gcc/ada/a-strunb.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --                 A D A . S T R I N G S . U N B O U N D E D                --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2009, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  17 --                                                                          --
  18 -- As a special exception under Section 7 of GPL version 3, you are granted --
  19 -- additional permissions described in the GCC Runtime Library Exception,   --
  20 -- version 3.1, as published by the Free Software Foundation.               --
  21 --                                                                          --
  22 -- You should have received a copy of the GNU General Public License and    --
  23 -- a copy of the GCC Runtime Library Exception along with this program;     --
  24 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  25 -- <http://www.gnu.org/licenses/>.                                          --
  26 --                                                                          --
  27 -- GNAT was originally developed  by the GNAT team at  New York University. --
  28 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  29 --                                                                          --
  30 ------------------------------------------------------------------------------
  31
  32 with Ada.Strings.Fixed;
  33 with Ada.Strings.Search;
  34 with Ada.Unchecked_Deallocation;
  35
  36 package body Ada.Strings.Unbounded is
  37
  38    use Ada.Finalization;
  39
  40    ---------
  41    -- "&" --
  42    ---------
  43
  44    function "&"
  45      (Left  : Unbounded_String;
  46       Right : Unbounded_String) return Unbounded_String
  47    is
  48       L_Length : constant Natural := Left.Last;
  49       R_Length : constant Natural := Right.Last;
  50       Result   : Unbounded_String;
  51
  52    begin
  53       Result.Last := L_Length + R_Length;
  54
  55       Result.Reference := new String (1 .. Result.Last);
  56
  57       Result.Reference (1 .. L_Length) :=
  58         Left.Reference (1 .. Left.Last);
  59       Result.Reference (L_Length + 1 .. Result.Last) :=
  60         Right.Reference (1 .. Right.Last);
  61
  62       return Result;
  63    end "&";
  64
  65    function "&"
  66      (Left  : Unbounded_String;
  67       Right : String) return Unbounded_String
  68    is
  69       L_Length : constant Natural := Left.Last;
  70       Result   : Unbounded_String;
  71
  72    begin
  73       Result.Last := L_Length + Right'Length;
  74
  75       Result.Reference := new String (1 .. Result.Last);
  76
  77       Result.Reference (1 .. L_Length) := Left.Reference (1 .. Left.Last);
  78       Result.Reference (L_Length + 1 .. Result.Last) := Right;
  79
  80       return Result;
  81    end "&";
  82
  83    function "&"
  84      (Left  : String;
  85       Right : Unbounded_String) return Unbounded_String
  86    is
  87       R_Length : constant Natural := Right.Last;
  88       Result   : Unbounded_String;
  89
  90    begin
  91       Result.Last := Left'Length + R_Length;
  92
  93       Result.Reference := new String (1 .. Result.Last);
  94
  95       Result.Reference (1 .. Left'Length) := Left;
  96       Result.Reference (Left'Length + 1 .. Result.Last) :=
  97         Right.Reference (1 .. Right.Last);
  98
  99       return Result;
 100    end "&";
 101
 102    function "&"
 103      (Left  : Unbounded_String;
 104       Right : Character) return Unbounded_String
 105    is
 106       Result : Unbounded_String;
 107
 108    begin
 109       Result.Last := Left.Last + 1;
 110
 111       Result.Reference := new String (1 .. Result.Last);
 112
 113       Result.Reference (1 .. Result.Last - 1) :=
 114         Left.Reference (1 .. Left.Last);
 115       Result.Reference (Result.Last) := Right;
