mcs/class/corlib/System/Double.cs

   1 //
   2 // System.Double.cs
   3 //
   4 // Author:
   5 //   Miguel de Icaza (miguel@ximian.com)
   6 //   Bob Smith       (bob@thestuff.net)
   7 //
   8 // (C) Ximian, Inc.  http://www.ximian.com
   9 // (C) Bob Smith.    http://www.thestuff.net
  10 //
  11
  12 //
  13 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  14 //
  15 // Permission is hereby granted, free of charge, to any person obtaining
  16 // a copy of this software and associated documentation files (the
  17 // "Software"), to deal in the Software without restriction, including
  18 // without limitation the rights to use, copy, modify, merge, publish,
  19 // distribute, sublicense, and/or sell copies of the Software, and to
  20 // permit persons to whom the Software is furnished to do so, subject to
  21 // the following conditions:
  22 //
  23 // The above copyright notice and this permission notice shall be
  24 // included in all copies or substantial portions of the Software.
  25 //
  26 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  27 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  28 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  29 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  30 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  31 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  32 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  33 //
  34
  35 using System.Globalization;
  36 using System.Runtime.CompilerServices;
  37
  38 #if NET_2_0
  39 using System.Runtime.ConstrainedExecution;
  40 #endif
  41
  42 namespace System {
  43
  44         [Serializable]
  45         public struct Double : IComparable, IFormattable, IConvertible
  46 #if NET_2_0
  47                 , IComparable <double>, IEquatable <double>
  48 #endif
  49         {
  50                 public const double Epsilon = 4.9406564584124650e-324;
  51                 public const double MaxValue =  1.7976931348623157e308;
  52                 public const double MinValue = -1.7976931348623157e308;
  53                 public const double NaN = 0.0d / 0.0d;
  54                 public const double NegativeInfinity = -1.0d / 0.0d;
  55                 public const double PositiveInfinity = 1.0d / 0.0d;
  56
  57                 internal double m_value;
  58
  59                 public int CompareTo (object v)
  60                 {
  61                         if (v == null)
  62                                 return 1;
  63
  64                         if (!(v is System.Double))
  65                                 throw new ArgumentException (Locale.GetText ("Value is not a System.Double"));
  66
  67                         double dv = (double)v;
  68
  69                         if (IsPositiveInfinity(m_value) && IsPositiveInfinity(dv))
  70                                 return 0;
  71
  72                         if (IsNegativeInfinity(m_value) && IsNegativeInfinity(dv))
  73                                 return 0;
  74
  75                         if (IsNaN(dv))
  76                                 if (IsNaN(m_value))
  77                                         return 0;
  78                                 else
  79                                         return 1;
  80
  81                         if (IsNaN(m_value))
  82                                 if (IsNaN(dv))
  83                                         return 0;
  84                                 else
  85                                         return -1;
  86
  87                         if (m_value > dv) return 1;
  88                         else if (m_value < dv) return -1;
  89                         else return 0;
  90                 }
  91
  92                 public override bool Equals (object o)
  93                 {
  94                         if (!(o is System.Double))
  95                                 return false;
  96
  97                         if (IsNaN ((double)o)) {
  98                                 if (IsNaN(m_value))
  99                                         return true;
 100                                 else
 101                                         return false;
 102                         }
 103
 104                         return ((double) o) == m_value;
 105                 }
 106
 107 #if NET_2_0
 108                 public int CompareTo (double value)
 109                 {
 110                         if (IsPositiveInfinity(m_value) && IsPositiveInfinity(value))
 111                                 return 0;
 112
 113                         if (IsNegativeInfinity(m_value) && IsNegativeInfinity(value))
 114                                 return 0;
 115
 116                         if (IsNaN(value))
 117                                 if (IsNaN(m_value))
 118                                         return 0;
 119                                 else
 120                                         return 1;
 121
 122                         if (IsNaN(m_value))
 123                                 if (IsNaN(value))
 124                                         return 0;
 125                                 else
 126                                         return -1;
 127
 128                         if (m_value > value) return 1;
 129                         else if (m_value < value) return -1;
 130                         else return 0;
 131                 }
 132
 133                 public bool Equals (double value)
 134                 {
 135                         if (IsNaN (value)) {
 136                                 if (IsNaN(m_value))
 137                                         return true;
 138                                 else
 139                                         return false;
 140                         }
 141
 142                         return value == m_value;
 143                 }
 144 #endif
 145
 146                 public override unsafe int GetHashCode ()
 147                 {
 148                         double d = m_value;
 149                         return (*((long*)&d)).GetHashCode ();
 150                 }
 151
 152                 public static bool IsInfinity (double d)
 153                 {
 154                         return (d == PositiveInfinity || d == NegativeInfinity);
 155                 }
 156
 157 #if NET_2_0
 158                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 159 #endif
 160                 public static bool IsNaN (double d)
 161                 {
 162 #pragma warning disable 1718
 163                         return (d != d);
 164 #pragma warning restore
 165                 }
 166
 167                 public static bool IsNegativeInfinity (double d)
 168                 {
 169                         return (d < 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
 170                 }
 171
 172                 public static bool IsPositiveInfinity (double d)
 173                 {
 174                         return (d > 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
 175                 }
 176
 177                 public static double Parse (string s)
 178                 {
 179                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), null);
 180                 }
 181
 182                 public static double Parse (string s, IFormatProvider fp)
 183                 {
 184                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), fp);
 185                 }
 186
 187                 public static double Parse (string s, NumberStyles style)
 188                 {
 189                         return Parse (s, style, null);
 190                 }
 191
 192                 // We're intentionally using constants here to avoid some bigger headaches in mcs.
