mcs/class/corlib/System/String.cs

   1 //
   2 // System.String.cs
   3 //
   4 // Authors:
   5 //        Patrik Torstensson (patrik.torstensson@labs2.com)
   6 //   Jeffrey Stedfast (fejj@ximian.com)
   7 //   Dan Lewis (dihlewis@yahoo.co.uk)
   8 //
   9 // (C) 2001 Ximian, Inc.  http://www.ximian.com
  10 //
  11
  12 using System;
  13 using System.Text;
  14 using System.Collections;
  15 using System.Globalization;
  16 using System.Runtime.CompilerServices;
  17
  18 namespace System {
  19         public sealed class String : IConvertible, IComparable, ICloneable, IEnumerable {
  20                 private int length;
  21
  22                 public static readonly String Empty = "";
  23
  24                 [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
  25                 unsafe public extern String(char *value);
  26
  27                 [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
  28                 unsafe public extern String(char *value, int sindex, int length);
  29
  30                 [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
  31                 unsafe public extern String(sbyte *value);
  32
  33                 [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
  34                 unsafe public extern String(sbyte *value, int sindex, int length);
  35
  36                 [CLSCompliant(false), MethodImplAttribute(MethodImplOptions.InternalCall)]
  37                 unsafe public extern String(sbyte *value, int sindex, int length, Encoding enc);
  38
  39                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  40                 public extern String(char [] val, int sindex, int length);
  41
  42                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  43                 public extern String(char [] val);
  44
  45                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  46                 public extern String(char c, int count);
  47
  48                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
  49                 public extern override int GetHashCode();
  50
  51                 public static bool Equals(String str1, String str2) {
  52                         if ((Object) str1 == (Object) str2)
  53                                 return true;
  54
  55                         if (null == (Object) str1 || null == (Object) str2)
  56                                 return false;
  57
  58                         if (str1.length != str2.length)
  59                                 return false;
  60
  61                         return InternalEquals(str1, str2);
  62                 }
  63
  64                 public static bool operator == (String str1, String str2) {
  65                         return Equals(str1, str2);
  66                 }
  67
  68                 public static bool operator != (String str1, String str2) {
  69                         return !Equals(str1, str2);
  70                 }
  71
  72                 public override bool Equals(Object obj) {
  73                         if (null == obj)
  74                                 return false;
  75
  76                         if (!(obj is String))
  77                                 return false;
  78
  79                         return InternalEquals(this, (String) obj);
  80                 }
  81
  82                 public bool Equals(String value) {
  83                         if (null == value)
  84                                 return false;
  85
  86                         if (length != value.length)
  87                                 return false;
  88
  89                         return InternalEquals(this, value);
  90                 }
  91
  92                 [IndexerName("Chars")]
  93                 public extern char this[int index] {
  94                         [MethodImplAttribute(MethodImplOptions.InternalCall)]
  95                         get;
  96                 }
  97
  98                 public Object Clone() {
  99                         return this;
 100                 }
 101
 102                 public TypeCode GetTypeCode () {
 103                         return TypeCode.String;
 104                 }
 105
 106                 public void CopyTo(int sindex, char[] dest, int dindex, int count) {
 107                         // LAMESPEC: should I null-terminate?
