gcc/ada/a-stwise.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT RUN-TIME COMPONENTS                         --
   4 --                                                                          --
   5 --              A D A . S T R I N G S . W I D E _ S E A R C H               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2010, 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.Wide_Maps; use Ada.Strings.Wide_Maps;
  33 with System;                use System;
  34
  35 package body Ada.Strings.Wide_Search is
  36
  37    -----------------------
  38    -- Local Subprograms --
  39    -----------------------
  40
  41    function Belongs
  42      (Element : Wide_Character;
  43       Set     : Wide_Maps.Wide_Character_Set;
  44       Test    : Membership) return Boolean;
  45    pragma Inline (Belongs);
  46    --  Determines if the given element is in (Test = Inside) or not in
  47    --  (Test = Outside) the given character set.
  48
  49    -------------
  50    -- Belongs --
  51    -------------
  52
  53    function Belongs
  54      (Element : Wide_Character;
  55       Set     : Wide_Maps.Wide_Character_Set;
  56       Test    : Membership) return Boolean
  57    is
  58    begin
  59       if Test = Inside then
  60          return Is_In (Element, Set);
  61       else
  62          return not Is_In (Element, Set);
  63       end if;
  64    end Belongs;
  65
  66    -----------
  67    -- Count --
  68    -----------
  69
  70    function Count
  71      (Source  : Wide_String;
  72       Pattern : Wide_String;
  73       Mapping : Wide_Maps.Wide_Character_Mapping := Wide_Maps.Identity)
  74       return Natural
  75    is
  76       PL1 : constant Integer := Pattern'Length - 1;
  77       Num : Natural;
  78       Ind : Natural;
  79       Cur : Natural;
  80
  81    begin
  82       if Pattern = "" then
  83          raise Pattern_Error;
  84       end if;
  85
  86       Num := 0;
  87       Ind := Source'First;
  88
  89       --  Unmapped case
  90
  91       if Mapping'Address = Wide_Maps.Identity'Address then
  92          while Ind <= Source'Last - PL1 loop
  93             if Pattern = Source (Ind .. Ind + PL1) then
  94                Num := Num + 1;
  95                Ind := Ind + Pattern'Length;
  96             else
  97                Ind := Ind + 1;
  98             end if;
  99          end loop;
 100
 101       --  Mapped case
 102
 103       else
 104          while Ind <= Source'Last - PL1 loop
 105             Cur := Ind;
 106             for K in Pattern'Range loop
 107                if Pattern (K) /= Value (Mapping, Source (Cur)) then
 108                   Ind := Ind + 1;
 109                   goto Cont;
 110                else
 111                   Cur := Cur + 1;
 112                end if;
 113             end loop;
 114
 115             Num := Num + 1;
 116             Ind := Ind + Pattern'Length;
 117
 118          <<Cont>>
 119             null;
 120          end loop;
 121       end if;
 122
 123       --  Return result
 124
 125       return Num;
 126    end Count;
 127
 128    function Count
 129      (Source  : Wide_String;
 130       Pattern : Wide_String;
 131       Mapping : Wide_Maps.Wide_Character_Mapping_Function) return Natural
 132    is
 133       PL1 : constant Integer := Pattern'Length - 1;
 134       Num : Natural;
 135       Ind : Natural;
 136       Cur : Natural;
 137
 138    begin
 139       if Pattern = "" then
 140          raise Pattern_Error;
 141       end if;
 142
 143       --  Check for null pointer in case checks are off
 144
 145       if Mapping = null then
 146          raise Constraint_Error;
 147       end if;
 148
 149       Num := 0;
 150       Ind := Source'First;
