical

     * syntax rules:

     *

     * <blockquote>

     * <dl>

     * <dt><i>FloatValue:</i>

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

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

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

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

     * <dd><i>SignedInteger</i>

     * </dl>

     *

     * <p>

     *

     * <dl>

     * <dt><i>HexFloatingPointLiteral</i>:

     * <dd> <i>HexSignificand BinaryExponent FloatTypeSuffix<sub>opt</sub></i>

     * </dl>

     *

     * <p>

     *

     * <dl>

     * <dt><i>HexSignificand:</i>

     * <dd><i>HexNumeral</i>

     * <dd><i>HexNumeral</i> {@code .}

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

     *     </i>{@code .}<i> HexDigits</i>

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

     *     </i>{@code .} <i>HexDigits</i>

     * </dl>

     *

     * <p>

     *

     * <dl>

     * <dt><i>BinaryExponent:</i>

     * <dd><i>BinaryExponentIndicator SignedInteger</i>

     * </dl>

     *

     * <p>

     *

     * <dl>

     * <dt><i>BinaryExponentIndicator:</i>

     * <dd>{@code p}

     * <dd>{@code P}

     * </dl>

     *

     * </blockquote>

     *

     * where <i>Sign</i>, <i>FloatingPointLiteral</i>,

     * <i>HexNumeral</i>, <i>HexDigits</i>, <i>SignedInteger</i> and

     * <i>FloatTypeSuffix</i> are as defined in the lexical structure

     * sections of

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

     * except that underscores are not accepted between digits.

     * If {@code s} does not have the form of

     * a <i>FloatValue</i>, then a {@code NumberFormatException}

     * is thrown. Otherwise, {@code s} is regarded as

     * representing an exact decimal value in the usual

     * "computerized scientific notation" or as an exact

     * hexadecimal value; this exact numerical value is then

     * conceptually converted to an "infinitely precise"

     * binary value that is then rounded to type {@code double}

     * by the usual round-to-nearest rule of IEEE 754 floating-point

     * arithmetic, which includes preserving the sign of a zero

     * value.

     *

     * Note that the round-to-nearest rule also implies overflow and

     * underflow behaviour; if the exact value of {@code s} is large

     * enough in magnitude (greater than or equal to ({@link

     * #MAX_VALUE} + {@link Math#ulp(double) ulp(MAX_VALUE)}/2),

     * rounding to {@code double} will result in an infinity and if the

     * exact value of {@code s} is small enough in magnitude (less

     * than or equal to {@link #MIN_VALUE}/2), rounding to float will

     * result in a zero.

     *

     * Finally, after rounding a {@code Double} object representing

     * this {@code double} value is returned.

     *

     * <p> To interpret localized string representations of a

     * floating-point value, use subclasses of {@link

     * java.text.NumberFormat}.

     *

     * <p>Note that trailing format specifiers, specifiers that

     * determine the type of a floating-point literal

     * ({@code 1.0f} is a {@code float} value;

     * {@code 1.0d} is a {@code double} value), do

     * <em>not</em> influence the results of this method.  In other

     * words, the numerical value of the input string is converted

     * directly to the target floating-point type.  The two-step

     * sequence of conversions, string to {@code float} followed

     * by {@code float} to {@code double}, is <em>not</em>

     * equivalent to converting a string directly to

     * {@code double}. For example, the {@code float}

     * literal {@code 0.1f} is equal to the {@code double}

     * value {@code 0.10000000149011612}; the {@code float}

     * literal {@code 0.1f} represents a different numerical

     * value than the {@code double} literal

     * {@code 0.1}. (The numerical value 0.1 cannot be exactly

     * represented in a binary floating-point number.)

     *

     * <p>To avoid calling this method on an invalid string and having

     * a {@code NumberFormatException} be thrown, the regular

     * expression below can be used to screen the input string:

     *

     * <code>

     * <pre>

     *  final String Digits     = "(\\p{Digit}+)";

     *  final String HexDigits  = "(\\p{XDigit}+)";

     *  // an exponent is 'e' or 'E' followed by an optionally

     *  // signed decimal integer.

