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                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  60                 extern internal static void AssertEndianity (out double value);
  61
  62                 public int CompareTo (object v)
  63                 {
  64                         if (v == null)
  65                                 return 1;
  66
  67                         if (!(v is System.Double))
  68                                 throw new ArgumentException (Locale.GetText ("Value is not a System.Double"));
  69
  70                         double dv = (double)v;
  71
  72                         if (IsPositiveInfinity(m_value) && IsPositiveInfinity(dv))
  73                                 return 0;
  74
  75                         if (IsNegativeInfinity(m_value) && IsNegativeInfinity(dv))
  76                                 return 0;
  77
  78                         if (IsNaN(dv))
  79                                 if (IsNaN(m_value))
  80                                         return 0;
  81                                 else
  82                                         return 1;
  83
  84                         if (IsNaN(m_value))
  85                                 if (IsNaN(dv))
  86                                         return 0;
  87                                 else
  88                                         return -1;
  89
  90                         if (m_value > dv) return 1;
  91                         else if (m_value < dv) return -1;
  92                         else return 0;
  93                 }
  94
  95                 public override bool Equals (object o)
  96                 {
  97                         if (!(o is System.Double))
  98                                 return false;
  99
 100                         if (IsNaN ((double)o)) {
 101                                 if (IsNaN(m_value))
 102                                         return true;
 103                                 else
 104                                         return false;
 105                         }
 106
 107                         return ((double) o) == m_value;
 108                 }
 109
 110 #if NET_2_0
 111                 public int CompareTo (double value)
 112                 {
 113                         if (IsPositiveInfinity(m_value) && IsPositiveInfinity(value))
 114                                 return 0;
 115
 116                         if (IsNegativeInfinity(m_value) && IsNegativeInfinity(value))
 117                                 return 0;
 118
 119                         if (IsNaN(value))
 120                                 if (IsNaN(m_value))
 121                                         return 0;
 122                                 else
 123                                         return 1;
 124
 125                         if (IsNaN(m_value))
 126                                 if (IsNaN(value))
 127                                         return 0;
 128                                 else
 129                                         return -1;
 130
 131                         if (m_value > value) return 1;
 132                         else if (m_value < value) return -1;
 133                         else return 0;
 134                 }
 135
 136                 public bool Equals (double value)
 137                 {
 138                         if (IsNaN (value)) {
 139                                 if (IsNaN(m_value))
 140                                         return true;
 141                                 else
 142                                         return false;
 143                         }
 144
 145                         return value == m_value;
 146                 }
 147 #endif
 148
 149                 public override unsafe int GetHashCode ()
 150                 {
 151                         double d = m_value;
 152                         return (*((long*)&d)).GetHashCode ();
 153                 }
 154
 155                 public static bool IsInfinity (double d)
 156                 {
 157                         return (d == PositiveInfinity || d == NegativeInfinity);
 158                 }
 159
 160 #if NET_2_0
 161                 [ReliabilityContractAttribute (Consistency.WillNotCorruptState, Cer.Success)]
 162 #endif
 163                 public static bool IsNaN (double d)
 164                 {
 165                         return (d != d);
 166                 }
 167
 168                 public static bool IsNegativeInfinity (double d)
 169                 {
 170                         return (d < 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
 171                 }
 172
 173                 public static bool IsPositiveInfinity (double d)
 174                 {
 175                         return (d > 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
 176                 }
 177
 178                 public static double Parse (string s)
 179                 {
 180                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), null);
 181                 }
 182
 183                 public static double Parse (string s, IFormatProvider fp)
 184                 {
 185                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), fp);
 186                 }
 187
 188                 public static double Parse (string s, NumberStyles style)
 189                 {
 190                         return Parse (s, style, null);
 191                 }
 192
 193                 // We're intentionally using constants here to avoid some bigger headaches in mcs.
 194                 // This struct must be compiled before System.Enum so we can't use enums here.