 116
 117       return Result;
 118    end "&";
 119
 120    function "&"
 121      (Left  : Character;
 122       Right : Unbounded_String) return Unbounded_String
 123    is
 124       Result : Unbounded_String;
 125
 126    begin
 127       Result.Last := Right.Last + 1;
 128
 129       Result.Reference := new String (1 .. Result.Last);
 130       Result.Reference (1) := Left;
 131       Result.Reference (2 .. Result.Last) :=
 132         Right.Reference (1 .. Right.Last);
 133       return Result;
 134    end "&";
 135
 136    ---------
 137    -- "*" --
 138    ---------
 139
 140    function "*"
 141      (Left  : Natural;
 142       Right : Character) return Unbounded_String
 143    is
 144       Result : Unbounded_String;
 145
 146    begin
 147       Result.Last   := Left;
 148
 149       Result.Reference := new String (1 .. Left);
 150       for J in Result.Reference'Range loop
 151          Result.Reference (J) := Right;
 152       end loop;
 153
 154       return Result;
 155    end "*";
 156
 157    function "*"
 158      (Left  : Natural;
 159       Right : String) return Unbounded_String
 160    is
 161       Len    : constant Natural := Right'Length;
 162       K      : Positive;
 163       Result : Unbounded_String;
 164
 165    begin
 166       Result.Last := Left * Len;
 167
 168       Result.Reference := new String (1 .. Result.Last);
 169
 170       K := 1;
 171       for J in 1 .. Left loop
 172          Result.Reference (K .. K + Len - 1) := Right;
 173          K := K + Len;
 174       end loop;
 175
 176       return Result;
 177    end "*";
 178
 179    function "*"
 180      (Left  : Natural;
 181       Right : Unbounded_String) return Unbounded_String
 182    is
 183       Len    : constant Natural := Right.Last;
 184       K      : Positive;
 185       Result : Unbounded_String;
 186
 187    begin
 188       Result.Last := Left * Len;
 189
 190       Result.Reference := new String (1 .. Result.Last);
 191
 192       K := 1;
 193       for J in 1 .. Left loop
 194          Result.Reference (K .. K + Len - 1) :=
 195            Right.Reference (1 .. Right.Last);
 196          K := K + Len;
 197       end loop;
 198
 199       return Result;
 200    end "*";
 201
 202    ---------
 203    -- "<" --
 204    ---------
 205
 206    function "<"
 207      (Left  : Unbounded_String;
 208       Right : Unbounded_String) return Boolean
 209    is
 210    begin
 211       return
 212         Left.Reference (1 .. Left.Last) < Right.Reference (1 .. Right.Last);
 213    end "<";
 214
 215    function "<"
 216      (Left  : Unbounded_String;
 217       Right : String) return Boolean
 218    is
 219    begin
 220       return Left.Reference (1 .. Left.Last) < Right;
 221    end "<";
 222
 223    function "<"
 224      (Left  : String;
 225       Right : Unbounded_String) return Boolean
 226    is
 227    begin
 228       return Left < Right.Reference (1 .. Right.Last);
 229    end "<";
 230
 231    ----------
 232    -- "<=" --
 233    ----------
 234
 235    function "<="
 236      (Left  : Unbounded_String;
 237       Right : Unbounded_String) return Boolean
 238    is
 239    begin
 240       return
 241         Left.Reference (1 .. Left.Last) <= Right.Reference (1 .. Right.Last);
 242    end "<=";
 243
 244    function "<="
 245      (Left  : Unbounded_String;
 246       Right : String) return Boolean
 247    is
 248    begin
 249       return Left.Reference (1 .. Left.Last) <= Right;
 250    end "<=";
 251
 252    function "<="
 253      (Left  : String;
 254       Right : Unbounded_String) return Boolean
 255    is
 256    begin
 257       return Left <= Right.Reference (1 .. Right.Last);
 258    end "<=";
 259
 260    ---------
 261    -- "=" --
 262    ---------
 263
 264    function "="
 265      (Left  : Unbounded_String;
