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 using System.Globalization;
  13 using System.Runtime.CompilerServices;
  14
  15 namespace System {
  16
  17         [Serializable]
  18         public struct Double : IComparable, IFormattable, IConvertible {
  19                 public const double Epsilon = 4.9406564584124650e-324;
  20                 public const double MaxValue =  1.7976931348623157e308;
  21                 public const double MinValue = -1.7976931348623157e308;
  22                 public const double NaN = 0.0d / 0.0d;
  23                 public const double NegativeInfinity = -1.0d / 0.0d;
  24                 public const double PositiveInfinity = 1.0d / 0.0d;
  25
  26                 // VES needs to know about value.  public is workaround
  27                 // so source will compile
  28                 public double value;
  29
  30                 public int CompareTo (object v)
  31                 {
  32                         if (v == null)
  33                                 return 1;
  34
  35                         if (!(v is System.Double))
  36                                 throw new ArgumentException (Locale.GetText ("Value is not a System.Double"));
  37
  38                         if (IsPositiveInfinity(value) && IsPositiveInfinity((double) v)){
  39                                 return 0;
  40                         }
  41
  42                         if (IsNegativeInfinity(value) && IsNegativeInfinity((double) v)){
  43                                 return 0;
  44                         }
  45
  46                         if (IsNaN((double) v)) {
  47                                 if (IsNaN(value))
  48                                         return 0;
  49                                 else
  50                                         return 1;
  51                         }
  52
  53                         return (int) (value - ((double) v));
  54                 }
  55
  56                 public override bool Equals (object o)
  57                 {
  58                         if (!(o is System.Double))
  59                                 return false;
  60
  61                         if (IsNaN ((double)o)) {
  62                                 if (IsNaN(value))
  63                                         return true;
  64                                 else
  65                                         return false;
  66                         }
  67
  68                         return ((double) o) == value;
  69                 }
  70
  71                 public override int GetHashCode ()
  72                 {
  73                         return (int) value;
  74                 }
  75
  76                 public static bool IsInfinity (double d)
  77                 {
  78                         return (d == PositiveInfinity || d == NegativeInfinity);
  79                 }
  80
  81                 public static bool IsNaN (double d)
  82                 {
  83                         return (d != d);
  84                 }
  85
  86                 public static bool IsNegativeInfinity (double d)
  87                 {
  88                         return (d < 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
  89                 }
  90
  91                 public static bool IsPositiveInfinity (double d)
  92                 {
  93                         return (d > 0.0d && (d == NegativeInfinity || d == PositiveInfinity));
  94                 }
  95
  96                 public static double Parse (string s)
  97                 {
  98                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), null);
  99                 }
 100
 101                 public static double Parse (string s, IFormatProvider fp)
 102                 {
 103                         return Parse (s, (NumberStyles.Float | NumberStyles.AllowThousands), fp);
 104                 }
 105
 106                 public static double Parse (string s, NumberStyles style)
 107                 {
 108                         return Parse (s, style, null);
 109                 }
 110
 111                 enum State {
 112                         AllowSign, Digits, Decimal, ExponentSign, Exponent, ConsumeWhiteSpace
 113                 }
 114
 115                 [MonoTODO("check if digits are group in correct numbers between the group separators")]
 116                 public static double Parse (string s, NumberStyles style, IFormatProvider provider)
 117                 {
 118                         if (s == null) throw new ArgumentNullException();
 119                         if (style > NumberStyles.Any)
 120                         {
 121                                 throw new ArgumentException();
 122                         }
 123                         NumberFormatInfo format = NumberFormatInfo.GetInstance(provider);
 124                         if (format == null) throw new Exception("How did this happen?");
 125                         if (s == format.NaNSymbol) return Double.NaN;
 126                         if (s == format.PositiveInfinitySymbol) return Double.PositiveInfinity;
 127                         if (s == format.NegativeInfinitySymbol) return Double.NegativeInfinity;
 128
 129                         //
 130                         // validate and prepare string for C
 131                         //
 132                         int len = s.Length;
 133                         byte [] b = new byte [len + 1];
 134                         int didx = 0;
 135                         int sidx = 0;
 136                         char c;
 137
 138                         if ((style & NumberStyles.AllowLeadingWhite) != 0){
 139                                 while (sidx < len && Char.IsWhiteSpace (c = s [sidx]))
 140                                        sidx++;
 141
 142                                 if (sidx == len)
 143                                         throw new FormatException();
 144                         }
 145
 146                         bool allow_trailing_white = ((style & NumberStyles.AllowTrailingWhite) != 0);
 147
 148                         //
 149                         // Machine state
 150                         //
 151                         State state = State.AllowSign;
 152
 153                         //
 154                         // Setup
 155                         //
 156                         string decimal_separator = null;
 157                         string group_separator = null;
 158                         int decimal_separator_len = 0;
 159                         int group_separator_len = 0;