 108
 109                         if (dest == null)
 110                                 throw new ArgumentNullException();
 111
 112                         if (sindex < 0 || dindex < 0 || count < 0)
 113                                 throw new ArgumentOutOfRangeException ();
 114
 115                         if (sindex + count > Length)
 116                                 throw new ArgumentOutOfRangeException ();
 117
 118                         if (dindex + count > dest.Length)
 119                                 throw new ArgumentOutOfRangeException ();
 120
 121                         InternalCopyTo(sindex, dest, dindex, count);
 122                 }
 123
 124                 public char[] ToCharArray() {
 125                         return ToCharArray(0, length);
 126                 }
 127
 128                 public char[] ToCharArray(int sindex, int length) {
 129                         if (sindex < 0 || length < 0 || sindex + length > this.length)
 130                                 throw new ArgumentOutOfRangeException ();
 131
 132                         char [] tmp = new char[length];
 133
 134                         InternalCopyTo(sindex, tmp, 0, length);
 135
 136                         return tmp;
 137                 }
 138
 139                 public String [] Split(params char [] separator) {
 140                         return Split(separator, Int32.MaxValue);
 141                 }
 142
 143                 public String[] Split(char[] separator, int count) {
 144                         if (null == separator) {
 145                                 separator = WhiteChars;
 146                         }
 147
 148                         if (count < 0)
 149                                 throw new ArgumentOutOfRangeException ();
 150
 151                         if (count == 0)
 152                                 return new String[1] { ToString() };
 153
 154                         return InternalSplit(separator, count);
 155                 }
 156
 157                 public String Substring (int sindex) {
 158                         if (sindex < 0 || sindex > this.length) {
 159                                 throw new ArgumentOutOfRangeException();
 160                         }
 161
 162                         string tmp = InternalAllocateStr(this.length - sindex);
 163                         InternalStrcpy(tmp, 0, this, sindex, length - sindex);
 164
 165                         return tmp;
 166                 }
 167
 168                 public String Substring (int sindex, int length) {
 169                         if (length < 0 || sindex < 0 || sindex + length > this.length) {
 170                                 throw new ArgumentOutOfRangeException();
 171                         }
 172
 173                         if (length == 0)
 174                                 return String.Empty;
 175
 176                         string tmp = InternalAllocateStr(length);
 177                         InternalStrcpy(tmp, 0, this, sindex, length);
 178
 179                         return tmp;
 180                 }
 181
 182                 private static readonly char[] WhiteChars = {  (char) 0x9, (char) 0xA, (char) 0xB, (char) 0xC, (char) 0xD, (char) 0x20, (char) 0xA0, (char) 0x2000, (char) 0x2001, (char) 0x2002, (char) 0x2003, (char) 0x2004, (char) 0x2005,
 183                                                                                                                                           (char) 0x2006, (char) 0x2007, (char) 0x2008, (char) 0x2009, (char) 0x200A, (char) 0x200B, (char) 0x3000, (char) 0xFEFF };
 184
 185                 public String Trim(params char[] chars) {
 186                         if (null == chars || chars.Length == 0)
 187                                 chars = WhiteChars;
 188
 189                         return InternalTrim(chars, 0);
 190                 }
 191
 192                 public String TrimStart(params char[] chars) {
 193                         if (null == chars || chars.Length == 0)
 194                                 chars = WhiteChars;
 195
 196                         return InternalTrim(chars, 1);
 197                 }
 198
 199                 public String TrimEnd(params char[] chars) {
 200                         if (null == chars || chars.Length == 0)
 201                                 chars = WhiteChars;
 202
 203                         return InternalTrim(chars, 2);
 204                 }
 205
 206                 public static int Compare(String s1, String s2) {
 207                         return Compare(s1, s2, false);
 208                 }
 209
 210                 public static int Compare(String s1, String s2, bool inCase) {
 211                         if (null == s1) {
 212                                 if (null == s2)
 213                                         return 0;
 214                                 else
 215                                         return -1;
 216                         } else if (null == s2)
 217                                 return 1;
 218
 219                         return InternalCompare(s1, 0, s2, 0, Math.Max(s1.length, s2.length), inCase);
 220                 }
 221
 222                 [MonoTODO()]
 223                 public static int Compare(String s1, String s2, bool inCase, CultureInfo culture) {
 224                         return Compare(s1, s2, inCase);
 225                 }
 226
 227                 public static int Compare(String s1, int i1, String s2, int i2, int length) {
 228                         return Compare(s1, i1, s2, i2, length, false);
 229                 }
 230
 231                 public static int Compare(String s1, int i1, String s2, int i2, int length, bool inCase) {
 232                         if (null == s1) {
 233                                 if (null == s2)
 234                                         return 0;
 235                                 else
 236                                         return -1;
 237                         } else if (null == s2)
 238                                 return 1;
 239
 240                         if (length < 0 || i1 < 0 || i2 < 0)
 241                                 throw new ArgumentOutOfRangeException ();
 242
 243                         if (i1 > s1.length || i2 > s2.length)
 244                                 throw new ArgumentOutOfRangeException ();
