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 (s.Length == 0) {
 224                                 if (!tryParse)
 225                                         exc = new FormatException ();
 226                                 return false;
 227                         }
 228 #if NET_2_0
 229                         // yes it's counter intuitive (buggy?) but even TryParse actually throws in this case
 230                         if ((style & NumberStyles.AllowHexSpecifier) != 0) {
 231                                 string msg = Locale.GetText ("Double doesn't support parsing with '{0}'.", "AllowHexSpecifier");
 232                                 throw new ArgumentException (msg);
 233                         }
 234 #endif
 235                         if (style > NumberStyles.Any) {
 236                                 if (!tryParse)
 237                                         exc = new ArgumentException();
 238                                 return false;
 239                         }
 240
 241                         NumberFormatInfo format = NumberFormatInfo.GetInstance(provider);
 242                         if (format == null) throw new Exception("How did this happen?");
 243
 244                         if (s == format.NaNSymbol) {
 245                                 result = Double.NaN;
 246                                 return true;
 247                         }
 248                         if (s == format.PositiveInfinitySymbol) {
 249                                 result = Double.PositiveInfinity;
 250                                 return true;
 251                         }
 252                         if (s == format.NegativeInfinitySymbol) {
 253                                 result = Double.NegativeInfinity;
 254                                 return true;
 255                         }
 256
 257                         //
 258                         // validate and prepare string for C
 259                         //
 260                         int len = s.Length;
 261                         byte [] b = new byte [len + 1];
 262                         int didx = 0;
 263                         int sidx = 0;
 264                         char c;
 265
 266                         if ((style & NumberStyles.AllowLeadingWhite) != 0){
 267                                 while (sidx < len && Char.IsWhiteSpace (c = s [sidx]))
 268                                        sidx++;
 269
 270                                 if (sidx == len) {
 271                                         if (!tryParse)
 272                                                 exc = Int32.GetFormatException ();
 273                                         return true;
 274                                 }
 275                         }
 276
 277                         bool allow_trailing_white = ((style & NumberStyles.AllowTrailingWhite) != 0);
 278
 279                         //
 280                         // Machine state
 281                         //
 282                         int state = State_AllowSign;
 283
 284                         //
 285                         // Setup
 286                         //
 287                         string decimal_separator = null;
 288                         string group_separator = null;
 289                         int decimal_separator_len = 0;
 290                         int group_separator_len = 0;
 291                         if ((style & NumberStyles.AllowDecimalPoint) != 0){
 292                                 decimal_separator = format.NumberDecimalSeparator;
 293                                 decimal_separator_len = decimal_separator.Length;
 294                         }
 295                         if ((style & NumberStyles.AllowThousands) != 0){
 296                                 group_separator = format.NumberGroupSeparator;
 297                                 group_separator_len = group_separator.Length;
 298                         }
 299                         string positive = format.PositiveSign;
 300                         string negative = format.NegativeSign;
 301
 302                         for (; sidx < len; sidx++){
 303                                 c = s [sidx];
 304
 305                                 if (c == '\0') {
 306                                         sidx = len;
 307                                         continue;
 308                                 }
 309                                 switch (state){
 310                                 case State_AllowSign:
 311                                         if ((style & NumberStyles.AllowLeadingSign) != 0){
 312                                                 if (c == positive [0] &&
 313                                                     s.Substring (sidx, positive.Length) == positive){
 314                                                         state = State_Digits;
 315                                                         sidx += positive.Length-1;
 316                                                         continue;
 317                                                 }
 318
 319                                                 if (c == negative [0] &&
 320                                                     s.Substring (sidx, negative.Length) == negative){
 321                                                         state = State_Digits;
 322                                                         b [didx++] = (byte) '-';
 323                                                         sidx += negative.Length-1;
 324                                                         continue;
 325                                                 }
 326                                         }
 327                                         state = State_Digits;
 328                                         goto case State_Digits;
 329
 330                                 case State_Digits:
 331                                         if (Char.IsDigit (c)){
 332                                                 b [didx++] = (byte) c;
