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                 public static double Parse (string s, NumberStyles style, IFormatProvider provider)
 116                 {
 117                         if (s == null) throw new ArgumentNullException();
 118                         if (style > NumberStyles.Any)
 119                         {
 120                                 throw new ArgumentException();
 121                         }
 122                         NumberFormatInfo format = NumberFormatInfo.GetInstance(provider);
 123                         if (format == null) throw new Exception("How did this happen?");
 124                         if (s == format.NaNSymbol) return Double.NaN;
 125                         if (s == format.PositiveInfinitySymbol) return Double.PositiveInfinity;
 126                         if (s == format.NegativeInfinitySymbol) return Double.NegativeInfinity;
 127
 128                         //
 129                         // validate and prepare string for C
 130                         //
 131                         int len = s.Length;
 132                         byte [] b = new byte [len + 1];
 133                         int didx = 0;
 134                         int sidx = 0;
 135                         char c;
 136
 137                         if ((style & NumberStyles.AllowLeadingWhite) != 0){
 138                                 while (sidx < len && Char.IsWhiteSpace (c = s [sidx]))
 139                                        sidx++;
 140
 141                                 if (sidx == len)
 142                                         throw new FormatException();
 143                         }
 144
 145                         bool allow_trailing_white = ((style & NumberStyles.AllowTrailingWhite) != 0);
 146
 147                         //
 148                         // Machine state
 149                         //
 150                         State state = State.AllowSign;
 151
 152                         //
 153                         // Setup
 154                         //
 155                         string decimal_separator = null;
 156                         int decimal_separator_len = 0;
 157                         if ((style & NumberStyles.AllowDecimalPoint) != 0){
 158                                 decimal_separator = format.NumberDecimalSeparator;
 159                                 decimal_separator_len = decimal_separator.Length;
 160                         }
 161                         string positive = format.PositiveSign;
 162                         string negative = format.NegativeSign;
 163
 164                         for (; sidx < len; sidx++){
 165                                 c = s [sidx];
 166
 167                                 switch (state){
 168                                 case State.AllowSign:
 169                                         if ((style & NumberStyles.AllowLeadingSign) != 0){
 170                                                 if (c == positive [0] &&
 171                                                     s.Substring (sidx, positive.Length) == positive){
 172                                                         state = State.Digits;
 173                                                         sidx += positive.Length-1;
 174                                                         continue;
 175                                                 }
 176
 177                                                 if (c == negative [0] &&
 178                                                     s.Substring (sidx, negative.Length) == negative){
 179                                                         state = State.Digits;
 180                                                         b [didx++] = (byte) '-';
 181                                                         sidx += negative.Length-1;
 182                                                         continue;
 183                                                 }
 184                                         }
 185                                         state = State.Digits;
 186                                         goto case State.Digits;
 187
 188                                 case State.Digits:
 189                                         if (Char.IsDigit (c)){
 190                                                 b [didx++] = (byte) c;
 191                                                 break;
 192                                         }
 193                                         if (c == 'e' || c == 'E')
 194                                                 goto case State.Decimal;
 195
 196                                         if (decimal_separator != null &&
 197                                             decimal_separator [0] == c){
 198                                                 if (s.Substring (sidx, decimal_separator_len) ==
 199                                                     decimal_separator){
 200                                                         b [didx++] = (byte) '.';
 201                                                         sidx += decimal_separator_len-1;
 202                                                         state = State.Decimal;
 203                                                         break;
 204                                                 }
 205                                         }
 206
 207                                         if (Char.IsWhiteSpace (c))
 208                                                 goto case State.ConsumeWhiteSpace;
 209
 210                                         throw new FormatException ("Unknown char: " + c);
 211
 212                                 case State.Decimal:
 213                                         if (Char.IsDigit (c)){
 214                                                 b [didx++] = (byte) c;
 215                                                 break;
 216                                         }
 217
 218                                         if (c == 'e' || c == 'E'){
 219                                                 if ((style & NumberStyles.AllowExponent) == 0)
 220                                                         throw new FormatException ("Unknown char: " + c);
 221                                                 b [didx++] = (byte) c;
 222                                                 state = State.ExponentSign;
 223                                                 break;
 224                                         }
 225
 226                                         if (Char.IsWhiteSpace (c))
 227                                                 goto case State.ConsumeWhiteSpace;
 228                                         throw new FormatException ("Unknown char: " + c);
 229
 230                                 case State.ExponentSign:
 231                                         if (Char.IsDigit (c)){
 232                                                 state = State.Exponent;
 233                                                 goto case State.Exponent;
 234                                         }
 235
 236                                         if (c == positive [0] &&