 266       Right : Unbounded_String) return Boolean
 267    is
 268    begin
 269       return
 270         Left.Reference (1 .. Left.Last) = Right.Reference (1 .. Right.Last);
 271    end "=";
 272
 273    function "="
 274      (Left  : Unbounded_String;
 275       Right : String) return Boolean
 276    is
 277    begin
 278       return Left.Reference (1 .. Left.Last) = Right;
 279    end "=";
 280
 281    function "="
 282      (Left  : String;
 283       Right : Unbounded_String) return Boolean
 284    is
 285    begin
 286       return Left = Right.Reference (1 .. Right.Last);
 287    end "=";
 288
 289    ---------
 290    -- ">" --
 291    ---------
 292
 293    function ">"
 294      (Left  : Unbounded_String;
 295       Right : Unbounded_String) return Boolean
 296    is
 297    begin
 298       return
 299         Left.Reference (1 .. Left.Last) > Right.Reference (1 .. Right.Last);
 300    end ">";
 301
 302    function ">"
 303      (Left  : Unbounded_String;
 304       Right : String) return Boolean
 305    is
 306    begin
 307       return Left.Reference (1 .. Left.Last) > Right;
 308    end ">";
 309
 310    function ">"
 311      (Left  : String;
 312       Right : Unbounded_String) return Boolean
 313    is
 314    begin
 315       return Left > Right.Reference (1 .. Right.Last);
 316    end ">";
 317
 318    ----------
 319    -- ">=" --
 320    ----------
 321
 322    function ">="
 323      (Left  : Unbounded_String;
 324       Right : Unbounded_String) return Boolean
 325    is
 326    begin
 327       return
 328         Left.Reference (1 .. Left.Last) >= Right.Reference (1 .. Right.Last);
 329    end ">=";
 330
 331    function ">="
 332      (Left  : Unbounded_String;
 333       Right : String) return Boolean
 334    is
 335    begin
 336       return Left.Reference (1 .. Left.Last) >= Right;
 337    end ">=";
 338
 339    function ">="
 340      (Left  : String;
 341       Right : Unbounded_String) return Boolean
 342    is
 343    begin
 344       return Left >= Right.Reference (1 .. Right.Last);
 345    end ">=";
 346
 347    ------------
 348    -- Adjust --
 349    ------------
 350
 351    procedure Adjust (Object : in out Unbounded_String) is
 352    begin
 353       --  Copy string, except we do not copy the statically allocated null
 354       --  string since it can never be deallocated. Note that we do not copy
 355       --  extra string room here to avoid dragging unused allocated memory.
 356
 357       if Object.Reference /= Null_String'Access then
 358          Object.Reference := new String'(Object.Reference (1 .. Object.Last));
 359       end if;
 360    end Adjust;
 361
 362    ------------
 363    -- Append --
 364    ------------
 365
 366    procedure Append
 367      (Source   : in out Unbounded_String;
 368       New_Item : Unbounded_String)
 369    is
 370    begin
 371       Realloc_For_Chunk (Source, New_Item.Last);
 372       Source.Reference (Source.Last + 1 .. Source.Last + New_Item.Last) :=
 373         New_Item.Reference (1 .. New_Item.Last);
 374       Source.Last := Source.Last + New_Item.Last;
 375    end Append;
 376
 377    procedure Append
 378      (Source   : in out Unbounded_String;
 379       New_Item : String)
 380    is
 381    begin
 382       Realloc_For_Chunk (Source, New_Item'Length);
 383       Source.Reference (Source.Last + 1 .. Source.Last + New_Item'Length) :=
 384         New_Item;
 385       Source.Last := Source.Last + New_Item'Length;
 386    end Append;
 387
 388    procedure Append
 389      (Source   : in out Unbounded_String;
 390       New_Item : Character)
 391    is
 392    begin
 393       Realloc_For_Chunk (Source, 1);
 394       Source.Reference (Source.Last + 1) := New_Item;
 395       Source.Last := Source.Last + 1;
 396    end Append;
 397
 398    -----------
 399    -- Count --
 400    -----------
 401
 402    function Count