 151       while Ind <= Source'Last - PL1 loop
 152          Cur := Ind;
 153          for K in Pattern'Range loop
 154             if Pattern (K) /= Mapping (Source (Cur)) then
 155                Ind := Ind + 1;
 156                goto Cont;
 157             else
 158                Cur := Cur + 1;
 159             end if;
 160          end loop;
 161
 162          Num := Num + 1;
 163          Ind := Ind + Pattern'Length;
 164
 165       <<Cont>>
 166          null;
 167       end loop;
 168
 169       return Num;
 170    end Count;
 171
 172    function Count
 173      (Source : Wide_String;
 174       Set    : Wide_Maps.Wide_Character_Set) return Natural
 175    is
 176       N : Natural := 0;
 177
 178    begin
 179       for J in Source'Range loop
 180          if Is_In (Source (J), Set) then
 181             N := N + 1;
 182          end if;
 183       end loop;
 184
 185       return N;
 186    end Count;
 187
 188    ----------------
 189    -- Find_Token --
 190    ----------------
 191
 192    procedure Find_Token
 193      (Source : Wide_String;
 194       Set    : Wide_Maps.Wide_Character_Set;
 195       From   : Positive;
 196       Test   : Membership;
 197       First  : out Positive;
 198       Last   : out Natural)
 199    is
 200    begin
 201       for J in From .. Source'Last loop
 202          if Belongs (Source (J), Set, Test) then
 203             First := J;
 204
 205             for K in J + 1 .. Source'Last loop
 206                if not Belongs (Source (K), Set, Test) then
 207                   Last := K - 1;
 208                   return;
 209                end if;
 210             end loop;
 211
 212             --  Here if J indexes first char of token, and all chars after J
 213             --  are in the token.
 214
 215             Last := Source'Last;
 216             return;
 217          end if;
 218       end loop;
 219
 220       --  Here if no token found
 221
 222       First := From;
 223       Last  := 0;
 224    end Find_Token;
 225
 226    procedure Find_Token
 227      (Source : Wide_String;
 228       Set    : Wide_Maps.Wide_Character_Set;
 229       Test   : Membership;
 230       First  : out Positive;
 231       Last   : out Natural)
 232    is
 233    begin
 234       for J in Source'Range loop
 235          if Belongs (Source (J), Set, Test) then
 236             First := J;
 237
 238             for K in J + 1 .. Source'Last loop
 239                if not Belongs (Source (K), Set, Test) then
 240                   Last := K - 1;
 241                   return;
 242                end if;
 243             end loop;
 244
 245             --  Here if J indexes first char of token, and all chars after J
 246             --  are in the token.
 247
 248             Last := Source'Last;
 249             return;
 250          end if;
 251       end loop;
 252
 253       --  Here if no token found
 254
 255       First := Source'First;
 256       Last  := 0;
 257    end Find_Token;
 258
 259    -----------
 260    -- Index --
 261    -----------
 262
 263    function Index
 264      (Source  : Wide_String;
 265       Pattern : Wide_String;
 266       Going   : Direction := Forward;
 267       Mapping : Wide_Maps.Wide_Character_Mapping := Wide_Maps.Identity)
 268       return Natural
 269    is
 270       PL1 : constant Integer := Pattern'Length - 1;
 271       Cur : Natural;
 272
 273       Ind : Integer;
 274       --  Index for start of match check. This can be negative if the pattern
 275       --  length is greater than the string length, which is why this variable
 276       --  is Integer instead of Natural. In this case, the search loops do not
 277       --  execute at all, so this Ind value is never used.