 160                         if ((style & NumberStyles.AllowDecimalPoint) != 0){
 161                                 decimal_separator = format.NumberDecimalSeparator;
 162                                 decimal_separator_len = decimal_separator.Length;
 163                         }
 164                         if ((style & NumberStyles.AllowThousands) != 0){
 165                                 group_separator = format.NumberGroupSeparator;
 166                                 group_separator_len = group_separator.Length;
 167                         }
 168                         string positive = format.PositiveSign;
 169                         string negative = format.NegativeSign;
 170
 171                         for (; sidx < len; sidx++){
 172                                 c = s [sidx];
 173
 174                                 switch (state){
 175                                 case State.AllowSign:
 176                                         if ((style & NumberStyles.AllowLeadingSign) != 0){
 177                                                 if (c == positive [0] &&
 178                                                     s.Substring (sidx, positive.Length) == positive){
 179                                                         state = State.Digits;
 180                                                         sidx += positive.Length-1;
 181                                                         continue;
 182                                                 }
 183
 184                                                 if (c == negative [0] &&
 185                                                     s.Substring (sidx, negative.Length) == negative){
 186                                                         state = State.Digits;
 187                                                         b [didx++] = (byte) '-';
 188                                                         sidx += negative.Length-1;
 189                                                         continue;
 190                                                 }
 191                                         }
 192                                         state = State.Digits;
 193                                         goto case State.Digits;
 194
 195                                 case State.Digits:
 196                                         if (Char.IsDigit (c)){
 197                                                 b [didx++] = (byte) c;
 198                                                 break;
 199                                         }
 200                                         if (c == 'e' || c == 'E')
 201                                                 goto case State.Decimal;
 202
 203                                         if (decimal_separator != null &&
 204                                             decimal_separator [0] == c){
 205                                                 if (s.Substring (sidx, decimal_separator_len) ==
 206                                                     decimal_separator){
 207                                                         b [didx++] = (byte) '.';
 208                                                         sidx += decimal_separator_len-1;
 209                                                         state = State.Decimal;
 210                                                         break;
 211                                                 }
 212                                         }
 213                                         if (group_separator != null &&
 214                                             group_separator [0] == c){
 215                                                 if (s.Substring (sidx, group_separator_len) ==
 216                                                     group_separator){
 217                                                         sidx += group_separator_len-1;
 218                                                         state = State.Digits;
 219                                                         break;
 220                                                 }
 221                                         }
 222
 223                                         if (Char.IsWhiteSpace (c))
 224                                                 goto case State.ConsumeWhiteSpace;
 225
 226                                         throw new FormatException ("Unknown char: " + c);
 227
 228                                 case State.Decimal:
 229                                         if (Char.IsDigit (c)){
 230                                                 b [didx++] = (byte) c;
 231                                                 break;
 232                                         }
 233
 234                                         if (c == 'e' || c == 'E'){
 235                                                 if ((style & NumberStyles.AllowExponent) == 0)
 236                                                         throw new FormatException ("Unknown char: " + c);
 237                                                 b [didx++] = (byte) c;
 238                                                 state = State.ExponentSign;
 239                                                 break;
 240                                         }
 241
 242                                         if (Char.IsWhiteSpace (c))
 243                                                 goto case State.ConsumeWhiteSpace;
 244                                         throw new FormatException ("Unknown char: " + c);
 245
 246                                 case State.ExponentSign:
 247                                         if (Char.IsDigit (c)){
 248                                                 state = State.Exponent;
 249                                                 goto case State.Exponent;
 250                                         }
 251
 252                                         if (c == positive [0] &&
 253                                             s.Substring (sidx, positive.Length) == positive){
 254                                                 state = State.Digits;
 255                                                 sidx += positive.Length-1;
 256                                                 continue;
 257                                         }
 258
 259                                         if (c == negative [0] &&
 260                                             s.Substring (sidx, negative.Length) == negative){
 261                                                 state = State.Digits;
 262                                                 b [didx++] = (byte) '-';
 263                                                 sidx += negative.Length-1;