     *  final String Exp        = "[eE][+-]?"+Digits;

     *  final String fpRegex    =

     *      ("[\\x00-\\x20]*"+  // Optional leading "whitespace"

     *       "[+-]?(" + // Optional sign character

     *       "NaN|" +           // "NaN" string

     *       "Infinity|" +      // "Infinity" string

     *

     *       // A decimal floating-point string representing a finite positive

     *       // number without a leading sign has at most five basic pieces:

     *       // Digits . Digits ExponentPart FloatTypeSuffix

     *       //

     *       // Since this method allows integer-only strings as input

     *       // in addition to strings of floating-point literals, the

     *       // two sub-patterns below are simplifications of the grammar

     *       // productions from section 3.10.2 of

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

     *

     *       // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt

     *       "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+

     *

     *       // . Digits ExponentPart_opt FloatTypeSuffix_opt

     *       "(\\.("+Digits+")("+Exp+")?)|"+

     *

     *       // Hexadecimal strings

     *       "((" +

     *        // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt

     *        "(0[xX]" + HexDigits + "(\\.)?)|" +

     *

     *        // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt

     *        "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +

     *

     *        ")[pP][+-]?" + Digits + "))" +

     *       "[fFdD]?))" +

     *       "[\\x00-\\x20]*");// Optional trailing "whitespace"

     *

     *  if (Pattern.matches(fpRegex, myString))

     *      Double.valueOf(myString); // Will not throw NumberFormatException

     *  else {

     *      // Perform suitable alternative action

     *  }

     * </pre>

     * </code>

     *

     * @param      s   the string to be parsed.

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

     *             represented by the {@code String} argument.

     * @throws     NumberFormatException  if the string does not contain a

     *             parsable number.

     */

    @JavaScriptBody(args="s", body="return parseFloat(s);")

    public static Double valueOf(String s) throws NumberFormatException {

        throw new UnsupportedOperationException();

//        return new Double(FloatingDecimal.readJavaFormatString(s).doubleValue());

    }

    /**

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

     * {@code double} value.

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

     * should generally be used in preference to the constructor

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

     * significantly better space and time performance by caching

     * frequently requested values.

     *

     * @param  d a double value.

     * @return a {@code Double} instance representing {@code d}.

     * @since  1.5

     */

    public static Double valueOf(double d) {

        return new Double(d);

    }

    /**

     * Returns a new {@code double} initialized to the value

     * represented by the specified {@code String}, as performed

     * by the {@code valueOf} method of class

     * {@code Double}.

     *

     * @param  s   the string to be parsed.

     * @return the {@code double} value represented by the string

     *         argument.

     * @throws NullPointerException  if the string is null

     * @throws NumberFormatException if the string does not contain

     *         a parsable {@code double}.

     * @see    java.lang.Double#valueOf(String)

     * @since 1.2

     */

    @JavaScriptBody(args="s", body="return parseFloat(s);")

    public static double parseDouble(String s) throws NumberFormatException {

        throw new UnsupportedOperationException();

//        return FloatingDecimal.readJavaFormatString(s).doubleValue();

    }

    /**

     * Returns {@code true} if the specified number is a

     * Not-a-Number (NaN) value, {@code false} otherwise.

     *

     * @param   v   the value to be tested.

     * @return  {@code true} if the value of the argument is NaN;

     *          {@code false} otherwise.

     */

    static public boolean isNaN(double v) {

        return (v != v);

    }

    /**

     * Returns {@code true} if the specified number is infinitely

     * large in magnitude, {@code false} otherwise.

     *

     * @param   v   the value to be tested.

     * @return  {@code true} if the value of the argument is positive

     *          infinity or negative infinity; {@code false} otherwise.

     */

    static public boolean isInfinite(double v) {

        return (v == POSITIVE_INFINITY) || (v == NEGATIVE_INFINITY);

    }

    /**

     * The value of the Double.

     *

     * @serial

     */

    private final double value;

    /**

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

     * represents the primitive {@code double} argument.

     *

     * @param   value   the value to be represented by the {@code Double}.

     */

    public Double(double value) {

        this.value = value;

    }

    /**

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

     * represents the floating-point value of type {@code double}

     * represented by the string. The string is converted to a

     * {@code double} value as if by the {@code valueOf} method.

     *

     * @param  s  a string to be converted to a {@code Double}.

     * @throws    NumberFormatException  if the string does not contain a

     *            parsable number.

     * @see       java.lang.Double#valueOf(java.lang.String)

     */

    public Double(String s) throws NumberFormatException {

        // REMIND: this is inefficient

        this(valueOf(s).doubleValue());

    }

    /**

     * Returns {@code true} if this {@code Double} value is

     * a Not-a-Number (NaN), {@code false} otherwise.

