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