 245
 246                         if (length == 0)
 247                                 return 0;
 248
 249                         return InternalCompare(s1, i1, s2, i2, length, inCase);
 250                 }
 251
 252                 [MonoTODO()]
 253                 public static int Compare(String s1, int i1, String s2, int i2, int length, bool inCase, CultureInfo culture) {
 254                         return Compare(s1, i1, s2, i2, length, inCase);
 255                 }
 256
 257                 public int CompareTo(Object value) {
 258                         if (null == value)
 259                                 return 1;
 260
 261                         if (!(value is String))
 262                                 throw new ArgumentException();
 263
 264                         return String.Compare(this, (String) value, false);
 265                 }
 266
 267                 public int CompareTo(String str) {
 268                         if (null == str)
 269                                 return 1;
 270
 271                         return Compare(this, str, false);
 272                 }
 273
 274                 public static int CompareOrdinal(String s1, String s2) {
 275                         if (null == s1 || null == s2) {
 276                                 if ((Object)s1 == (Object) s2) {
 277                                         return 0;
 278                                 }
 279
 280                                 return (s1 == null) ? -1 : 1;
 281                         }
 282
 283                         return InternalCompare(s1, 0, s2, 0, Math.Max(s1.length, s2.length), false);
 284                 }
 285
 286                 public static int CompareOrdinal(String s1, int i1, String s2, int i2, int length) {
 287                         if (null == s1 || null == s2) {
 288                                 if ((Object)s1 == (Object) s2) {
 289                                         return 0;
 290                                 }
 291
 292                                 return (s1 == null) ? -1 : 1;
 293                         }
 294
 295                         if (i1 < 0 || i2 < 0 || length < 0)
 296                                 throw new ArgumentOutOfRangeException ();
 297
 298                         if (i1 > s1.length || i2 > s2.length)
 299                                 throw new ArgumentOutOfRangeException ();
 300
 301                         return InternalCompare(s1, i1, s2, i2, length, false);
 302                 }
 303
 304                 public bool EndsWith(String value) {
 305                         if (null == value)
 306                                 throw new ArgumentNullException();
 307
 308                         if (value.length > this.length) {
 309                                 return false;
 310                         }
 311
 312                         return (0 == Compare(this, length - value.length, value, 0, value.length));
 313                 }
 314
 315                 public int IndexOfAny(char [] arr) {
 316                         if (null == arr)
 317                                 throw new ArgumentNullException();
 318
 319                         return InternalIndexOfAny(arr, 0, this.length);
 320                 }
 321
 322                 public int IndexOfAny(char [] arr, int sindex) {
 323                         if (null == arr)
 324                                 throw new ArgumentNullException();
 325                         if (sindex < 0 || sindex >= this.length)
 326                                 throw new ArgumentOutOfRangeException();
 327
 328                         return InternalIndexOfAny(arr, sindex, this.length - sindex);
 329                 }
 330
 331                 public int IndexOfAny(char [] arr, int sindex, int count) {
 332                         if (null == arr)
 333                                 throw new ArgumentNullException();
 334                         if (sindex < 0 || count < 0 || sindex + count > this.length)
 335                                 throw new ArgumentOutOfRangeException ();
 336
 337                         return InternalIndexOfAny(arr, sindex, count);
 338                 }
 339
 340                 public int IndexOf(char value) {
 341                         return InternalIndexOf(value, 0, this.length);
 342                 }
 343
 344                 public int IndexOf(String value) {
 345                         return IndexOf(value, 0, this.length);
 346                 }
 347
 348                 public int IndexOf(char value, int sindex) {
 349                         if (sindex < 0 || sindex >= this.length) {
 350                                 throw new ArgumentOutOfRangeException();
 351                         }
 352
 353                         return InternalIndexOf(value, sindex, this.length - sindex);
 354                 }
 355
 356                 public int IndexOf(String value, int sindex) {
 357                         return IndexOf(value, sindex, this.length - sindex);
 358                 }
 359
 360                 public int IndexOf(char value, int sindex, int count) {
 361                         if (sindex < 0 || count < 0 || sindex + count > this.length)
 362                                 throw new ArgumentOutOfRangeException ();
 363
 364                         if (sindex == 0 && this.length == 0)
 365                                 return -1;
 366
 367                         return InternalIndexOf(value, sindex, count);
 368                 }
 369
 370                 public int IndexOf(String value, int sindex, int count) {
 371                         if (null == value)
 372                                 throw new ArgumentNullException();
 373
 374                         if (sindex < 0 || count < 0 || sindex + count > this.length)
 375                                 throw new ArgumentOutOfRangeException ();
 376
 377                         if (sindex == 0 && this.length == 0)
 378                                 return -1;
 379
 380                         return InternalIndexOf(value, sindex, count);
 381                 }
 382
 383                 public int LastIndexOfAny(char [] arr) {
 384                         if (null == arr)
 385                                 throw new ArgumentNullException();
 386
 387                         return InternalLastIndexOfAny(arr, this.length - 1, this.length);