     *

     * @return  {@code true} if the value represented by this object is

     *          NaN; {@code false} otherwise.

     */

    public boolean isNaN() {

        return isNaN(value);

    }

    /**

     * Returns {@code true} if this {@code Double} value is

     * infinitely large in magnitude, {@code false} otherwise.

     *

     * @return  {@code true} if the value represented by this object is

     *          positive infinity or negative infinity;

     *          {@code false} otherwise.

     */

    public boolean isInfinite() {

        return isInfinite(value);

    }

    /**

     * Returns a string representation of this {@code Double} object.

     * The primitive {@code double} value represented by this

     * object is converted to a string exactly as if by the method

     * {@code toString} of one argument.

     *

     * @return  a {@code String} representation of this object.

     * @see java.lang.Double#toString(double)

     */

    public String toString() {

        return toString(value);

    }

    /**

     * Returns the value of this {@code Double} as a {@code byte} (by

     * casting to a {@code byte}).

     *

     * @return  the {@code double} value represented by this object

     *          converted to type {@code byte}

     * @since JDK1.1

     */

    public byte byteValue() {

        return (byte)value;

    }

    /**

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

     * {@code short} (by casting to a {@code short}).

     *

     * @return  the {@code double} value represented by this object

     *          converted to type {@code short}

     * @since JDK1.1

     */

    public short shortValue() {

        return (short)value;

    }

    /**

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

     * {@code int} (by casting to type {@code int}).

     *

     * @return  the {@code double} value represented by this object

     *          converted to type {@code int}

     */

    public int intValue() {

        return (int)value;

    }

    /**

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

     * {@code long} (by casting to type {@code long}).

     *

     * @return  the {@code double} value represented by this object

     *          converted to type {@code long}

     */

    public long longValue() {

        return (long)value;

    }

    /**

     * Returns the {@code float} value of this

     * {@code Double} object.

     *

     * @return  the {@code double} value represented by this object

     *          converted to type {@code float}

     * @since JDK1.0

     */

    public float floatValue() {

        return (float)value;

    }

    /**

     * Returns the {@code double} value of this

     * {@code Double} object.

     *

     * @return the {@code double} value represented by this object

     */

    public double doubleValue() {

        return (double)value;

    }

    /**

     * Returns a hash code for this {@code Double} object. The

     * result is the exclusive OR of the two halves of the

     * {@code long} integer bit representation, exactly as

     * produced by the method {@link #doubleToLongBits(double)}, of

     * the primitive {@code double} value represented by this

     * {@code Double} object. That is, the hash code is the value

     * of the expression:

     *

     * <blockquote>

     *  {@code (int)(v^(v>>>32))}

     * </blockquote>

     *

     * where {@code v} is defined by:

     *

     * <blockquote>

     *  {@code long v = Double.doubleToLongBits(this.doubleValue());}

     * </blockquote>

     *

     * @return  a {@code hash code} value for this object.

     */

    public int hashCode() {

        long bits = doubleToLongBits(value);

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

    }

    /**

     * Compares this object against the specified object.  The result

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

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

     * represents a {@code double} that has the same value as the

     * {@code double} represented by this object. For this

     * purpose, two {@code double} values are considered to be

     * the same if and only if the method {@link

     * #doubleToLongBits(double)} returns the identical

     * {@code long} value when applied to each.

     *

     * <p>Note that in most cases, for two instances of class

     * {@code Double}, {@code d1} and {@code d2}, the

     * value of {@code d1.equals(d2)} is {@code true} if and

     * only if

     *

     * <blockquote>

     *  {@code d1.doubleValue() == d2.doubleValue()}

     * </blockquote>

     *

     * <p>also has the value {@code true}. However, there are two

     * exceptions:

     * <ul>

     * <li>If {@code d1} and {@code d2} both represent

     *     {@code Double.NaN}, then the {@code equals} method

     *     returns {@code true}, even though

     *     {@code Double.NaN==Double.NaN} has the value

     *     {@code false}.

     * <li>If {@code d1} represents {@code +0.0} while

     *     {@code d2} represents {@code -0.0}, or vice versa,

     *     the {@code equal} test has the value {@code false},

     *     even though {@code +0.0==-0.0} has the value {@code true}.

     * </ul>

     * This definition allows hash tables to operate properly.

     * @param   obj   the object to compare with.

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

     *          {@code false} otherwise.