 195                 private const int State_AllowSign = 1;
 196                 private const int State_Digits = 2;
 197                 private const int State_Decimal = 3;
 198                 private const int State_ExponentSign = 4;
 199                 private const int State_Exponent = 5;
 200                 private const int State_ConsumeWhiteSpace = 6;
 201
 202                 public static double Parse (string s, NumberStyles style, IFormatProvider provider)
 203                 {
 204                         Exception exc;
 205                         double result;
 206
 207                         if (!Parse (s, style, provider, false, out result, out exc))
 208                                 throw exc;
 209
 210                         return result;
 211                 }
 212
 213                 [MonoTODO("check if digits are group in correct numbers between the group separators")]
 214                 internal static bool Parse (string s, NumberStyles style, IFormatProvider provider, bool tryParse, out double result, out Exception exc)
 215                 {
 216                         result = 0;
 217                         exc = null;
 218
 219                         if (s == null) {
 220                                 if (!tryParse)
 221                                         exc = new ArgumentNullException ("s");
 222                                 return false;
 223                         }
 224
 225                         if (style > NumberStyles.Any) {
 226                                 if (!tryParse)
 227                                         exc = new ArgumentException();
 228                                 return false;
 229                         }
 230
 231                         NumberFormatInfo format = NumberFormatInfo.GetInstance(provider);
 232                         if (format == null) throw new Exception("How did this happen?");
 233
 234                         if (s == format.NaNSymbol) {
 235                                 result = Double.NaN;
 236                                 return true;
 237                         }
 238                         if (s == format.PositiveInfinitySymbol) {
 239                                 result = Double.PositiveInfinity;
 240                                 return true;
 241                         }
 242                         if (s == format.NegativeInfinitySymbol) {
 243                                 result = Double.NegativeInfinity;
 244                                 return true;
 245                         }
 246
 247                         //
 248                         // validate and prepare string for C
 249                         //
 250                         int len = s.Length;
 251                         byte [] b = new byte [len + 1];
 252                         int didx = 0;
 253                         int sidx = 0;
 254                         char c;
 255
 256                         if ((style & NumberStyles.AllowLeadingWhite) != 0){
 257                                 while (sidx < len && Char.IsWhiteSpace (c = s [sidx]))
 258                                        sidx++;
 259
 260                                 if (sidx == len) {
 261                                         if (!tryParse)
 262                                                 exc = Int32.GetFormatException ();
 263                                         return true;
 264                                 }
 265                         }
 266
 267                         bool allow_trailing_white = ((style & NumberStyles.AllowTrailingWhite) != 0);
 268
 269                         //
 270                         // Machine state
 271                         //
 272                         int state = State_AllowSign;
 273
 274                         //
 275                         // Setup
 276                         //
 277                         string decimal_separator = null;
 278                         string group_separator = null;
 279                         int decimal_separator_len = 0;
 280                         int group_separator_len = 0;
 281                         if ((style & NumberStyles.AllowDecimalPoint) != 0){
 282                                 decimal_separator = format.NumberDecimalSeparator;
 283                                 decimal_separator_len = decimal_separator.Length;
 284                         }
 285                         if ((style & NumberStyles.AllowThousands) != 0){
 286                                 group_separator = format.NumberGroupSeparator;
 287                                 group_separator_len = group_separator.Length;
 288                         }
 289                         string positive = format.PositiveSign;
 290                         string negative = format.NegativeSign;
 291
 292                         for (; sidx < len; sidx++){
 293                                 c = s [sidx];
 294
 295                                 if (c == '\0') {
 296                                         sidx = len;
 297                                         continue;
 298                                 }
 299                                 switch (state){
 300                                 case State_AllowSign:
 301                                         if ((style & NumberStyles.AllowLeadingSign) != 0){
 302                                                 if (c == positive [0] &&
 303                                                     s.Substring (sidx, positive.Length) == positive){
 304                                                         state = State_Digits;
 305                                                         sidx += positive.Length-1;
 306                                                         continue;
 307                                                 }
 308
 309                                                 if (c == negative [0] &&
 310                                                     s.Substring (sidx, negative.Length) == negative){
 311                                                         state = State_Digits;
 312                                                         b [didx++] = (byte) '-';
 313                                                         sidx += negative.Length-1;
 314                                                         continue;
 315                                                 }