 193                 // This struct must be compiled before System.Enum so we can't use enums here.
 194                 private const int State_AllowSign = 1;
 195                 private const int State_Digits = 2;
 196                 private const int State_Decimal = 3;
 197                 private const int State_ExponentSign = 4;
 198                 private const int State_Exponent = 5;
 199                 private const int State_ConsumeWhiteSpace = 6;
 200
 201                 public static double Parse (string s, NumberStyles style, IFormatProvider provider)
 202                 {
 203                         Exception exc;
 204                         double result;
 205
 206                         if (!Parse (s, style, provider, false, out result, out exc))
 207                                 throw exc;
 208
 209                         return result;
 210                 }
 211
 212                 [MonoTODO("check if digits are group in correct numbers between the group separators")]
 213                 internal static bool Parse (string s, NumberStyles style, IFormatProvider provider, bool tryParse, out double result, out Exception exc)
 214                 {
 215                         result = 0;
 216                         exc = null;
 217
 218                         if (s == null) {
 219                                 if (!tryParse)
 220                                         exc = new ArgumentNullException ("s");
 221                                 return false;
 222                         }
 223 #if NET_2_0
 224                         // yes it's counter intuitive (buggy?) but even TryParse actually throws in this case
 225                         if ((style & NumberStyles.AllowHexSpecifier) != 0) {
 226                                 string msg = Locale.GetText ("Double doesn't support parsing with '{0}'.", "AllowHexSpecifier");
 227                                 throw new ArgumentException (msg);
 228                         }
 229 #endif
 230                         if (style > NumberStyles.Any) {
 231                                 if (!tryParse)
 232                                         exc = new ArgumentException();
 233                                 return false;
 234                         }
 235
 236                         NumberFormatInfo format = NumberFormatInfo.GetInstance(provider);
 237                         if (format == null) throw new Exception("How did this happen?");
 238
 239                         if (s == format.NaNSymbol) {
 240                                 result = Double.NaN;
 241                                 return true;
 242                         }
 243                         if (s == format.PositiveInfinitySymbol) {
 244                                 result = Double.PositiveInfinity;
 245                                 return true;
 246                         }
 247                         if (s == format.NegativeInfinitySymbol) {
 248                                 result = Double.NegativeInfinity;
 249                                 return true;
 250                         }
 251
 252                         //
 253                         // validate and prepare string for C
 254                         //
 255                         int len = s.Length;
 256                         byte [] b = new byte [len + 1];
 257                         int didx = 0;
 258                         int sidx = 0;
 259                         char c;
 260
 261                         if ((style & NumberStyles.AllowLeadingWhite) != 0){
 262                                 while (sidx < len && Char.IsWhiteSpace (c = s [sidx]))
 263                                        sidx++;
 264
 265                                 if (sidx == len) {
 266                                         if (!tryParse)
 267                                                 exc = Int32.GetFormatException ();
 268                                         return true;
 269                                 }
 270                         }
 271
 272                         bool allow_trailing_white = ((style & NumberStyles.AllowTrailingWhite) != 0);
 273
 274                         //
 275                         // Machine state
 276                         //
 277                         int state = State_AllowSign;
 278
 279                         //
 280                         // Setup
 281                         //
 282                         string decimal_separator = null;
 283                         string group_separator = null;
 284                         int decimal_separator_len = 0;
 285                         int group_separator_len = 0;
 286                         if ((style & NumberStyles.AllowDecimalPoint) != 0){
 287                                 decimal_separator = format.NumberDecimalSeparator;
 288                                 decimal_separator_len = decimal_separator.Length;
 289                         }
 290                         if ((style & NumberStyles.AllowThousands) != 0){
 291                                 group_separator = format.NumberGroupSeparator;
 292                                 group_separator_len = group_separator.Length;
 293                         }
 294                         string positive = format.PositiveSign;
 295                         string negative = format.NegativeSign;
 296
 297                         for (; sidx < len; sidx++){
 298                                 c = s [sidx];
 299
 300                                 if (c == '\0') {
 301                                         sidx = len;
 302                                         continue;
 303                                 }
 304                                 switch (state){
 305                                 case State_AllowSign:
 306                                         if ((style & NumberStyles.AllowLeadingSign) != 0){
 307                                                 if (c == positive [0] &&
 308                                                     s.Substring (sidx, positive.Length) == positive){
 309                                                         state = State_Digits;
 310                                                         sidx += positive.Length-1;
 311                                                         continue;
 312                                                 }
 313
 314                                                 if (c == negative [0] &&
 315                                                     s.Substring (sidx, negative.Length) == negative){
 316                                                         state = State_Digits;