     * @see java.lang.Double#doubleToLongBits(double)

     */

    public boolean equals(Object obj) {

        return (obj instanceof Double)

               && (((Double)obj).value) == value;

    }

    /**

     * Returns a representation of the specified floating-point value

     * according to the IEEE 754 floating-point "double

     * format" bit layout.

     *

     * <p>Bit 63 (the bit that is selected by the mask

     * {@code 0x8000000000000000L}) represents the sign of the

     * floating-point number. Bits

     * 62-52 (the bits that are selected by the mask

     * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0

     * (the bits that are selected by the mask

     * {@code 0x000fffffffffffffL}) represent the significand

     * (sometimes called the mantissa) of the floating-point number.

     *

     * <p>If the argument is positive infinity, the result is

     * {@code 0x7ff0000000000000L}.

     *

     * <p>If the argument is negative infinity, the result is

     * {@code 0xfff0000000000000L}.

     *

     * <p>If the argument is NaN, the result is

     * {@code 0x7ff8000000000000L}.

     *

     * <p>In all cases, the result is a {@code long} integer that, when

     * given to the {@link #longBitsToDouble(long)} method, will produce a

     * floating-point value the same as the argument to

     * {@code doubleToLongBits} (except all NaN values are

     * collapsed to a single "canonical" NaN value).

     *

     * @param   value   a {@code double} precision floating-point number.

     * @return the bits that represent the floating-point number.

     */

    public static long doubleToLongBits(double value) {

        throw new UnsupportedOperationException();

//        long result = doubleToRawLongBits(value);

//        // Check for NaN based on values of bit fields, maximum

//        // exponent and nonzero significand.

//        if ( ((result & DoubleConsts.EXP_BIT_MASK) ==

//              DoubleConsts.EXP_BIT_MASK) &&

//             (result & DoubleConsts.SIGNIF_BIT_MASK) != 0L)

//            result = 0x7ff8000000000000L;

//        return result;

    }

    /**

     * Returns a representation of the specified floating-point value

     * according to the IEEE 754 floating-point "double

     * format" bit layout, preserving Not-a-Number (NaN) values.

     *

     * <p>Bit 63 (the bit that is selected by the mask

     * {@code 0x8000000000000000L}) represents the sign of the

     * floating-point number. Bits

     * 62-52 (the bits that are selected by the mask

     * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0

     * (the bits that are selected by the mask

     * {@code 0x000fffffffffffffL}) represent the significand

     * (sometimes called the mantissa) of the floating-point number.

     *

     * <p>If the argument is positive infinity, the result is

     * {@code 0x7ff0000000000000L}.

     *

     * <p>If the argument is negative infinity, the result is

     * {@code 0xfff0000000000000L}.

     *

     * <p>If the argument is NaN, the result is the {@code long}

     * integer representing the actual NaN value.  Unlike the

     * {@code doubleToLongBits} method,

     * {@code doubleToRawLongBits} does not collapse all the bit

     * patterns encoding a NaN to a single "canonical" NaN

     * value.

     *

     * <p>In all cases, the result is a {@code long} integer that,

     * when given to the {@link #longBitsToDouble(long)} method, will

     * produce a floating-point value the same as the argument to

     * {@code doubleToRawLongBits}.

     *

     * @param   value   a {@code double} precision floating-point number.

     * @return the bits that represent the floating-point number.

     * @since 1.3

     */

    public static native long doubleToRawLongBits(double value);

    /**

     * Returns the {@code double} value corresponding to a given

     * bit representation.

     * The argument is considered to be a representation of a

     * floating-point value according to the IEEE 754 floating-point

     * "double format" bit layout.

     *

     * <p>If the argument is {@code 0x7ff0000000000000L}, the result

     * is positive infinity.

     *

     * <p>If the argument is {@code 0xfff0000000000000L}, the result

     * is negative infinity.

     *

     * <p>If the argument is any value in the range

     * {@code 0x7ff0000000000001L} through

     * {@code 0x7fffffffffffffffL} or in the range

     * {@code 0xfff0000000000001L} through

     * {@code 0xffffffffffffffffL}, the result is a NaN.  No IEEE

     * 754 floating-point operation provided by Java can distinguish

     * between two NaN values of the same type with different bit

     * patterns.  Distinct values of NaN are only distinguishable by

     * use of the {@code Double.doubleToRawLongBits} method.

     *

     * <p>In all other cases, let <i>s</i>, <i>e</i>, and <i>m</i> be three

     * values that can be computed from the argument:

     *

     * <blockquote><pre>

     * int s = ((bits >> 63) == 0) ? 1 : -1;

     * int e = (int)((bits >> 52) & 0x7ffL);

     * long m = (e == 0) ?

