1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- A D A . S T R I N G S . S E A R C H --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
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. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- Note: This code is derived from the ADAR.CSH public domain Ada 83
33 -- versions of the Appendix C string handling packages (code extracted
34 -- from Ada.Strings.Fixed). A significant change is that we optimize the
35 -- case of identity mappings for Count and Index, and also Index_Non_Blank
36 -- is specialized (rather than using the general Index routine).
38 with Ada.Strings.Maps; use Ada.Strings.Maps;
39 with System; use System;
41 package body Ada.Strings.Search is
43 -----------------------
44 -- Local Subprograms --
45 -----------------------
49 Set : Maps.Character_Set;
50 Test : Membership) return Boolean;
51 pragma Inline (Belongs);
52 -- Determines if the given element is in (Test = Inside) or not in
53 -- (Test = Outside) the given character set.
61 Set : Maps.Character_Set;
62 Test : Membership) return Boolean
66 return Is_In (Element, Set);
68 return not Is_In (Element, Set);
79 Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
81 PL1 : constant Integer := Pattern'Length - 1;
96 if Mapping'Address = Maps.Identity'Address then
97 while Ind <= Source'Last - PL1 loop
98 if Pattern = Source (Ind .. Ind + PL1) then
100 Ind := Ind + Pattern'Length;
109 while Ind <= Source'Last - PL1 loop
111 for K in Pattern'Range loop
112 if Pattern (K) /= Value (Mapping, Source (Cur)) then
121 Ind := Ind + Pattern'Length;
136 Mapping : Maps.Character_Mapping_Function) return Natural
138 PL1 : constant Integer := Pattern'Length - 1;
148 -- Check for null pointer in case checks are off
150 if Mapping = null then
151 raise Constraint_Error;
156 while Ind <= Source'Last - PL1 loop
158 for K in Pattern'Range loop
159 if Pattern (K) /= Mapping (Source (Cur)) then
168 Ind := Ind + Pattern'Length;
179 Set : Maps.Character_Set) return Natural
184 for J in Source'Range loop
185 if Is_In (Source (J), Set) then
199 Set : Maps.Character_Set;
202 First : out Positive;
206 -- AI05-031: Raise Index error if Source non-empty and From not in range
208 if Source'Length /= 0 and then From not in Source'Range then
212 -- If Source is the empty string, From may still be out of its
213 -- range. The following ensures that in all cases there is no
214 -- possible erroneous access to a non-existing character.
216 for J in Integer'Max (From, Source'First) .. Source'Last loop
217 if Belongs (Source (J), Set, Test) then
220 for K in J + 1 .. Source'Last loop
221 if not Belongs (Source (K), Set, Test) then
227 -- Here if J indexes first char of token, and all chars after J
235 -- Here if no token found
243 Set : Maps.Character_Set;
245 First : out Positive;
249 for J in Source'Range loop
250 if Belongs (Source (J), Set, Test) then
253 for K in J + 1 .. Source'Last loop
254 if not Belongs (Source (K), Set, Test) then
260 -- Here if J indexes first char of token, and all chars after J
268 -- Here if no token found
270 -- RM 2005 A.4.3 (68/1) specifies that an exception must be raised if
271 -- Source'First is not positive and is assigned to First. Formulation
272 -- is slightly different in RM 2012, but the intent seems similar, so
273 -- we check explicitly for that condition.
275 if Source'First not in Positive then
276 raise Constraint_Error;
279 First := Source'First;
291 Going : Direction := Forward;
292 Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
294 PL1 : constant Integer := Pattern'Length - 1;
298 -- Index for start of match check. This can be negative if the pattern
299 -- length is greater than the string length, which is why this variable
300 -- is Integer instead of Natural. In this case, the search loops do not
301 -- execute at all, so this Ind value is never used.