 317                                                         b [didx++] = (byte) '-';
 318                                                         sidx += negative.Length-1;
 319                                                         continue;
 320                                                 }
 321                                         }
 322                                         state = State_Digits;
 323                                         goto case State_Digits;
 324
 325                                 case State_Digits:
 326                                         if (Char.IsDigit (c)){
 327                                                 b [didx++] = (byte) c;
 328                                                 break;
 329                                         }
 330                                         if (c == 'e' || c == 'E')
 331                                                 goto case State_Decimal;
 332
 333                                         if (decimal_separator != null &&
 334                                             decimal_separator [0] == c){
 335                                                 if (s.Substring (sidx, decimal_separator_len) ==
 336                                                     decimal_separator){
 337                                                         b [didx++] = (byte) '.';
 338                                                         sidx += decimal_separator_len-1;
 339                                                         state = State_Decimal;
 340                                                         break;
 341                                                 }
 342                                         }
 343                                         if (group_separator != null &&
 344                                             group_separator [0] == c){
 345                                                 if (s.Substring (sidx, group_separator_len) ==
 346                                                     group_separator){
 347                                                         sidx += group_separator_len-1;
 348                                                         state = State_Digits;
 349                                                         break;
 350                                                 }
 351                                         }
 352
 353                                         if (Char.IsWhiteSpace (c))
 354                                                 goto case State_ConsumeWhiteSpace;
 355
 356                                         if (!tryParse)
 357                                                 exc = new FormatException ("Unknown char: " + c);
 358                                         return false;
 359
 360                                 case State_Decimal:
 361                                         if (Char.IsDigit (c)){
 362                                                 b [didx++] = (byte) c;
 363                                                 break;
 364                                         }
 365
 366                                         if (c == 'e' || c == 'E'){
 367                                                 if ((style & NumberStyles.AllowExponent) == 0)
 368                                                         throw new FormatException ("Unknown char: " + c);
 369                                                 b [didx++] = (byte) c;
 370                                                 state = State_ExponentSign;
 371                                                 break;
 372                                         }
 373
 374                                         if (Char.IsWhiteSpace (c))
 375                                                 goto case State_ConsumeWhiteSpace;
 376
 377                                         if (!tryParse)
 378                                                 exc = new FormatException ("Unknown char: " + c);
 379                                         return false;
 380
 381                                 case State_ExponentSign:
 382                                         if (Char.IsDigit (c)){
 383                                                 state = State_Exponent;
 384                                                 goto case State_Exponent;
 385                                         }
 386
 387                                         if (c == positive [0] &&
 388                                             s.Substring (sidx, positive.Length) == positive){
 389                                                 state = State_Digits;
 390                                                 sidx += positive.Length-1;
 391                                                 continue;
 392                                         }
 393
 394                                         if (c == negative [0] &&
 395                                             s.Substring (sidx, negative.Length) == negative){
 396                                                 state = State_Digits;
 397                                                 b [didx++] = (byte) '-';
 398                                                 sidx += negative.Length-1;
 399                                                 continue;
 400                                         }
 401
 402                                         if (Char.IsWhiteSpace (c))
 403                                                 goto case State_ConsumeWhiteSpace;
 404
 405                                         if (!tryParse)
 406                                                 exc = new FormatException ("Unknown char: " + c);
 407                                         return false;
 408
 409                                 case State_Exponent:
 410                                         if (Char.IsDigit (c)){
 411                                                 b [didx++] = (byte) c;
 412                                                 break;
 413                                         }
 414
 415                                         if (Char.IsWhiteSpace (c))
 416                                                 goto case State_ConsumeWhiteSpace;
 417
 418                                         if (!tryParse)
 419                                                 exc = new FormatException ("Unknown char: " + c);
 420                                         return false;
 421
 422                                 case State_ConsumeWhiteSpace:
 423                                         if (allow_trailing_white && Char.IsWhiteSpace (c))
 424                                                 break;
 425
 426                                         if (!tryParse)