 388                 }
 389
 390                 public int LastIndexOfAny(char [] arr, int sindex) {
 391                         if (null == arr)
 392                                 throw new ArgumentNullException();
 393
 394                         if (sindex < 0 || sindex > this.length)
 395                                 throw new ArgumentOutOfRangeException();
 396
 397                         if (this.length == 0)
 398                                 return -1;
 399
 400                         return InternalLastIndexOfAny(arr, sindex, sindex + 1);
 401                 }
 402
 403                 public int LastIndexOfAny(char [] arr, int sindex, int count) {
 404                         if (null == arr)
 405                                 throw new ArgumentNullException();
 406
 407                         if (sindex < 0 || count < 0 || sindex > this.length || sindex - count < -1)
 408                                 throw new ArgumentOutOfRangeException();
 409
 410                         if (this.length == 0)
 411                                 return -1;
 412
 413                         return InternalLastIndexOfAny(arr, sindex, count);
 414                 }
 415
 416                 public int LastIndexOf(char value) {
 417                         return InternalLastIndexOf(value, this.length - 1, this.length);
 418                 }
 419
 420                 public int LastIndexOf(String value) {
 421                         if (null == value)
 422                                 throw new ArgumentNullException();
 423                         \r
 424                         if (value.length == 0)\r
 425                                 return 0;\r
 426 \r
 427                         if (this.length == 0)\r
 428                                 return -1;\r
 429
 430                         return InternalLastIndexOf(value, this.length - 1, this.length);
 431                 }
 432
 433                 public int LastIndexOf(char value, int sindex){
 434                         return LastIndexOf(value, sindex, sindex + 1);
 435                 }
 436
 437                 public int LastIndexOf(String value, int sindex) {
 438                         return LastIndexOf(value, sindex, sindex + 1);
 439                 }
 440
 441                 public int LastIndexOf(char value, int sindex, int count) {
 442                         if (sindex < 0 || count < 0)\r
 443                                 throw new ArgumentOutOfRangeException ();\r
 444 \r
 445                         if (sindex >= this.length || sindex - count + 1 < 0)\r
 446                                 throw new ArgumentOutOfRangeException ();\r
 447
 448                         if (sindex == 0 && this.length == 0)
 449                                 return -1;
 450
 451                         return InternalLastIndexOf(value, sindex, count);
 452                 }
 453
 454                 public int LastIndexOf(String value, int sindex, int count) {
 455                         if (null == value)
 456                                 throw new ArgumentNullException();
 457
 458                         if (sindex < 0 || sindex > this.length)\r
 459                                 throw new ArgumentOutOfRangeException ();\r
 460
 461                         if (count < 0 || sindex - count + 1 < 0)\r
 462                                 throw new ArgumentOutOfRangeException ();\r
 463 \r
 464                         if (value.length > sindex)\r
 465                                 return -1;\r
 466
 467                         if (value == String.Empty)\r
 468                                 return sindex;\r
 469
 470                         if (sindex == 0 && this.length == 0)
 471                                 return -1;
 472
 473                         return InternalLastIndexOf(value, sindex, count);
 474                 }
 475
 476                 public String PadLeft(int width) {
 477                         return PadLeft(width, ' ');
 478                 }
 479
 480                 public String PadLeft(int width, char chr) {
 481                         if (width < 0)
 482                                 throw new ArgumentException();
 483
 484                         if (width < this.length)
 485                                 return String.Copy(this);
 486
 487                         return InternalPad(width, chr, false);
 488                 }
 489
 490                 public String PadRight(int width) {
 491                         return PadRight(width, ' ');
 492                 }
 493
 494                 public String PadRight(int width, char chr) {
 495                         if (width < 0)
 496                                 throw new ArgumentException();
 497
 498                         if (width < this.length)
 499                                 return String.Copy(this);
 500
 501                         return InternalPad(width, chr, true);
 502                 }
 503
 504                 public bool StartsWith(String value) {
 505                         if (null == value)
 506                                 throw new ArgumentNullException();
 507
 508                         if (this.length < value.length)
 509                                 return false;
 510
 511                         return (0 == Compare(this, 0, value, 0 , value.length));
 512                 }
 513
 514
 515                 public String Replace (char oldChar, char newChar) {
 516                         return InternalReplace(oldChar, newChar);
 517                 }
 518
 519                 public String Replace(String oldValue, String newValue) {
 520                         if (null == oldValue)
 521                                 throw new ArgumentNullException();
 522
 523                         return InternalReplace(oldValue, newValue);
 524                 }
 525
 526                 public String Remove(int sindex, int count) {
 527                         if (sindex < 0 || count < 0 || sindex + count > this.length)
 528                                 throw new ArgumentOutOfRangeException ();
 529
 530                         return InternalRemove(sindex, count);
 531                 }
 532
 533                 public String ToLower() {
 534                         return InternalToLower();
 535                 }
 536