 403      (Source  : Unbounded_String;
 404       Pattern : String;
 405       Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
 406    is
 407    begin
 408       return
 409         Search.Count (Source.Reference (1 .. Source.Last), Pattern, Mapping);
 410    end Count;
 411
 412    function Count
 413      (Source  : Unbounded_String;
 414       Pattern : String;
 415       Mapping : Maps.Character_Mapping_Function) return Natural
 416    is
 417    begin
 418       return
 419         Search.Count (Source.Reference (1 .. Source.Last), Pattern, Mapping);
 420    end Count;
 421
 422    function Count
 423      (Source : Unbounded_String;
 424       Set    : Maps.Character_Set) return Natural
 425    is
 426    begin
 427       return Search.Count (Source.Reference (1 .. Source.Last), Set);
 428    end Count;
 429
 430    ------------
 431    -- Delete --
 432    ------------
 433
 434    function Delete
 435      (Source  : Unbounded_String;
 436       From    : Positive;
 437       Through : Natural) return Unbounded_String
 438    is
 439    begin
 440       return
 441         To_Unbounded_String
 442           (Fixed.Delete (Source.Reference (1 .. Source.Last), From, Through));
 443    end Delete;
 444
 445    procedure Delete
 446      (Source  : in out Unbounded_String;
 447       From    : Positive;
 448       Through : Natural)
 449    is
 450    begin
 451       if From > Through then
 452          null;
 453
 454       elsif From < Source.Reference'First or else Through > Source.Last then
 455          raise Index_Error;
 456
 457       else
 458          declare
 459             Len : constant Natural := Through - From + 1;
 460
 461          begin
 462             Source.Reference (From .. Source.Last - Len) :=
 463               Source.Reference (Through + 1 .. Source.Last);
 464             Source.Last := Source.Last - Len;
 465          end;
 466       end if;
 467    end Delete;
 468
 469    -------------
 470    -- Element --
 471    -------------
 472
 473    function Element
 474      (Source : Unbounded_String;
 475       Index  : Positive) return Character
 476    is
 477    begin
 478       if Index <= Source.Last then
 479          return Source.Reference (Index);
 480       else
 481          raise Strings.Index_Error;
 482       end if;
 483    end Element;
 484
 485    --------------
 486    -- Finalize --
 487    --------------
 488
 489    procedure Finalize (Object : in out Unbounded_String) is
 490       procedure Deallocate is
 491          new Ada.Unchecked_Deallocation (String, String_Access);
 492
 493    begin
 494       --  Note: Don't try to free statically allocated null string
 495
 496       if Object.Reference /= Null_String'Access then
 497          Deallocate (Object.Reference);
 498          Object.Reference := Null_Unbounded_String.Reference;
 499          Object.Last := 0;
 500       end if;
 501    end Finalize;
 502
 503    ----------------
 504    -- Find_Token --
 505    ----------------
 506
 507    procedure Find_Token
 508      (Source : Unbounded_String;
 509       Set    : Maps.Character_Set;
 510       Test   : Strings.Membership;
 511       First  : out Positive;
 512       Last   : out Natural)
 513    is
 514    begin
 515       Search.Find_Token
 516         (Source.Reference (1 .. Source.Last), Set, Test, First, Last);
 517    end Find_Token;
 518
 519    ----------
 520    -- Free --
 521    ----------
 522
 523    procedure Free (X : in out String_Access) is
 524       procedure Deallocate is
 525          new Ada.Unchecked_Deallocation (String, String_Access);
 526
 527    begin
 528       --  Note: Do not try to free statically allocated null string
 529
 530       if X /= Null_Unbounded_String.Reference then
 531          Deallocate (X);
 532       end if;
 533    end Free;
 534
 535    ----------
 536    -- Head --