 333                                                 break;
 334                                         }
 335                                         if (c == 'e' || c == 'E')
 336                                                 goto case State_Decimal;
 337
 338                                         if (decimal_separator != null &&
 339                                             decimal_separator [0] == c){
 340                                                 if (s.Substring (sidx, decimal_separator_len) ==
 341                                                     decimal_separator){
 342                                                         b [didx++] = (byte) '.';
 343                                                         sidx += decimal_separator_len-1;
 344                                                         state = State_Decimal;
 345                                                         break;
 346                                                 }
 347                                         }
 348                                         if (group_separator != null &&
 349                                             group_separator [0] == c){
 350                                                 if (s.Substring (sidx, group_separator_len) ==
 351                                                     group_separator){
 352                                                         sidx += group_separator_len-1;
 353                                                         state = State_Digits;
 354                                                         break;
 355                                                 }
 356                                         }
 357
 358                                         if (Char.IsWhiteSpace (c))
 359                                                 goto case State_ConsumeWhiteSpace;
 360
 361                                         if (!tryParse)
 362                                                 exc = new FormatException ("Unknown char: " + c);
 363                                         return false;
 364
 365                                 case State_Decimal:
 366                                         if (Char.IsDigit (c)){
 367                                                 b [didx++] = (byte) c;
 368                                                 break;
 369                                         }
 370
 371                                         if (c == 'e' || c == 'E'){
 372                                                 if ((style & NumberStyles.AllowExponent) == 0)
 373                                                         throw new FormatException ("Unknown char: " + c);
 374                                                 b [didx++] = (byte) c;
 375                                                 state = State_ExponentSign;
 376                                                 break;
 377                                         }
 378
 379                                         if (Char.IsWhiteSpace (c))
 380                                                 goto case State_ConsumeWhiteSpace;
 381
 382                                         if (!tryParse)
 383                                                 exc = new FormatException ("Unknown char: " + c);
 384                                         return false;
 385
 386                                 case State_ExponentSign:
 387                                         if (Char.IsDigit (c)){
 388                                                 state = State_Exponent;
 389                                                 goto case State_Exponent;
 390                                         }
 391
 392                                         if (c == positive [0] &&
 393                                             s.Substring (sidx, positive.Length) == positive){
 394                                                 state = State_Digits;
 395                                                 sidx += positive.Length-1;
 396                                                 continue;
 397                                         }
 398
 399                                         if (c == negative [0] &&
 400                                             s.Substring (sidx, negative.Length) == negative){
 401                                                 state = State_Digits;
 402                                                 b [didx++] = (byte) '-';
 403                                                 sidx += negative.Length-1;
 404                                                 continue;
 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_Exponent:
 415                                         if (Char.IsDigit (c)){
 416                                                 b [didx++] = (byte) c;
 417                                                 break;
 418                                         }
 419
 420                                         if (Char.IsWhiteSpace (c))
 421                                                 goto case State_ConsumeWhiteSpace;
 422
 423                                         if (!tryParse)
 424                                                 exc = new FormatException ("Unknown char: " + c);
 425                                         return false;
 426
 427                                 case State_ConsumeWhiteSpace:
 428                                         if (allow_trailing_white && Char.IsWhiteSpace (c))
 429                                                 break;
 430
 431                                         if (!tryParse)
 432                                                 exc = new FormatException ("Unknown char");
 433                                         return false;
 434                                 }
 435                         }
 436
 437                         b [didx] = 0;
 438                         unsafe {
 439                                 fixed (byte *p = &b [0]){
 440                                         double retVal;
 441                                         if (!ParseImpl (p, out retVal)) {
 442                                                 if (!tryParse)
