summaryrefslogtreecommitdiff
path: root/gcc/ada/a-strsea.adb
blob: 322aeaa7fb14fef284b440d021e1fe8d458cfc22 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT RUN-TIME COMPONENTS                         --
--                                                                          --
--                   A D A . S T R I N G S . S E A R C H                    --
--                                                                          --
--                                 B o d y                                  --
--                                                                          --
--          Copyright (C) 1992-2005, Free Software Foundation, Inc.         --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
-- Boston, MA 02110-1301, USA.                                              --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  Note: This code is derived from the ADAR.CSH public domain Ada 83
--  versions of the Appendix C string handling packages (code extracted
--  from Ada.Strings.Fixed). A significant change is that we optimize the
--  case of identity mappings for Count and Index, and also Index_Non_Blank
--  is specialized (rather than using the general Index routine).

with Ada.Strings.Maps; use Ada.Strings.Maps;

package body Ada.Strings.Search is

   -----------------------
   -- Local Subprograms --
   -----------------------

   function Belongs
     (Element : Character;
      Set     : Maps.Character_Set;
      Test    : Membership) return Boolean;
   pragma Inline (Belongs);
   --  Determines if the given element is in (Test = Inside) or not in
   --  (Test = Outside) the given character set.

   -------------
   -- Belongs --
   -------------

   function Belongs
     (Element : Character;
      Set     : Maps.Character_Set;
      Test    : Membership) return Boolean
   is
   begin
      if Test = Inside then
         return Is_In (Element, Set);
      else
         return not Is_In (Element, Set);
      end if;
   end Belongs;

   -----------
   -- Count --
   -----------

   function Count
     (Source  : String;
      Pattern : String;
      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
   is
      N : Natural;
      J : Natural;

      Mapped_Source : String (Source'Range);

   begin
      for J in Source'Range loop
         Mapped_Source (J) := Value (Mapping, Source (J));
      end loop;

      if Pattern = "" then
         raise Pattern_Error;
      end if;

      N := 0;
      J := Source'First;

      while J <= Source'Last - (Pattern'Length - 1) loop
         if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then
            N := N + 1;
            J := J + Pattern'Length;
         else
            J := J + 1;
         end if;
      end loop;

      return N;
   end Count;

   function Count
     (Source  : String;
      Pattern : String;
      Mapping : Maps.Character_Mapping_Function) return Natural
   is
      Mapped_Source : String (Source'Range);
      N             : Natural;
      J             : Natural;

   begin
      if Pattern = "" then
         raise Pattern_Error;
      end if;

      --  We make sure Access_Check is unsuppressed so that the Mapping.all
      --  call will generate a friendly Constraint_Error if the value for
      --  Mapping is uninitialized (and hence null).

      declare
         pragma Unsuppress (Access_Check);

      begin
         for J in Source'Range loop
            Mapped_Source (J) := Mapping.all (Source (J));
         end loop;
      end;

      N := 0;
      J := Source'First;

      while J <= Source'Last - (Pattern'Length - 1) loop
         if Mapped_Source (J .. J + (Pattern'Length - 1)) = Pattern then
            N := N + 1;
            J := J + Pattern'Length;
         else
            J := J + 1;
         end if;
      end loop;

      return N;
   end Count;

   function Count
     (Source : String;
      Set    : Maps.Character_Set) return Natural
   is
      N : Natural := 0;

   begin
      for J in Source'Range loop
         if Is_In (Source (J), Set) then
            N := N + 1;
         end if;
      end loop;

      return N;
   end Count;

   ----------------
   -- Find_Token --
   ----------------

   procedure Find_Token
     (Source : String;
      Set    : Maps.Character_Set;
      Test   : Membership;
      First  : out Positive;
      Last   : out Natural)
   is
   begin
      for J in Source'Range loop
         if Belongs (Source (J), Set, Test) then
            First := J;

            for K in J + 1 .. Source'Last loop
               if not Belongs (Source (K), Set, Test) then
                  Last := K - 1;
                  return;
               end if;
            end loop;

            --  Here if J indexes 1st char of token, and all chars
            --  after J are in the token

            Last := Source'Last;
            return;
         end if;
      end loop;

      --  Here if no token found

      First := Source'First;
      Last  := 0;
   end Find_Token;

   -----------
   -- Index --
   -----------

   function Index
     (Source  : String;
      Pattern : String;
      Going   : Direction := Forward;
      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
   is
      Cur_Index     : Natural;
      Mapped_Source : String (Source'Range);

   begin
      if Pattern = "" then
         raise Pattern_Error;
      end if;

      for J in Source'Range loop
         Mapped_Source (J) := Value (Mapping, Source (J));
      end loop;

      --  Forwards case

      if Going = Forward then
         for J in 1 .. Source'Length - Pattern'Length + 1 loop
            Cur_Index := Source'First + J - 1;

            if Pattern = Mapped_Source
                           (Cur_Index .. Cur_Index + Pattern'Length - 1)
            then
               return Cur_Index;
            end if;
         end loop;