 537                 public String ToLower(CultureInfo culture) {
 538                         throw new NotImplementedException();
 539                 }
 540
 541                 public String ToUpper() {
 542                         return InternalToUpper();
 543                 }
 544
 545                 public String ToUpper(CultureInfo culture) {
 546                         throw new NotImplementedException();
 547                 }
 548
 549                 public override String ToString() {
 550                         return this;
 551                 }
 552
 553                 public String ToString(IFormatProvider provider) {
 554                         return this;
 555                 }
 556
 557                 public String Trim() {
 558                         return Trim(null);
 559                 }
 560
 561                 public static String Format(String format, Object arg0) {
 562                         return Format(null, format, new Object[] {arg0});
 563                 }
 564
 565                 public static String Format(String format, Object arg0, Object arg1) {
 566                         return Format(null, format, new Object[] {arg0, arg1});
 567                 }
 568
 569                 public static String Format(String format, Object arg0, Object arg1, Object arg2) {
 570                         return Format(null, format, new Object[] {arg0, arg1, arg2});
 571                 }
 572
 573                 public static string Format (string format, params object[] args) {
 574                         return Format (null, format, args);
 575                 }
 576
 577                 public static string Format (IFormatProvider provider, string format, params object[] args) {
 578                         if (format == null || args == null)
 579                                 throw new ArgumentNullException ();
 580
 581                         StringBuilder result = new StringBuilder ();
 582
 583                         int ptr = 0;
 584                         int start = ptr;
 585                         while (ptr < format.length) {
 586                                 char c = format[ptr ++];
 587
 588                                 if (c == '{') {
 589                                         result.Append (format, start, ptr - start - 1);
 590
 591                                         // check for escaped open bracket
 592
 593                                         if (format[ptr] == '{') {
 594                                                 start = ptr ++;
 595                                                 continue;
 596                                         }
 597
 598                                         // parse specifier
 599
 600                                         int n, width;
 601                                         bool left_align;
 602                                         string arg_format;
 603
 604                                         ParseFormatSpecifier (format, ref ptr, out n, out width, out left_align, out arg_format);
 605                                         if (n >= args.Length)
 606                                                 throw new FormatException ("Index (zero based) must be greater than or equal to zero and less than the size of the argument list.");
 607
 608                                         // format argument
 609
 610                                         object arg = args[n];
 611
 612                                         string str;
 613                                         if (arg == null)
 614                                                 str = "";
 615                                         else if (arg is IFormattable)
 616                                                 str = ((IFormattable)arg).ToString (arg_format, provider);
 617                                         else
 618                                                 str = arg.ToString ();
 619
 620                                         // pad formatted string and append to result
 621
 622                                         if (width > str.length) {
 623                                                 string pad = new String (' ', width - str.length);
 624
 625                                                 if (left_align) {
 626                                                         result.Append (str);
 627                                                         result.Append (pad);
 628                                                 }
 629                                                 else {
 630                                                         result.Append (pad);
 631                                                         result.Append (str);
 632                                                 }
 633                                         }
 634                                         else
 635                                                 result.Append (str);
 636
 637                                         start = ptr;
 638                                 }
 639                                 else if (c == '}' && format[ptr] == '}') {
 640                                         result.Append (format, start, ptr - start - 1);
 641                                         start = ptr ++;
 642                                 }
 643                         }
 644
 645                         if (start < format.length)
 646                                 result.Append (format.Substring (start));
 647
 648                         return result.ToString ();
 649                 }
 650
 651                 public static String Copy (String str) {
 652                         if (str == null)
 653                                 throw new ArgumentNullException ();
 654
 655                         int length = str.length;
 656
 657                         String tmp = InternalAllocateStr(length);
 658                         InternalStrcpy(tmp, 0, str);
 659                         return tmp;
 660                 }
 661
 662                 public static String Concat(Object obj) {
 663                         if (null == obj)
 664                                 return String.Empty;
 665
 666                         return obj.ToString();
 667                 }
 668
 669                 public static String Concat(Object obj1, Object obj2) {
 670                         if (null == obj1)