     *                 (bits & 0xfffffffffffffL) << 1 :

     *                 (bits & 0xfffffffffffffL) | 0x10000000000000L;

     * </pre></blockquote>

     *

     * Then the floating-point result equals the value of the mathematical

     * expression <i>s</i>&middot;<i>m</i>&middot;2<sup><i>e</i>-1075</sup>.

     *

     * <p>Note that this method may not be able to return a

     * {@code double} NaN with exactly same bit pattern as the

     * {@code long} argument.  IEEE 754 distinguishes between two

     * kinds of NaNs, quiet NaNs and <i>signaling NaNs</i>.  The

     * differences between the two kinds of NaN are generally not

     * visible in Java.  Arithmetic operations on signaling NaNs turn

     * them into quiet NaNs with a different, but often similar, bit

     * pattern.  However, on some processors merely copying a

     * signaling NaN also performs that conversion.  In particular,

     * copying a signaling NaN to return it to the calling method

     * may perform this conversion.  So {@code longBitsToDouble}

     * may not be able to return a {@code double} with a

     * signaling NaN bit pattern.  Consequently, for some

     * {@code long} values,

     * {@code doubleToRawLongBits(longBitsToDouble(start))} may

     * <i>not</i> equal {@code start}.  Moreover, which

     * particular bit patterns represent signaling NaNs is platform

     * dependent; although all NaN bit patterns, quiet or signaling,

     * must be in the NaN range identified above.

     *

     * @param   bits   any {@code long} integer.

     * @return  the {@code double} floating-point value with the same

     *          bit pattern.

     */

    public static native double longBitsToDouble(long bits);

    /**

     * Compares two {@code Double} objects numerically.  There

     * are two ways in which comparisons performed by this method

     * differ from those performed by the Java language numerical

     * comparison operators ({@code <, <=, ==, >=, >})

     * when applied to primitive {@code double} values:

     * <ul><li>

     *          {@code Double.NaN} is considered by this method

     *          to be equal to itself and greater than all other

     *          {@code double} values (including

     *          {@code Double.POSITIVE_INFINITY}).

     * <li>

     *          {@code 0.0d} is considered by this method to be greater

     *          than {@code -0.0d}.

     * </ul>

     * This ensures that the <i>natural ordering</i> of

     * {@code Double} objects imposed by this method is <i>consistent

     * with equals</i>.

     *

     * @param   anotherDouble   the {@code Double} to be compared.

     * @return  the value {@code 0} if {@code anotherDouble} is

     *          numerically equal to this {@code Double}; a value

     *          less than {@code 0} if this {@code Double}

     *          is numerically less than {@code anotherDouble};

     *          and a value greater than {@code 0} if this

     *          {@code Double} is numerically greater than

     *          {@code anotherDouble}.

     *

     * @since   1.2

     */

    public int compareTo(Double anotherDouble) {

        return Double.compare(value, anotherDouble.value);

    }

    /**

     * Compares the two specified {@code double} values. The sign

     * of the integer value returned is the same as that of the

     * integer that would be returned by the call:

     * <pre>

     *    new Double(d1).compareTo(new Double(d2))

     * </pre>

     *

     * @param   d1        the first {@code double} to compare

     * @param   d2        the second {@code double} to compare

     * @return  the value {@code 0} if {@code d1} is

     *          numerically equal to {@code d2}; a value less than

     *          {@code 0} if {@code d1} is numerically less than

     *          {@code d2}; and a value greater than {@code 0}

     *          if {@code d1} is numerically greater than

     *          {@code d2}.

     * @since 1.4

     */

    public static int compare(double d1, double d2) {

        if (d1 < d2)

            return -1;           // Neither val is NaN, thisVal is smaller

        if (d1 > d2)

            return 1;            // Neither val is NaN, thisVal is larger

        // Cannot use doubleToRawLongBits because of possibility of NaNs.

        long thisBits    = Double.doubleToLongBits(d1);

        long anotherBits = Double.doubleToLongBits(d2);

        return (thisBits == anotherBits ?  0 : // Values are equal

                (thisBits < anotherBits ? -1 : // (-0.0, 0.0) or (!NaN, NaN)

                 1));                          // (0.0, -0.0) or (NaN, !NaN)

    }

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

    private static final long serialVersionUID = -9172774392245257468L;