 537    ----------
 538
 539    function Head
 540      (Source : Unbounded_String;
 541       Count  : Natural;
 542       Pad    : Character := Space) return Unbounded_String
 543    is
 544    begin
 545       return To_Unbounded_String
 546         (Fixed.Head (Source.Reference (1 .. Source.Last), Count, Pad));
 547    end Head;
 548
 549    procedure Head
 550      (Source : in out Unbounded_String;
 551       Count  : Natural;
 552       Pad    : Character := Space)
 553    is
 554       Old : String_Access := Source.Reference;
 555    begin
 556       Source.Reference :=
 557         new String'(Fixed.Head (Source.Reference (1 .. Source.Last),
 558                     Count, Pad));
 559       Source.Last := Source.Reference'Length;
 560       Free (Old);
 561    end Head;
 562
 563    -----------
 564    -- Index --
 565    -----------
 566
 567    function Index
 568      (Source  : Unbounded_String;
 569       Pattern : String;
 570       Going   : Strings.Direction := Strings.Forward;
 571       Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
 572    is
 573    begin
 574       return Search.Index
 575         (Source.Reference (1 .. Source.Last), Pattern, Going, Mapping);
 576    end Index;
 577
 578    function Index
 579      (Source  : Unbounded_String;
 580       Pattern : String;
 581       Going   : Direction := Forward;
 582       Mapping : Maps.Character_Mapping_Function) return Natural
 583    is
 584    begin
 585       return Search.Index
 586         (Source.Reference (1 .. Source.Last), Pattern, Going, Mapping);
 587    end Index;
 588
 589    function Index
 590      (Source : Unbounded_String;
 591       Set    : Maps.Character_Set;
 592       Test   : Strings.Membership := Strings.Inside;
 593       Going  : Strings.Direction  := Strings.Forward) return Natural
 594    is
 595    begin
 596       return Search.Index
 597         (Source.Reference (1 .. Source.Last), Set, Test, Going);
 598    end Index;
 599
 600    function Index
 601      (Source  : Unbounded_String;
 602       Pattern : String;
 603       From    : Positive;
 604       Going   : Direction := Forward;
 605       Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
 606    is
 607    begin
 608       return Search.Index
 609         (Source.Reference (1 .. Source.Last), Pattern, From, Going, Mapping);
 610    end Index;
 611
 612    function Index
 613      (Source  : Unbounded_String;
 614       Pattern : String;
 615       From    : Positive;
 616       Going   : Direction := Forward;
 617       Mapping : Maps.Character_Mapping_Function) return Natural
 618    is
 619    begin
 620       return Search.Index
 621         (Source.Reference (1 .. Source.Last), Pattern, From, Going, Mapping);
 622    end Index;
 623
 624    function Index
 625      (Source  : Unbounded_String;
 626       Set     : Maps.Character_Set;
 627       From    : Positive;
 628       Test    : Membership := Inside;
 629       Going   : Direction := Forward) return Natural
 630    is
 631    begin
 632       return Search.Index
 633         (Source.Reference (1 .. Source.Last), Set, From, Test, Going);
 634    end Index;
 635
 636    function Index_Non_Blank
 637      (Source : Unbounded_String;
 638       Going  : Strings.Direction := Strings.Forward) return Natural
 639    is
 640    begin
 641       return
 642         Search.Index_Non_Blank
 643           (Source.Reference (1 .. Source.Last), Going);
 644    end Index_Non_Blank;
 645
 646    function Index_Non_Blank
 647      (Source : Unbounded_String;
 648       From   : Positive;
 649       Going  : Direction := Forward) return Natural
 650    is
 651    begin
 652       return
 653         Search.Index_Non_Blank
 654           (Source.Reference (1 .. Source.Last), From, Going);
 655    end Index_Non_Blank;
 656
 657    ----------------
 658    -- Initialize --