      --  Backwards case

      else
         for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop
            Cur_Index := Source'First + J - 1;

            if Pattern = Mapped_Source
                           (Cur_Index .. Cur_Index + Pattern'Length - 1)
            then
               return Cur_Index;
            end if;
         end loop;
      end if;

      --  Fall through if no match found. Note that the loops are skipped
      --  completely in the case of the pattern being longer than the source.

      return 0;
   end Index;

   function Index
     (Source  : String;
      Pattern : String;
      Going   : Direction := Forward;
      Mapping : Maps.Character_Mapping_Function) return Natural
   is
      Mapped_Source : String (Source'Range);
      Cur_Index     : Natural;

   begin
      if Pattern = "" then
         raise Pattern_Error;
      end if;

      --  We make sure Access_Check is unsuppressed so that the Mapping.all
      --  call will generate a friendly Constraint_Error if the value for
      --  Mapping is uninitialized (and hence null).

      declare
         pragma Unsuppress (Access_Check);
      begin
         for J in Source'Range loop
            Mapped_Source (J) := Mapping.all (Source (J));
         end loop;
      end;

      --  Forwards case

      if Going = Forward then
         for J in 1 .. Source'Length - Pattern'Length + 1 loop
            Cur_Index := Source'First + J - 1;

            if Pattern = Mapped_Source
                           (Cur_Index .. Cur_Index + Pattern'Length - 1)
            then
               return Cur_Index;
            end if;
         end loop;

      --  Backwards case

      else
         for J in reverse 1 .. Source'Length - Pattern'Length + 1 loop
            Cur_Index := Source'First + J - 1;

            if Pattern = Mapped_Source
                           (Cur_Index .. Cur_Index + Pattern'Length - 1)
            then
               return Cur_Index;
            end if;
         end loop;
      end if;

      return 0;
   end Index;

   function Index
     (Source : String;
      Set    : Maps.Character_Set;
      Test   : Membership := Inside;
      Going  : Direction  := Forward) return Natural
   is
   begin
      --  Forwards case

      if Going = Forward then
         for J in Source'Range loop
            if Belongs (Source (J), Set, Test) then
               return J;
            end if;
         end loop;

      --  Backwards case

      else
         for J in reverse Source'Range loop
            if Belongs (Source (J), Set, Test) then
               return J;
            end if;
         end loop;
      end if;

      --  Fall through if no match

      return 0;
   end Index;

   function Index
     (Source  : String;
      Pattern : String;
      From    : Positive;
      Going   : Direction := Forward;
      Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
   is
   begin
      if Going = Forward then
         if From < Source'First then
            raise Index_Error;
         end if;

         return
           Index (Source (From .. Source'Last), Pattern, Forward, Mapping);

      else
         if From > Source'Last then
            raise Index_Error;
         end if;

         return
           Index (Source (Source'First .. From), Pattern, Backward, Mapping);
      end if;
   end Index;

   function Index
     (Source  : String;
      Pattern : String;
      From    : Positive;
      Going   : Direction := Forward;
      Mapping : Maps.Character_Mapping_Function) return Natural
   is
   begin
      if Going = Forward then
         if From < Source'First then
            raise Index_Error;
         end if;

         return Index
           (Source (From .. Source'Last), Pattern, Forward, Mapping);

      else
         if From > Source'Last then
            raise Index_Error;
         end if;

         return Index
           (Source (Source'First .. From), Pattern, Backward, Mapping);
      end if;
   end Index;

   function Index
     (Source  : String;
      Set     : Maps.Character_Set;
      From    : Positive;
      Test    : Membership := Inside;
      Going   : Direction := Forward) return Natural
   is
   begin
      if Going = Forward then
         if From < Source'First then
            raise Index_Error;
         end if;

         return
           Index (Source (From .. Source'Last), Set, Test, Forward);

      else
         if From > Source'Last then
            raise Index_Error;
         end if;

         return
           Index (Source (Source'First .. From), Set, Test, Backward);
      end if;
   end Index;

   ---------------------
   -- Index_Non_Blank --
   ---------------------

   function Index_Non_Blank
     (Source : String;
      Going  : Direction := Forward) return Natural
   is
   begin
      if Going = Forward then
         for J in Source'Range loop
            if Source (J) /= ' ' then
               return J;
            end if;
         end loop;

      else -- Going = Backward
         for J in reverse Source'Range loop
            if Source (J) /= ' ' then
               return J;
            end if;
         end loop;
      end if;

      --  Fall through if no match

      return 0;
   end Index_Non_Blank;

   function Index_Non_Blank
     (Source : String;
      From   : Positive;
      Going  : Direction := Forward) return Natural
   is
   begin
      if Going = Forward then
         if From < Source'First then
            raise Index_Error;
         end if;

         return
           Index_Non_Blank (Source (From .. Source'Last), Forward);

      else
         if From > Source'Last then
            raise Index_Error;
         end if;

         return
           Index_Non_Blank (Source (Source'First .. From), Backward);
      end if;
   end Index_Non_Blank;

end Ada.Strings.Search;