310 if Going = Forward then
313 -- Unmapped forward case
315 if Mapping'Address = Maps.Identity'Address then
316 for J in 1 .. Source'Length - PL1 loop
317 if Pattern = Source (Ind .. Ind + PL1) then
324 -- Mapped forward case
327 for J in 1 .. Source'Length - PL1 loop
330 for K in Pattern'Range loop
331 if Pattern (K) /= Value (Mapping, Source (Cur)) then
348 -- Unmapped backward case
350 Ind := Source'Last - PL1;
352 if Mapping'Address = Maps.Identity'Address then
353 for J in reverse 1 .. Source'Length - PL1 loop
354 if Pattern = Source (Ind .. Ind + PL1) then
361 -- Mapped backward case
364 for J in reverse 1 .. Source'Length - PL1 loop
367 for K in Pattern'Range loop
368 if Pattern (K) /= Value (Mapping, Source (Cur)) then
383 -- Fall through if no match found. Note that the loops are skipped
384 -- completely in the case of the pattern being longer than the source.
392 Going : Direction := Forward;
393 Mapping : Maps.Character_Mapping_Function) return Natural
395 PL1 : constant Integer := Pattern'Length - 1;
404 -- Check for null pointer in case checks are off
406 if Mapping = null then
407 raise Constraint_Error;
410 -- If Pattern longer than Source it can't be found
412 if Pattern'Length > Source'Length then
418 if Going = Forward then
420 for J in 1 .. Source'Length - PL1 loop
423 for K in Pattern'Range loop
424 if Pattern (K) /= Mapping.all (Source (Cur)) then
440 Ind := Source'Last - PL1;
441 for J in reverse 1 .. Source'Length - PL1 loop
444 for K in Pattern'Range loop
445 if Pattern (K) /= Mapping.all (Source (Cur)) then
459 -- Fall through if no match found. Note that the loops are skipped
460 -- completely in the case of the pattern being longer than the source.
467 Set : Maps.Character_Set;
468 Test : Membership := Inside;
469 Going : Direction := Forward) return Natural
474 if Going = Forward then
475 for J in Source'Range loop
476 if Belongs (Source (J), Set, Test) then
484 for J in reverse Source'Range loop
485 if Belongs (Source (J), Set, Test) then
491 -- Fall through if no match
500 Going : Direction := Forward;
501 Mapping : Maps.Character_Mapping := Maps.Identity) return Natural
505 -- AI05-056: If source is empty result is always zero
507 if Source'Length = 0 then
510 elsif Going = Forward then
511 if From < Source'First then
516 Index (Source (From .. Source'Last), Pattern, Forward, Mapping);
519 if From > Source'Last then
524 Index (Source (Source'First .. From), Pattern, Backward, Mapping);
532 Going : Direction := Forward;
533 Mapping : Maps.Character_Mapping_Function) return Natural
537 -- AI05-056: If source is empty result is always zero
539 if Source'Length = 0 then
542 elsif Going = Forward then
543 if From < Source'First then
548 (Source (From .. Source'Last), Pattern, Forward, Mapping);
551 if From > Source'Last then
556 (Source (Source'First .. From), Pattern, Backward, Mapping);
562 Set : Maps.Character_Set;
564 Test : Membership := Inside;
565 Going : Direction := Forward) return Natural
569 -- AI05-056 : if source is empty result is always 0.
571 if Source'Length = 0 then
574 elsif Going = Forward then
575 if From < Source'First then
580 Index (Source (From .. Source'Last), Set, Test, Forward);
583 if From > Source'Last then
588 Index (Source (Source'First .. From), Set, Test, Backward);
592 ---------------------
593 -- Index_Non_Blank --
594 ---------------------
596 function Index_Non_Blank
598 Going : Direction := Forward) return Natural
601 if Going = Forward then
602 for J in Source'Range loop
603 if Source (J) /= ' ' then
608 else -- Going = Backward
609 for J in reverse Source'Range loop
610 if Source (J) /= ' ' then
616 -- Fall through if no match
621 function Index_Non_Blank
624 Going : Direction := Forward) return Natural
627 if Going = Forward then
628 if From < Source'First then
633 Index_Non_Blank (Source (From .. Source'Last), Forward);
636 if From > Source'Last then
641 Index_Non_Blank (Source (Source'First .. From), Backward);
645 end Ada.Strings.Search;