 659    ----------------
 660
 661    procedure Initialize (Object : in out Unbounded_String) is
 662    begin
 663       Object.Reference := Null_Unbounded_String.Reference;
 664       Object.Last      := 0;
 665    end Initialize;
 666
 667    ------------
 668    -- Insert --
 669    ------------
 670
 671    function Insert
 672      (Source   : Unbounded_String;
 673       Before   : Positive;
 674       New_Item : String) return Unbounded_String
 675    is
 676    begin
 677       return To_Unbounded_String
 678         (Fixed.Insert (Source.Reference (1 .. Source.Last), Before, New_Item));
 679    end Insert;
 680
 681    procedure Insert
 682      (Source   : in out Unbounded_String;
 683       Before   : Positive;
 684       New_Item : String)
 685    is
 686    begin
 687       if Before not in Source.Reference'First .. Source.Last + 1 then
 688          raise Index_Error;
 689       end if;
 690
 691       Realloc_For_Chunk (Source, New_Item'Length);
 692
 693       Source.Reference
 694         (Before +  New_Item'Length .. Source.Last + New_Item'Length) :=
 695            Source.Reference (Before .. Source.Last);
 696
 697       Source.Reference (Before .. Before + New_Item'Length - 1) := New_Item;
 698       Source.Last := Source.Last + New_Item'Length;
 699    end Insert;
 700
 701    ------------
 702    -- Length --
 703    ------------
 704
 705    function Length (Source : Unbounded_String) return Natural is
 706    begin
 707       return Source.Last;
 708    end Length;
 709
 710    ---------------
 711    -- Overwrite --
 712    ---------------
 713
 714    function Overwrite
 715      (Source   : Unbounded_String;
 716       Position : Positive;
 717       New_Item : String) return Unbounded_String
 718    is
 719    begin
 720       return To_Unbounded_String
 721         (Fixed.Overwrite
 722           (Source.Reference (1 .. Source.Last), Position, New_Item));
 723    end Overwrite;
 724
 725    procedure Overwrite
 726      (Source    : in out Unbounded_String;
 727       Position  : Positive;
 728       New_Item  : String)
 729    is
 730       NL : constant Natural := New_Item'Length;
 731    begin
 732       if Position <= Source.Last - NL + 1 then
 733          Source.Reference (Position .. Position + NL - 1) := New_Item;
 734       else
 735          declare
 736             Old : String_Access := Source.Reference;
 737          begin
 738             Source.Reference := new String'
 739               (Fixed.Overwrite
 740                 (Source.Reference (1 .. Source.Last), Position, New_Item));
 741             Source.Last := Source.Reference'Length;
 742             Free (Old);
 743          end;
 744       end if;
 745    end Overwrite;
 746
 747    -----------------------
 748    -- Realloc_For_Chunk --
 749    -----------------------
 750
 751    procedure Realloc_For_Chunk
 752      (Source     : in out Unbounded_String;
 753       Chunk_Size : Natural)
 754    is
 755       Growth_Factor : constant := 32;
 756       --  The growth factor controls how much extra space is allocated when
 757       --  we have to increase the size of an allocated unbounded string. By
 758       --  allocating extra space, we avoid the need to reallocate on every
 759       --  append, particularly important when a string is built up by repeated
 760       --  append operations of small pieces. This is expressed as a factor so
 761       --  32 means add 1/32 of the length of the string as growth space.
 762
 763       Min_Mul_Alloc : constant := Standard'Maximum_Alignment;
 764       --  Allocation will be done by a multiple of Min_Mul_Alloc This causes
 765       --  no memory loss as most (all?) malloc implementations are obliged to
 766       --  align the returned memory on the maximum alignment as malloc does not
 767       --  know the target alignment.