 316                                         }
 317                                         state = State_Digits;
 318                                         goto case State_Digits;
 319
 320                                 case State_Digits:
 321                                         if (Char.IsDigit (c)){
 322                                                 b [didx++] = (byte) c;
 323                                                 break;
 324                                         }
 325                                         if (c == 'e' || c == 'E')
 326                                                 goto case State_Decimal;
 327
 328                                         if (decimal_separator != null &&
 329                                             decimal_separator [0] == c){
 330                                                 if (s.Substring (sidx, decimal_separator_len) ==
 331                                                     decimal_separator){
 332                                                         b [didx++] = (byte) '.';
 333                                                         sidx += decimal_separator_len-1;
 334                                                         state = State_Decimal;
 335                                                         break;
 336                                                 }
 337                                         }
 338                                         if (group_separator != null &&
 339                                             group_separator [0] == c){
 340                                                 if (s.Substring (sidx, group_separator_len) ==
 341                                                     group_separator){
 342                                                         sidx += group_separator_len-1;
 343                                                         state = State_Digits;
 344                                                         break;
 345                                                 }
 346                                         }
 347
 348                                         if (Char.IsWhiteSpace (c))
 349                                                 goto case State_ConsumeWhiteSpace;
 350
 351                                         if (!tryParse)
 352                                                 exc = new FormatException ("Unknown char: " + c);
 353                                         return false;
 354
 355                                 case State_Decimal:
 356                                         if (Char.IsDigit (c)){
 357                                                 b [didx++] = (byte) c;
 358                                                 break;
 359                                         }
 360
 361                                         if (c == 'e' || c == 'E'){
 362                                                 if ((style & NumberStyles.AllowExponent) == 0)
 363                                                         throw new FormatException ("Unknown char: " + c);
 364                                                 b [didx++] = (byte) c;
 365                                                 state = State_ExponentSign;
 366                                                 break;
 367                                         }
 368
 369                                         if (Char.IsWhiteSpace (c))
 370                                                 goto case State_ConsumeWhiteSpace;
 371
 372                                         if (!tryParse)
 373                                                 exc = new FormatException ("Unknown char: " + c);
 374                                         return false;
 375
 376                                 case State_ExponentSign:
 377                                         if (Char.IsDigit (c)){
 378                                                 state = State_Exponent;
 379                                                 goto case State_Exponent;
 380                                         }
 381
 382                                         if (c == positive [0] &&
 383                                             s.Substring (sidx, positive.Length) == positive){
 384                                                 state = State_Digits;
 385                                                 sidx += positive.Length-1;
 386                                                 continue;
 387                                         }
 388
 389                                         if (c == negative [0] &&
 390                                             s.Substring (sidx, negative.Length) == negative){
 391                                                 state = State_Digits;
 392                                                 b [didx++] = (byte) '-';
 393                                                 sidx += negative.Length-1;
 394                                                 continue;
 395                                         }
 396
 397                                         if (Char.IsWhiteSpace (c))
 398                                                 goto case State_ConsumeWhiteSpace;
 399
 400                                         if (!tryParse)
 401                                                 exc = new FormatException ("Unknown char: " + c);
 402                                         return false;
 403
 404                                 case State_Exponent:
 405                                         if (Char.IsDigit (c)){
 406                                                 b [didx++] = (byte) c;
 407                                                 break;
 408                                         }
 409
 410                                         if (Char.IsWhiteSpace (c))
 411                                                 goto case State_ConsumeWhiteSpace;
 412
 413                                         if (!tryParse)
 414                                                 exc = new FormatException ("Unknown char: " + c);
 415                                         return false;
 416
 417                                 case State_ConsumeWhiteSpace:
 418                                         if (allow_trailing_white && Char.IsWhiteSpace (c))
 419                                                 break;
 420
 421                                         if (!tryParse)