 278
 279    begin
 280       if Pattern = "" then
 281          raise Pattern_Error;
 282       end if;
 283
 284       --  Forwards case
 285
 286       if Going = Forward then
 287          Ind := Source'First;
 288
 289          --  Unmapped forward case
 290
 291          if Mapping'Address = Wide_Maps.Identity'Address then
 292             for J in 1 .. Source'Length - PL1 loop
 293                if Pattern = Source (Ind .. Ind + PL1) then
 294                   return Ind;
 295                else
 296                   Ind := Ind + 1;
 297                end if;
 298             end loop;
 299
 300          --  Mapped forward case
 301
 302          else
 303             for J in 1 .. Source'Length - PL1 loop
 304                Cur := Ind;
 305
 306                for K in Pattern'Range loop
 307                   if Pattern (K) /= Value (Mapping, Source (Cur)) then
 308                      goto Cont1;
 309                   else
 310                      Cur := Cur + 1;
 311                   end if;
 312                end loop;
 313
 314                return Ind;
 315
 316             <<Cont1>>
 317                Ind := Ind + 1;
 318             end loop;
 319          end if;
 320
 321       --  Backwards case
 322
 323       else
 324          --  Unmapped backward case
 325
 326          Ind := Source'Last - PL1;
 327
 328          if Mapping'Address = Wide_Maps.Identity'Address then
 329             for J in reverse 1 .. Source'Length - PL1 loop
 330                if Pattern = Source (Ind .. Ind + PL1) then
 331                   return Ind;
 332                else
 333                   Ind := Ind - 1;
 334                end if;
 335             end loop;
 336
 337          --  Mapped backward case
 338
 339          else
 340             for J in reverse 1 .. Source'Length - PL1 loop
 341                Cur := Ind;
 342
 343                for K in Pattern'Range loop
 344                   if Pattern (K) /= Value (Mapping, Source (Cur)) then
 345                      goto Cont2;
 346                   else
 347                      Cur := Cur + 1;
 348                   end if;
 349                end loop;
 350
 351                return Ind;
 352
 353             <<Cont2>>
 354                Ind := Ind - 1;
 355             end loop;
 356          end if;
 357       end if;
 358
 359       --  Fall through if no match found. Note that the loops are skipped
 360       --  completely in the case of the pattern being longer than the source.
 361
 362       return 0;
 363    end Index;
 364
 365    function Index
 366      (Source  : Wide_String;
 367       Pattern : Wide_String;
 368       Going   : Direction := Forward;
 369       Mapping : Wide_Maps.Wide_Character_Mapping_Function) return Natural
 370    is
 371       PL1 : constant Integer := Pattern'Length - 1;
 372       Ind : Natural;
 373       Cur : Natural;
 374
 375    begin
 376       if Pattern = "" then
 377          raise Pattern_Error;
 378       end if;
 379
 380       --  Check for null pointer in case checks are off
 381
 382       if Mapping = null then
 383          raise Constraint_Error;
 384       end if;
 385
 386       --  If Pattern longer than Source it can't be found
 387
 388       if Pattern'Length > Source'Length then
 389          return 0;
 390       end if;
 391
 392       --  Forwards case
 393
 394       if Going = Forward then
 395          Ind := Source'First;
 396          for J in 1 .. Source'Length - PL1 loop
 397             Cur := Ind;
 398
 399             for K in Pattern'Range loop
 400                if Pattern (K) /= Mapping.all (Source (Cur)) then
 401                   goto Cont1;
 402                else
 403                   Cur := Cur + 1;
 404                end if;
 405             end loop;
 406
 407             return Ind;
 408
 409          <<Cont1>>
 410             Ind := Ind + 1;
 411          end loop;
 412
 413       --  Backwards case
 414
 415       else
 416          Ind := Source'Last - PL1;
 417          for J in reverse 1 .. Source'Length - PL1 loop
 418             Cur := Ind;
 419
 420             for K in Pattern'Range loop
 421                if Pattern (K) /= Mapping.all (Source (Cur)) then
 422                   goto Cont2;
 423                else
 424                   Cur := Cur + 1;
 425                end if;
 426             end loop;
 427
 428             return Ind;
 429
 430          <<Cont2>>
 431             Ind := Ind - 1;
 432          end loop;
 433       end if;
 434
 435       --  Fall through if no match found. Note that the loops are skipped
 436       --  completely in the case of the pattern being longer than the source.