 768
 769       S_Length : constant Natural := Source.Reference'Length;
 770
 771    begin
 772       if Chunk_Size > S_Length - Source.Last then
 773          declare
 774             New_Size : constant Positive :=
 775                          S_Length + Chunk_Size + (S_Length / Growth_Factor);
 776
 777             New_Rounded_Up_Size : constant Positive :=
 778                                     ((New_Size - 1) / Min_Mul_Alloc + 1) *
 779                                        Min_Mul_Alloc;
 780
 781             Tmp : constant String_Access :=
 782                     new String (1 .. New_Rounded_Up_Size);
 783
 784          begin
 785             Tmp (1 .. Source.Last) := Source.Reference (1 .. Source.Last);
 786             Free (Source.Reference);
 787             Source.Reference := Tmp;
 788          end;
 789       end if;
 790    end Realloc_For_Chunk;
 791
 792    ---------------------
 793    -- Replace_Element --
 794    ---------------------
 795
 796    procedure Replace_Element
 797      (Source : in out Unbounded_String;
 798       Index  : Positive;
 799       By     : Character)
 800    is
 801    begin
 802       if Index <= Source.Last then
 803          Source.Reference (Index) := By;
 804       else
 805          raise Strings.Index_Error;
 806       end if;
 807    end Replace_Element;
 808
 809    -------------------
 810    -- Replace_Slice --
 811    -------------------
 812
 813    function Replace_Slice
 814      (Source : Unbounded_String;
 815       Low    : Positive;
 816       High   : Natural;
 817       By     : String) return Unbounded_String
 818    is
 819    begin
 820       return To_Unbounded_String
 821         (Fixed.Replace_Slice
 822            (Source.Reference (1 .. Source.Last), Low, High, By));
 823    end Replace_Slice;
 824
 825    procedure Replace_Slice
 826      (Source : in out Unbounded_String;
 827       Low    : Positive;
 828       High   : Natural;
 829       By     : String)
 830    is
 831       Old : String_Access := Source.Reference;
 832    begin
 833       Source.Reference := new String'
 834         (Fixed.Replace_Slice
 835            (Source.Reference (1 .. Source.Last), Low, High, By));
 836       Source.Last := Source.Reference'Length;
 837       Free (Old);
 838    end Replace_Slice;
 839
 840    --------------------------
 841    -- Set_Unbounded_String --
 842    --------------------------
 843
 844    procedure Set_Unbounded_String
 845      (Target : out Unbounded_String;
 846       Source : String)
 847    is
 848       Old : String_Access := Target.Reference;
 849    begin
 850       Target.Last          := Source'Length;
 851       Target.Reference     := new String (1 .. Source'Length);
 852       Target.Reference.all := Source;
 853       Free (Old);
 854    end Set_Unbounded_String;
 855
 856    -----------
 857    -- Slice --
 858    -----------
 859
 860    function Slice
 861      (Source : Unbounded_String;
 862       Low    : Positive;
 863       High   : Natural) return String
 864    is
 865    begin
 866       --  Note: test of High > Length is in accordance with AI95-00128
 867
 868       if Low > Source.Last + 1 or else High > Source.Last then
 869          raise Index_Error;
 870       else
 871          return Source.Reference (Low .. High);
 872       end if;
 873    end Slice;
 874
 875    ----------
 876    -- Tail --
 877    ----------
 878
 879    function Tail
 880      (Source : Unbounded_String;
 881       Count  : Natural;
 882       Pad    : Character := Space) return Unbounded_String is
 883    begin
 884       return To_Unbounded_String
 885         (Fixed.Tail (Source.Reference (1 .. Source.Last), Count, Pad));
 886    end Tail;
 887
 888    procedure Tail
 889      (Source : in out Unbounded_String;
 890       Count  : Natural;
 891       Pad    : Character := Space)
 892    is
 893       Old : String_Access := Source.Reference;
 894    begin
 895       Source.Reference := new String'
 896         (Fixed.Tail (Source.Reference (1 .. Source.Last), Count, Pad));
 897       Source.Last := Source.Reference'Length;
 898       Free (Old);
 899    end Tail;
 900
 901    ---------------
 902    -- To_String --
 903    ---------------
 904
 905    function To_String (Source : Unbounded_String) return String is
 906    begin
 907       return Source.Reference (1 .. Source.Last);
 908    end To_String;
 909
 910    -------------------------