 427                                                 exc = new FormatException ("Unknown char");
 428                                         return false;
 429                                 }
 430                         }
 431
 432                         b [didx] = 0;
 433                         unsafe {
 434                                 fixed (byte *p = &b [0]){
 435                                         double retVal;
 436                                         if (!ParseImpl (p, out retVal)) {
 437                                                 if (!tryParse)
 438                                                         exc = Int32.GetFormatException ();
 439                                                 return false;
 440                                         }
 441                                         if (IsPositiveInfinity(retVal) || IsNegativeInfinity(retVal)) {
 442                                                 if (!tryParse)
 443                                                         exc = new OverflowException ();
 444                                                 return false;
 445                                         }
 446
 447                                         result = retVal;
 448                                         return true;
 449                                 }
 450                         }
 451                 }
 452
 453                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 454                 unsafe private static extern bool ParseImpl (byte *byte_ptr, out double value);
 455
 456                 public static bool TryParse (string s,
 457                                              NumberStyles style,
 458                                              IFormatProvider provider,
 459                                              out double result)
 460                 {
 461                         Exception exc;
 462                         if (!Parse (s, style, provider, true, out result, out exc)) {
 463                                 result = 0;
 464                                 return false;
 465                         }
 466
 467                         return true;
 468                 }
 469 #if NET_2_0
 470                 public static bool TryParse (string s, out double result)
 471                 {
 472                         return TryParse (s, NumberStyles.Any, null, out result);
 473                 }
 474 #endif
 475                 public override string ToString ()
 476                 {
 477                         return ToString (null, null);
 478                 }
 479
 480                 public string ToString (IFormatProvider fp)
 481                 {
 482                         return ToString (null, fp);
 483                 }
 484
 485                 public string ToString (string format)
 486                 {
 487                         return ToString (format, null);
 488                 }
 489
 490                 public string ToString (string format, IFormatProvider fp)
 491                 {
 492                         NumberFormatInfo nfi = NumberFormatInfo.GetInstance (fp);
 493                         return NumberFormatter.NumberToString (format, m_value, nfi);
 494                 }
 495
 496                 // =========== IConvertible Methods =========== //
 497
 498                 public TypeCode GetTypeCode ()
 499                 {
 500                         return TypeCode.Double;
 501                 }
 502
 503                 object IConvertible.ToType (Type conversionType, IFormatProvider provider)
 504                 {
 505                         return System.Convert.ToType(m_value, conversionType, provider);
 506                 }
 507
 508                 bool IConvertible.ToBoolean (IFormatProvider provider)
 509                 {
 510                         return System.Convert.ToBoolean(m_value);
 511                 }
 512
 513                 byte IConvertible.ToByte (IFormatProvider provider)
 514                 {
 515                         return System.Convert.ToByte(m_value);
 516                 }
 517
 518                 char IConvertible.ToChar (IFormatProvider provider)
 519                 {
 520                         throw new InvalidCastException();
 521                 }
 522
 523                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 524                 {
 525                         throw new InvalidCastException();
 526                 }
 527
 528                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 529                 {
 530                         return System.Convert.ToDecimal(m_value);
 531                 }
 532
 533                 double IConvertible.ToDouble (IFormatProvider provider)
 534                 {
 535                         return System.Convert.ToDouble(m_value);
 536                 }
 537
 538                 short IConvertible.ToInt16 (IFormatProvider provider)
 539                 {
 540                         return System.Convert.ToInt16(m_value);
 541                 }
 542
 543                 int IConvertible.ToInt32 (IFormatProvider provider)
 544                 {
 545                         return System.Convert.ToInt32(m_value);
 546                 }
 547
 548                 long IConvertible.ToInt64 (IFormatProvider provider)
 549                 {
 550                         return System.Convert.ToInt64(m_value);
 551                 }
 552
 553                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 554                 {
 555                         return System.Convert.ToSByte(m_value);
 556                 }
 557
 558                 float IConvertible.ToSingle (IFormatProvider provider)
 559                 {
 560                         return System.Convert.ToSingle(m_value);
 561                 }
 562
 563 /*
 564                 string IConvertible.ToString (IFormatProvider provider)
 565                 {
 566                         return ToString(provider);
 567                 }
 568 */
 569
 570                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 571                 {
 572                         return System.Convert.ToUInt16(m_value);
 573                 }
 574
 575                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 576                 {
 577                         return System.Convert.ToUInt32(m_value);
 578                 }
 579
 580                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 581                 {
 582                         return System.Convert.ToUInt64(m_value);
 583                 }
 584         }
 585 }