 237                                             s.Substring (sidx, positive.Length) == positive){
 238                                                 state = State.Digits;
 239                                                 sidx += positive.Length-1;
 240                                                 continue;
 241                                         }
 242
 243                                         if (c == negative [0] &&
 244                                             s.Substring (sidx, negative.Length) == negative){
 245                                                 state = State.Digits;
 246                                                 b [didx++] = (byte) '-';
 247                                                 sidx += negative.Length-1;
 248                                                 continue;
 249                                         }
 250
 251                                         if (Char.IsWhiteSpace (c))
 252                                                 goto case State.ConsumeWhiteSpace;
 253
 254                                         throw new FormatException ("Unknown char: " + c);
 255
 256                                 case State.Exponent:
 257                                         if (Char.IsDigit (c)){
 258                                                 b [didx++] = (byte) c;
 259                                                 break;
 260                                         }
 261
 262                                         if (Char.IsWhiteSpace (c))
 263                                                 goto case State.ConsumeWhiteSpace;
 264                                         throw new FormatException ("Unknown char: " + c);
 265
 266                                 case State.ConsumeWhiteSpace:
 267                                         if (allow_trailing_white && Char.IsWhiteSpace (c))
 268                                                 break;
 269                                         throw new FormatException ("Unknown char");
 270                                 }
 271                         }
 272
 273                         b [didx] = 0;
 274                         unsafe {
 275                                 fixed (byte *p = &b [0]){
 276                                         return ParseImpl (p);
 277                                 }
 278                         }
 279                 }
 280
 281                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 282                 unsafe private static extern double ParseImpl (byte *byte_ptr);
 283
 284                 public override string ToString ()
 285                 {
 286                         return ToString (null, null);
 287                 }
 288
 289                 public string ToString (IFormatProvider fp)
 290                 {
 291                         return ToString (null, fp);
 292                 }
 293
 294                 public string ToString (string format)
 295                 {
 296                         return ToString (format, null);
 297                 }
 298
 299                 [MonoTODO]
 300                 public string ToString (string format, IFormatProvider fp)
 301                 {
 302                         // FIXME: Need to pass format and provider info to this call too.
 303                         return ToStringImpl(value);
 304                 }
 305
 306                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
 307                 private static extern string ToStringImpl (double value);
 308
 309                 // =========== IConvertible Methods =========== //
 310
 311                 public TypeCode GetTypeCode ()
 312                 {
 313                         return TypeCode.Double;
 314                 }
 315
 316                 object IConvertible.ToType (Type conversionType, IFormatProvider provider)
 317                 {
 318                         return System.Convert.ToType(value, conversionType, provider);
 319                 }
 320
 321                 bool IConvertible.ToBoolean (IFormatProvider provider)
 322                 {
 323                         return System.Convert.ToBoolean(value);
 324                 }
 325
 326                 byte IConvertible.ToByte (IFormatProvider provider)
 327                 {
 328                         return System.Convert.ToByte(value);
 329                 }
 330
 331                 char IConvertible.ToChar (IFormatProvider provider)
 332                 {
 333                         throw new InvalidCastException();
 334                 }
 335
 336                 [CLSCompliant(false)]
 337                 DateTime IConvertible.ToDateTime (IFormatProvider provider)
 338                 {
 339                         throw new InvalidCastException();
 340                 }
 341
 342                 decimal IConvertible.ToDecimal (IFormatProvider provider)
 343                 {
 344                         return System.Convert.ToDecimal(value);
 345                 }
 346
 347                 double IConvertible.ToDouble (IFormatProvider provider)
 348                 {
 349                         return System.Convert.ToDouble(value);
 350                 }
 351
 352                 short IConvertible.ToInt16 (IFormatProvider provider)
 353                 {
 354                         return System.Convert.ToInt16(value);
 355                 }
 356
 357                 int IConvertible.ToInt32 (IFormatProvider provider)
 358                 {
 359                         return System.Convert.ToInt32(value);
 360                 }
 361
 362                 long IConvertible.ToInt64 (IFormatProvider provider)
 363                 {
 364                         return System.Convert.ToInt64(value);
 365                 }
 366
 367                 [CLSCompliant(false)]
 368                 sbyte IConvertible.ToSByte (IFormatProvider provider)
 369                 {
 370                         return System.Convert.ToSByte(value);
 371                 }
 372
 373                 float IConvertible.ToSingle (IFormatProvider provider)
 374                 {
 375                         return System.Convert.ToSingle(value);
 376                 }
 377
 378 /*
 379                 string IConvertible.ToString (IFormatProvider provider)
 380                 {
 381                         return ToString(provider);
 382                 }
 383 */
 384
 385                 [CLSCompliant(false)]
 386                 ushort IConvertible.ToUInt16 (IFormatProvider provider)
 387                 {
 388                         return System.Convert.ToUInt16(value);
 389                 }
 390
 391                 [CLSCompliant(false)]
 392                 uint IConvertible.ToUInt32 (IFormatProvider provider)
 393                 {
 394                         return System.Convert.ToUInt32(value);
 395                 }
 396
 397                 [CLSCompliant(false)]
 398                 ulong IConvertible.ToUInt64 (IFormatProvider provider)
 399                 {
 400                         return System.Convert.ToUInt64(value);
 401                 }
 402         }
 403 }