 437
 438       return 0;
 439    end Index;
 440
 441    function Index
 442      (Source : Wide_String;
 443       Set    : Wide_Maps.Wide_Character_Set;
 444       Test   : Membership := Inside;
 445       Going  : Direction  := Forward) return Natural
 446    is
 447    begin
 448       --  Forwards case
 449
 450       if Going = Forward then
 451          for J in Source'Range loop
 452             if Belongs (Source (J), Set, Test) then
 453                return J;
 454             end if;
 455          end loop;
 456
 457       --  Backwards case
 458
 459       else
 460          for J in reverse Source'Range loop
 461             if Belongs (Source (J), Set, Test) then
 462                return J;
 463             end if;
 464          end loop;
 465       end if;
 466
 467       --  Fall through if no match
 468
 469       return 0;
 470    end Index;
 471
 472    function Index
 473      (Source  : Wide_String;
 474       Pattern : Wide_String;
 475       From    : Positive;
 476       Going   : Direction := Forward;
 477       Mapping : Wide_Maps.Wide_Character_Mapping := Wide_Maps.Identity)
 478       return Natural
 479    is
 480    begin
 481       if Going = Forward then
 482          if From < Source'First then
 483             raise Index_Error;
 484          end if;
 485
 486          return
 487            Index (Source (From .. Source'Last), Pattern, Forward, Mapping);
 488
 489       else
 490          if From > Source'Last then
 491             raise Index_Error;
 492          end if;
 493
 494          return
 495            Index (Source (Source'First .. From), Pattern, Backward, Mapping);
 496       end if;
 497    end Index;
 498
 499    function Index
 500      (Source  : Wide_String;
 501       Pattern : Wide_String;
 502       From    : Positive;
 503       Going   : Direction := Forward;
 504       Mapping : Wide_Maps.Wide_Character_Mapping_Function) return Natural
 505    is
 506    begin
 507       if Going = Forward then
 508          if From < Source'First then
 509             raise Index_Error;
 510          end if;
 511
 512          return Index
 513            (Source (From .. Source'Last), Pattern, Forward, Mapping);
 514
 515       else
 516          if From > Source'Last then
 517             raise Index_Error;
 518          end if;
 519
 520          return Index
 521            (Source (Source'First .. From), Pattern, Backward, Mapping);
 522       end if;
 523    end Index;
 524
 525    function Index
 526      (Source  : Wide_String;
 527       Set     : Wide_Maps.Wide_Character_Set;
 528       From    : Positive;
 529       Test    : Membership := Inside;
 530       Going   : Direction := Forward) return Natural
 531    is
 532    begin
 533       if Going = Forward then
 534          if From < Source'First then
 535             raise Index_Error;
 536          end if;
 537
 538          return
 539            Index (Source (From .. Source'Last), Set, Test, Forward);
 540
 541       else
 542          if From > Source'Last then
 543             raise Index_Error;
 544          end if;
 545
 546          return
 547            Index (Source (Source'First .. From), Set, Test, Backward);
 548       end if;
 549    end Index;
 550
 551    ---------------------
 552    -- Index_Non_Blank --
 553    ---------------------
 554
 555    function Index_Non_Blank
 556      (Source : Wide_String;
 557       Going  : Direction := Forward) return Natural
 558    is
 559    begin
 560       if Going = Forward then
 561          for J in Source'Range loop
 562             if Source (J) /= Wide_Space then
 563                return J;
 564             end if;
 565          end loop;
 566
 567       else -- Going = Backward
 568          for J in reverse Source'Range loop
 569             if Source (J) /= Wide_Space then
 570                return J;
 571             end if;
 572          end loop;
 573       end if;
 574
 575       --  Fall through if no match
 576
 577       return 0;
 578    end Index_Non_Blank;
 579
 580    function Index_Non_Blank
 581      (Source : Wide_String;
 582       From   : Positive;
 583       Going  : Direction := Forward) return Natural
 584    is
 585    begin
 586       if Going = Forward then
 587          if From < Source'First then
 588             raise Index_Error;
 589          end if;
 590
 591          return
 592            Index_Non_Blank (Source (From .. Source'Last), Forward);
 593
 594       else
 595          if From > Source'Last then
 596             raise Index_Error;
 597          end if;
 598
 599          return
 600            Index_Non_Blank (Source (Source'First .. From), Backward);
 601       end if;
 602    end Index_Non_Blank;
 603
 604 end Ada.Strings.Wide_Search;