 671                                 obj1 = String.Empty;
 672
 673                         if (null == obj2)
 674                                 obj2 = String.Empty;
 675
 676                         return Concat(obj1.ToString(), obj2.ToString());
 677                 }
 678
 679                 public static String Concat(Object obj1, Object obj2, Object obj3) {
 680                         if (null == obj1)
 681                                 obj1 = String.Empty;
 682
 683                         if (null == obj2)
 684                                 obj2 = String.Empty;
 685
 686                         if (null == obj3)
 687                                 obj3 = String.Empty;
 688
 689                         return Concat(obj1.ToString(), obj2.ToString(), obj3.ToString());
 690                 }
 691
 692                 //
 693                 // I can not find the "__arglist" argument on the spec
 694                 //
 695 #if !__MonoCS__
 696                 [CLSCompliant(false)]
 697                 public static String Concat (Object arg0, Object arg1, Object arg2, Object arg3, __arglist) {
 698                         throw new NotImplementedException();
 699                 }
 700 #endif
 701
 702                 public static String Concat(String s1, String s2) {
 703                         if (null == s1) {
 704                                 if (null == s2) { return String.Empty; }
 705                                 return s2;
 706                         }
 707
 708                         if (null == s2) { return s1; }
 709
 710                         String tmp = InternalAllocateStr(s1.length + s2.length);
 711
 712                         InternalStrcpy(tmp, 0, s1);
 713                         InternalStrcpy(tmp, s1.length, s2);
 714
 715                         return tmp;
 716                 }
 717
 718                 public static String Concat(String s1, String s2, String s3) {
 719                         if (null == s1 && null == s2 && null == s3) {
 720                                 return String.Empty;
 721                         }
 722
 723                         if (null == s1) { s1 = String.Empty; }
 724                         if (null == s2) { s2 = String.Empty; }
 725                         if (null == s3) { s3 = String.Empty; }
 726
 727                         String tmp = InternalAllocateStr(s1.length + s2.length + s3.length);
 728
 729                         InternalStrcpy(tmp, 0, s1);
 730                         InternalStrcpy(tmp, s1.length, s2);
 731                         InternalStrcpy(tmp, s1.length + s2.length, s3);
 732
 733                         return tmp;
 734                 }
 735
 736                 public static String Concat(String s1, String s2, String s3, String s4) {
 737                         if (null == s1 && null == s2 && null == s3 && null == s4) {
 738                                 return String.Empty;
 739                         }
 740
 741                         if (null == s1) { s1 = String.Empty; }
 742                         if (null == s2) { s2 = String.Empty; }
 743                         if (null == s3) { s3 = String.Empty; }
 744                         if (null == s4) { s4 = String.Empty; }
 745
 746                         String tmp = InternalAllocateStr(s1.length + s2.length + s3.length + s4.length);
 747
 748                         InternalStrcpy(tmp, 0, s1);
 749                         InternalStrcpy(tmp, s1.length, s2);
 750                         InternalStrcpy(tmp, s1.length + s2.length, s3);
 751                         InternalStrcpy(tmp, s1.length + s2.length + s3.length, s4);
 752
 753                         return tmp;
 754                 }
 755
 756                 public static String Concat(params Object[] args) {
 757                         string [] strings;
 758                         int len, i, currentpos;
 759
 760                         if (null == args)
 761                                 throw new ArgumentNullException ();
 762
 763                         strings = new string [args.Length];
 764                         len = 0;
 765                         i = 0;
 766                         foreach (object arg in args) {
 767                                 /* use Empty for each null argument */
 768                                 if (arg == null)
 769                                         strings[i] = String.Empty;
 770                                 else
 771                                         strings[i] = arg.ToString ();
 772                                 len += strings[i].length;
 773                                 i++;
 774                         }
 775
 776                         if (len == 0)
 777                                 return String.Empty;
 778
 779                         currentpos = 0;
 780
 781                         String tmp = InternalAllocateStr(len);
 782                         for (i = 0; i < strings.Length; i++) {
 783                                 InternalStrcpy(tmp, currentpos, strings[i]);
 784                                 currentpos += strings[i].length;
 785                         }
 786
 787                         return tmp;
 788                 }
 789
 790                 public static String Concat(params String[] values) {
 791                         int len, i, currentpos;
 792
 793                         if (values == null)
 794                                 throw new ArgumentNullException ();
 795
 796                         len = 0;
 797                         foreach (string value in values)
 798                                 len += value != null ? value.length : 0;
 799
 800                         if (len == 0)
 801                                 return String.Empty;
 802
 803                         currentpos = 0;
 804
 805                         String tmp = InternalAllocateStr(len);
 806                         for (i = 0; i < values.Length; i++) {
 807                                 if (values[i] == null)
 808                                         continue;
 809
 810                                 InternalStrcpy(tmp, currentpos, values[i]);
 811                                 currentpos += values[i].length;
 812                         }
 813
 814                         return tmp;
 815                 }
 816