 443                                                         exc = Int32.GetFormatException ();
 444                                                 return false;
 445                                         }
 446                                         if (IsPositiveInfinity(retVal) || IsNegativeInfinity(retVal)) {
 447                                                 if (!tryParse)
 448                                                         exc = new OverflowException ();
 449                                                 return false;
 450                                         }
 451
 452                                         result = retVal;
 453                                         return true;
 454                                 }
 455                         }
 456                 }
 457
 458                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 459                 unsafe private static extern bool ParseImpl (byte *byte_ptr, out double value);
 460
 461                 public static bool TryParse (string s,
 462                                              NumberStyles style,
 463                                              IFormatProvider provider,
 464                                              out double result)
 465                 {
 466                         Exception exc;
 467                         if (!Parse (s, style, provider, true, out result, out exc)) {
 468                                 result = 0;
 469                                 return false;
 470                         }
 471
 472                         return true;
 473                 }
 474 #if NET_2_0
 475                 public static bool TryParse (string s, out double result)
 476                 {
 477                         return TryParse (s, NumberStyles.Any, null, out result);
 478                 }
 479 #endif
 480                 public override string ToString ()
 481                 {
 482                         return ToString (null, null);
 483                 }
 484
 485                 public string ToString (IFormatProvider fp)
 486                 {
 487                         return ToString (null, fp);
 488                 }
 489
 490                 public string ToString (string format)
 491                 {
 492                         return ToString (format, null);
 493                 }
 494
 495                 public string ToString (string format, IFormatProvider fp)
 496                 {
 497                         NumberFormatInfo nfi = NumberFormatInfo.GetInstance (fp);
 498                         return NumberFormatter.NumberToString (format, m_value, nfi);
 499                 }
 500
 501                 // =========== IConvertible Methods =========== //
 502
 503                 public TypeCode GetTypeCode ()
 504                 {
 505                         return TypeCode.Double;
 506                 }
 507
 508                 object IConvertible.ToType (Type conversionType, IFormatProvider provider)
 509                 {
 510                         return System.Convert.ToType(m_value, conversionType, provider);
 511                 }
 512
 513                 bool IConvertible.ToBoolean (IFormatProvider provider)
 514                 {
 515                         return System.Convert.ToBoolean(m_value);
 516                 }
 517
 518                 byte IConvertible.ToByte (IFormatProvider provider)
 519                 {
 520                         return System.Convert.ToByte(m_value);
 521                 }
 522
 523                 char IConvertible.ToChar (IFormatProvider provider)
 524                 {
 525                         throw new InvalidCastException();
 526                 }
 527
 528                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 529                 {
 530                         throw new InvalidCastException();
 531                 }
 532
 533                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 534                 {
 535                         return System.Convert.ToDecimal(m_value);
 536                 }
 537
 538                 double IConvertible.ToDouble (IFormatProvider provider)
 539                 {
 540                         return System.Convert.ToDouble(m_value);
 541                 }
 542
 543                 short IConvertible.ToInt16 (IFormatProvider provider)
 544                 {
 545                         return System.Convert.ToInt16(m_value);
 546                 }
 547
 548                 int IConvertible.ToInt32 (IFormatProvider provider)
 549                 {
 550                         return System.Convert.ToInt32(m_value);
 551                 }
 552
 553                 long IConvertible.ToInt64 (IFormatProvider provider)
 554                 {
 555                         return System.Convert.ToInt64(m_value);
 556                 }
 557
 558                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 559                 {
 560                         return System.Convert.ToSByte(m_value);
 561                 }
 562
 563                 float IConvertible.ToSingle (IFormatProvider provider)
 564                 {
 565                         return System.Convert.ToSingle(m_value);
 566                 }
 567
 568 /*
 569                 string IConvertible.ToString (IFormatProvider provider)
 570                 {
 571                         return ToString(provider);
 572                 }
 573 */
 574
 575                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 576                 {
 577                         return System.Convert.ToUInt16(m_value);
 578                 }
 579
 580                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 581                 {
 582                         return System.Convert.ToUInt32(m_value);
 583                 }
 584
 585                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 586                 {
 587                         return System.Convert.ToUInt64(m_value);
 588                 }
 589         }
 590 }