 911    -- To_Unbounded_String --
 912    -------------------------
 913
 914    function To_Unbounded_String (Source : String) return Unbounded_String is
 915       Result : Unbounded_String;
 916    begin
 917       Result.Last          := Source'Length;
 918       Result.Reference     := new String (1 .. Source'Length);
 919       Result.Reference.all := Source;
 920       return Result;
 921    end To_Unbounded_String;
 922
 923    function To_Unbounded_String
 924      (Length : Natural) return Unbounded_String
 925    is
 926       Result : Unbounded_String;
 927    begin
 928       Result.Last      := Length;
 929       Result.Reference := new String (1 .. Length);
 930       return Result;
 931    end To_Unbounded_String;
 932
 933    ---------------
 934    -- Translate --
 935    ---------------
 936
 937    function Translate
 938      (Source  : Unbounded_String;
 939       Mapping : Maps.Character_Mapping) return Unbounded_String
 940    is
 941    begin
 942       return To_Unbounded_String
 943         (Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping));
 944    end Translate;
 945
 946    procedure Translate
 947      (Source  : in out Unbounded_String;
 948       Mapping : Maps.Character_Mapping)
 949    is
 950    begin
 951       Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping);
 952    end Translate;
 953
 954    function Translate
 955      (Source  : Unbounded_String;
 956       Mapping : Maps.Character_Mapping_Function) return Unbounded_String
 957    is
 958    begin
 959       return To_Unbounded_String
 960         (Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping));
 961    end Translate;
 962
 963    procedure Translate
 964      (Source  : in out Unbounded_String;
 965       Mapping : Maps.Character_Mapping_Function)
 966    is
 967    begin
 968       Fixed.Translate (Source.Reference (1 .. Source.Last), Mapping);
 969    end Translate;
 970
 971    ----------
 972    -- Trim --
 973    ----------
 974
 975    function Trim
 976      (Source : Unbounded_String;
 977       Side   : Trim_End) return Unbounded_String
 978    is
 979    begin
 980       return To_Unbounded_String
 981         (Fixed.Trim (Source.Reference (1 .. Source.Last), Side));
 982    end Trim;
 983
 984    procedure Trim
 985      (Source : in out Unbounded_String;
 986       Side   : Trim_End)
 987    is
 988       Old : String_Access := Source.Reference;
 989    begin
 990       Source.Reference := new String'
 991         (Fixed.Trim (Source.Reference (1 .. Source.Last), Side));
 992       Source.Last      := Source.Reference'Length;
 993       Free (Old);
 994    end Trim;
 995
 996    function Trim
 997      (Source : Unbounded_String;
 998       Left   : Maps.Character_Set;
 999       Right  : Maps.Character_Set) return Unbounded_String
1000    is
1001    begin
1002       return To_Unbounded_String
1003         (Fixed.Trim (Source.Reference (1 .. Source.Last), Left, Right));
1004    end Trim;
1005
1006    procedure Trim
1007      (Source : in out Unbounded_String;
1008       Left   : Maps.Character_Set;
1009       Right  : Maps.Character_Set)
1010    is
1011       Old : String_Access := Source.Reference;
1012    begin
1013       Source.Reference := new String'
1014         (Fixed.Trim (Source.Reference (1 .. Source.Last), Left, Right));
1015       Source.Last      := Source.Reference'Length;
1016       Free (Old);
1017    end Trim;
1018
1019    ---------------------
1020    -- Unbounded_Slice --
1021    ---------------------
1022
1023    function Unbounded_Slice
1024      (Source : Unbounded_String;
1025       Low    : Positive;
1026       High   : Natural) return Unbounded_String
1027    is
1028    begin
1029       if Low > Source.Last + 1 or else High > Source.Last then
1030          raise Index_Error;
1031       else
1032          return To_Unbounded_String (Source.Reference.all (Low .. High));
1033       end if;
1034    end Unbounded_Slice;
1035
1036    procedure Unbounded_Slice
1037      (Source : Unbounded_String;
1038       Target : out Unbounded_String;
1039       Low    : Positive;
1040       High   : Natural)
1041    is
1042    begin
1043       if Low > Source.Last + 1 or else High > Source.Last then
1044          raise Index_Error;
1045       else
1046          Target := To_Unbounded_String (Source.Reference.all (Low .. High));
1047       end if;
1048    end Unbounded_Slice;
1049
1050 end Ada.Strings.Unbounded;