 422                                                 exc = new FormatException ("Unknown char");
 423                                         return false;
 424                                 }
 425                         }
 426
 427                         b [didx] = 0;
 428                         unsafe {
 429                                 fixed (byte *p = &b [0]){
 430                                         double retVal;
 431                                         if (!ParseImpl (p, out retVal)) {
 432                                                 if (!tryParse)
 433                                                         exc = Int32.GetFormatException ();
 434                                                 return false;
 435                                         }
 436                                         if (IsPositiveInfinity(retVal) || IsNegativeInfinity(retVal)) {
 437                                                 if (!tryParse)
 438                                                         exc = new OverflowException ();
 439                                                 return false;
 440                                         }
 441
 442                                         result = retVal;
 443                                         return true;
 444                                 }
 445                         }
 446                 }
 447
 448                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 449                 unsafe private static extern bool ParseImpl (byte *byte_ptr, out double value);
 450
 451                 public static bool TryParse (string s,
 452                                              NumberStyles style,
 453                                              IFormatProvider provider,
 454                                              out double result)
 455                 {
 456                         Exception exc;
 457                         if (!Parse (s, style, provider, true, out result, out exc)) {
 458                                 result = 0;
 459                                 return false;
 460                         }
 461
 462                         return true;
 463                 }
 464
 465                 public override string ToString ()
 466                 {
 467                         return ToString (null, null);
 468                 }
 469
 470                 public string ToString (IFormatProvider fp)
 471                 {
 472                         return ToString (null, fp);
 473                 }
 474
 475                 public string ToString (string format)
 476                 {
 477                         return ToString (format, null);
 478                 }
 479
 480                 public string ToString (string format, IFormatProvider fp)
 481                 {
 482                         NumberFormatInfo nfi = NumberFormatInfo.GetInstance (fp);
 483                         return NumberFormatter.NumberToString (format, m_value, nfi);
 484                 }
 485
 486                 // =========== IConvertible Methods =========== //
 487
 488                 public TypeCode GetTypeCode ()
 489                 {
 490                         return TypeCode.Double;
 491                 }
 492
 493                 object IConvertible.ToType (Type conversionType, IFormatProvider provider)
 494                 {
 495                         return System.Convert.ToType(m_value, conversionType, provider);
 496                 }
 497
 498                 bool IConvertible.ToBoolean (IFormatProvider provider)
 499                 {
 500                         return System.Convert.ToBoolean(m_value);
 501                 }
 502
 503                 byte IConvertible.ToByte (IFormatProvider provider)
 504                 {
 505                         return System.Convert.ToByte(m_value);
 506                 }
 507
 508                 char IConvertible.ToChar (IFormatProvider provider)
 509                 {
 510                         throw new InvalidCastException();
 511                 }
 512
 513                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 514                 {
 515                         throw new InvalidCastException();
 516                 }
 517
 518                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 519                 {
 520                         return System.Convert.ToDecimal(m_value);
 521                 }
 522
 523                 double IConvertible.ToDouble (IFormatProvider provider)
 524                 {
 525                         return System.Convert.ToDouble(m_value);
 526                 }
 527
 528                 short IConvertible.ToInt16 (IFormatProvider provider)
 529                 {
 530                         return System.Convert.ToInt16(m_value);
 531                 }
 532
 533                 int IConvertible.ToInt32 (IFormatProvider provider)
 534                 {
 535                         return System.Convert.ToInt32(m_value);
 536                 }
 537
 538                 long IConvertible.ToInt64 (IFormatProvider provider)
 539                 {
 540                         return System.Convert.ToInt64(m_value);
 541                 }
 542
 543                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 544                 {
 545                         return System.Convert.ToSByte(m_value);
 546                 }
 547
 548                 float IConvertible.ToSingle (IFormatProvider provider)
 549                 {
 550                         return System.Convert.ToSingle(m_value);
 551                 }
 552
 553 /*
 554                 string IConvertible.ToString (IFormatProvider provider)
 555                 {
 556                         return ToString(provider);
 557                 }
 558 */
 559
 560                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 561                 {
 562                         return System.Convert.ToUInt16(m_value);
 563                 }
 564
 565                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 566                 {
 567                         return System.Convert.ToUInt32(m_value);
 568                 }
 569
 570                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 571                 {
 572                         return System.Convert.ToUInt64(m_value);
 573                 }
 574         }
 575 }