 817                 public String Insert(int sindex, String value) {
 818                         if (null == value)
 819                                 throw new ArgumentNullException();
 820
 821                         if (sindex < 0 || sindex > this.length)
 822                                 throw new ArgumentOutOfRangeException();
 823
 824                         return InternalInsert(sindex, value);
 825                 }
 826
 827
 828                 public static string Intern (string str) {
 829                         if (null == str)
 830                                 throw new ArgumentNullException ();
 831
 832                         return InternalIntern(str);
 833                 }
 834
 835                 public static string IsInterned (string str) {
 836                         if (null == str)
 837                                 throw new ArgumentNullException();
 838
 839                         return InternalIsInterned(str);
 840                 }
 841
 842                 public static string Join (string separator, string [] value) {
 843                         if (value == null)
 844                                 throw new ArgumentNullException ();
 845
 846                         return Join(separator, value, 0, value.Length);
 847                 }
 848
 849                 public static string Join(string separator, string[] value, int sindex, int count) {
 850                         if (value == null)
 851                                 throw new ArgumentNullException ();
 852
 853                         if (sindex + count > value.Length)
 854                                 throw new ArgumentOutOfRangeException ();
 855
 856                         if (sindex == value.Length)
 857                                 return String.Empty;
 858
 859                         return InternalJoin(separator, value, sindex, count);
 860                 }
 861
 862                 bool IConvertible.ToBoolean (IFormatProvider provider) {
 863                         return Convert.ToBoolean (this);
 864                 }
 865
 866                 byte IConvertible.ToByte (IFormatProvider provider) {
 867                         return Convert.ToByte (this);
 868                 }
 869
 870                 char IConvertible.ToChar (IFormatProvider provider) {
 871                         return Convert.ToChar (this);
 872                 }
 873
 874                 DateTime IConvertible.ToDateTime (IFormatProvider provider) {
 875                         return Convert.ToDateTime (this);
 876                 }
 877
 878                 decimal IConvertible.ToDecimal (IFormatProvider provider) {
 879                         return Convert.ToDecimal (this);
 880                 }
 881
 882                 double IConvertible.ToDouble (IFormatProvider provider) {
 883                         return Convert.ToDouble (this);
 884                 }
 885
 886                 short IConvertible.ToInt16 (IFormatProvider provider) {
 887                         return Convert.ToInt16 (this);
 888                 }
 889
 890                 int IConvertible.ToInt32 (IFormatProvider provider) {
 891                         return Convert.ToInt32 (this);
 892                 }
 893
 894                 long IConvertible.ToInt64 (IFormatProvider provider) {
 895                         return Convert.ToInt64 (this);
 896                 }
 897
 898                 [CLSCompliant(false)]
 899                 sbyte IConvertible.ToSByte (IFormatProvider provider) {
 900                         return Convert.ToSByte (this);
 901                 }
 902
 903                 float IConvertible.ToSingle (IFormatProvider provider) {
 904                         return Convert.ToSingle (this);
 905                 }
 906                 string IConvertible.ToString (IFormatProvider format) {
 907                         return this;
 908                 }
 909
 910                 object IConvertible.ToType (Type conversionType, IFormatProvider provider) {
 911                         return Convert.ToType (this, conversionType,  provider);
 912                 }
 913
 914                 [CLSCompliant(false)]
 915                 ushort IConvertible.ToUInt16 (IFormatProvider provider) {
 916                         return Convert.ToUInt16 (this);
 917                 }
 918
 919                 [CLSCompliant(false)]
 920                 uint IConvertible.ToUInt32 (IFormatProvider provider) {
 921                         return Convert.ToUInt32 (this);
 922                 }
 923
 924                 [CLSCompliant(false)]
 925                 ulong IConvertible.ToUInt64 (IFormatProvider provider) {
 926                         return Convert.ToUInt64 (this);
 927                 }
 928
 929                 TypeCode IConvertible.GetTypeCode () {
 930                         return TypeCode.String;
 931                 }
 932
 933                 public int Length {
 934                         get {
 935                                 return length;
 936                         }
 937                 }
 938
 939                 public CharEnumerator GetEnumerator () {
 940                         return new CharEnumerator (this);
 941                 }
 942
 943                 IEnumerator IEnumerable.GetEnumerator () {
 944                         return new CharEnumerator (this);
 945                 }
 946
 947                 private static void ParseFormatSpecifier (string str, ref int ptr, out int n, out int width, out bool left_align, out string format) {
 948                         // parses format specifier of form:
 949                         //   N,[[-]M][:F]}
 950                         //
 951                         // where:
 952
 953                         try {
 954                                 // N = argument number (non-negative integer)
 955
 956                                 n = ParseDecimal (str, ref ptr);
 957                                 if (n < 0)
 958                                         throw new FormatException ("Input string was not in correct format.");
 959
 960                                 // M = width (non-negative integer)
 961
 962                                 if (str[ptr] == ',') {
 963                                         left_align = (str[++ ptr] == '-');
 964                                         if (left_align)