 264                                                 continue;
 265                                         }
 266
 267                                         if (Char.IsWhiteSpace (c))
 268                                                 goto case State.ConsumeWhiteSpace;
 269
 270                                         throw new FormatException ("Unknown char: " + c);
 271
 272                                 case State.Exponent:
 273                                         if (Char.IsDigit (c)){
 274                                                 b [didx++] = (byte) c;
 275                                                 break;
 276                                         }
 277
 278                                         if (Char.IsWhiteSpace (c))
 279                                                 goto case State.ConsumeWhiteSpace;
 280                                         throw new FormatException ("Unknown char: " + c);
 281
 282                                 case State.ConsumeWhiteSpace:
 283                                         if (allow_trailing_white && Char.IsWhiteSpace (c))
 284                                                 break;
 285                                         throw new FormatException ("Unknown char");
 286                                 }
 287                         }
 288
 289                         b [didx] = 0;
 290                         unsafe {
 291                                 fixed (byte *p = &b [0]){
 292                                         double retVal = ParseImpl (p);
 293                                         if (IsPositiveInfinity(retVal) || IsNegativeInfinity(retVal))
 294                                                 throw new OverflowException();
 295
 296                                         return retVal;
 297                                 }
 298                         }
 299                 }
 300
 301                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 302                 unsafe private static extern double ParseImpl (byte *byte_ptr);
 303
 304                 public override string ToString ()
 305                 {
 306                         return ToString (null, null);
 307                 }
 308
 309                 public string ToString (IFormatProvider fp)
 310                 {
 311                         return ToString (null, fp);
 312                 }
 313
 314                 public string ToString (string format)
 315                 {
 316                         return ToString (format, null);
 317                 }
 318
 319                 [MonoTODO]
 320                 public string ToString (string format, IFormatProvider fp)
 321                 {
 322                         // FIXME: Need to pass format and provider info to this call too.
 323                         return ToStringImpl(value);
 324                 }
 325
 326                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 327                 private static extern string ToStringImpl (double value);
 328
 329                 // =========== IConvertible Methods =========== //
 330
 331                 public TypeCode GetTypeCode ()
 332                 {
 333                         return TypeCode.Double;
 334                 }
 335
 336                 object IConvertible.ToType (Type conversionType, IFormatProvider provider)
 337                 {
 338                         return System.Convert.ToType(value, conversionType, provider);
 339                 }
 340
 341                 bool IConvertible.ToBoolean (IFormatProvider provider)
 342                 {
 343                         return System.Convert.ToBoolean(value);
 344                 }
 345
 346                 byte IConvertible.ToByte (IFormatProvider provider)
 347                 {
 348                         return System.Convert.ToByte(value);
 349                 }
 350
 351                 char IConvertible.ToChar (IFormatProvider provider)
 352                 {
 353                         throw new InvalidCastException();
 354                 }
 355
 356                 [CLSCompliant(false)]
 357                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 358                 {
 359                         throw new InvalidCastException();
 360                 }
 361
 362                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 363                 {
 364                         return System.Convert.ToDecimal(value);
 365                 }
 366
 367                 double IConvertible.ToDouble (IFormatProvider provider)
 368                 {
 369                         return System.Convert.ToDouble(value);
 370                 }
 371
 372                 short IConvertible.ToInt16 (IFormatProvider provider)
 373                 {
 374                         return System.Convert.ToInt16(value);
 375                 }
 376
 377                 int IConvertible.ToInt32 (IFormatProvider provider)
 378                 {
 379                         return System.Convert.ToInt32(value);
 380                 }
 381
 382                 long IConvertible.ToInt64 (IFormatProvider provider)
 383                 {
 384                         return System.Convert.ToInt64(value);
 385                 }
 386
 387                 [CLSCompliant(false)]
 388                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 389                 {
 390                         return System.Convert.ToSByte(value);
 391                 }
 392
 393                 float IConvertible.ToSingle (IFormatProvider provider)
 394                 {
 395                         return System.Convert.ToSingle(value);
 396                 }
 397
 398 /*
 399                 string IConvertible.ToString (IFormatProvider provider)
 400                 {
 401                         return ToString(provider);
 402                 }
 403 */
 404
 405                 [CLSCompliant(false)]
 406                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 407                 {
 408                         return System.Convert.ToUInt16(value);
 409                 }
 410
 411                 [CLSCompliant(false)]
 412                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 413                 {
 414                         return System.Convert.ToUInt32(value);
 415                 }
 416
 417                 [CLSCompliant(false)]
 418                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 419                 {
 420                         return System.Convert.ToUInt64(value);
 421                 }
 422         }
 423 }