 965                                                 ++ ptr;
 966
 967                                         width = ParseDecimal (str, ref ptr);
 968                                         if (width < 0)
 969                                                 throw new FormatException ("Input string was not in correct format.");
 970                                 }
 971                                 else {
 972                                         width = 0;
 973                                         left_align = false;
 974                                 }
 975
 976                                 // F = argument format (string)
 977
 978                                 if (str[ptr] == ':') {
 979                                         int start = ++ ptr;
 980                                         while (str[ptr] != '}')
 981                                                 ++ ptr;
 982
 983                                         format = str.Substring (start, ptr - start);
 984                                 }
 985                                 else
 986                                         format = null;
 987
 988                                 if (str[ptr ++] != '}')
 989                                         throw new FormatException ("Input string was not in correct format.");
 990                         }
 991                         catch (IndexOutOfRangeException) {
 992                                 throw new FormatException ("Input string was not in correct format.");
 993                         }
 994                 }
 995
 996                 private static int ParseDecimal (string str, ref int ptr) {
 997                         int p = ptr;
 998                         int n = 0;
 999                         while (true) {
1000                                 char c = str[p];
1001                                 if (c < '0' || '9' < c)
1002                                         break;
1003
1004                                 n = n * 10 + c - '0';
1005                                 ++ p;
1006                         }
1007
1008                         if (p == ptr)
1009                                 return -1;
1010
1011                         ptr = p;
1012                         return n;
1013                 }
1014
1015                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1016                 private extern static string InternalJoin(string separator, string[] value, int sindex, int count);
1017
1018                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1019                 private extern String InternalInsert(int sindex, String value);
1020
1021                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1022                 private extern String InternalReplace(char oldChar, char newChar);
1023
1024                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1025                 private extern String InternalReplace(String oldValue, String newValue);
1026
1027                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1028                 private extern String InternalRemove(int sindex, int count);
1029
1030                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1031                 private extern void InternalCopyTo(int sindex, char[] dest, int dindex, int count);
1032
1033                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1034                 private extern String[] InternalSplit(char[] separator, int count);
1035
1036                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1037                 private extern String InternalTrim(char[] chars, int typ);
1038
1039                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1040                 private extern int InternalIndexOf(char value, int sindex, int count);
1041
1042                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1043                 private extern int InternalIndexOf(string value, int sindex, int count);
1044
1045                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1046                 private extern int InternalIndexOfAny(char [] arr, int sindex, int count);
1047
1048                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1049                 private extern int InternalLastIndexOf(char value, int sindex, int count);
1050
1051                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1052                 private extern int InternalLastIndexOf(String value, int sindex, int count);
1053
1054                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1055                 private extern int InternalLastIndexOfAny(char [] anyOf, int sindex, int count);
1056
1057                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1058                 private extern String InternalPad(int width, char chr, bool right);
1059
1060                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1061                 private extern String InternalToLower();
1062
1063                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1064                 private extern String InternalToUpper();
1065
1066                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1067                 private extern static String InternalAllocateStr(int length);
1068
1069                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1070                 private extern static void InternalStrcpy(String dest, int destPos, String src);
1071
1072                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1073                 private extern static void InternalStrcpy(String dest, int destPos, String src, int startPos, int count);
1074
1075                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1076                 private extern static string InternalIntern(string str);
1077
1078                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1079                 private extern static string InternalIsInterned(string str);
1080
1081                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1082                 private extern static int InternalCompare(String s1, int i1, String s2, int i2, int length, bool inCase);
1083
1084                 [MethodImplAttribute(MethodImplOptions.InternalCall)]
1085                 private extern static bool InternalEquals(String s1, String s2);
1086         }
1087 }