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1e194575 AC |
1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT LIBRARY COMPONENTS -- | |
4 | -- -- | |
5 | -- A D A . C O N T A I N E R S . B O U N D E D _ V E C T O R S -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
b727a82b | 9 | -- Copyright (C) 2004-2012, Free Software Foundation, Inc. -- |
1e194575 AC |
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 | -- This unit was originally developed by Matthew J Heaney. -- | |
28 | ------------------------------------------------------------------------------ | |
29 | ||
30 | with Ada.Containers.Generic_Array_Sort; | |
ef992452 | 31 | with Ada.Finalization; use Ada.Finalization; |
e47e21c1 | 32 | |
1e194575 AC |
33 | with System; use type System.Address; |
34 | ||
35 | package body Ada.Containers.Bounded_Vectors is | |
36 | ||
ef992452 AC |
37 | type Iterator is new Limited_Controlled and |
38 | Vector_Iterator_Interfaces.Reversible_Iterator with | |
39 | record | |
40 | Container : Vector_Access; | |
e8bd500e | 41 | Index : Index_Type'Base; |
ef992452 AC |
42 | end record; |
43 | ||
44 | overriding procedure Finalize (Object : in out Iterator); | |
a6dd3a54 ES |
45 | |
46 | overriding function First (Object : Iterator) return Cursor; | |
47 | overriding function Last (Object : Iterator) return Cursor; | |
48 | ||
49 | overriding function Next | |
50 | (Object : Iterator; | |
51 | Position : Cursor) return Cursor; | |
52 | ||
53 | overriding function Previous | |
54 | (Object : Iterator; | |
55 | Position : Cursor) return Cursor; | |
56 | ||
1e194575 AC |
57 | ----------------------- |
58 | -- Local Subprograms -- | |
59 | ----------------------- | |
60 | ||
61 | function To_Array_Index (Index : Index_Type'Base) return Count_Type'Base; | |
62 | ||
63 | --------- | |
64 | -- "&" -- | |
65 | --------- | |
66 | ||
67 | function "&" (Left, Right : Vector) return Vector is | |
68 | LN : constant Count_Type := Length (Left); | |
69 | RN : constant Count_Type := Length (Right); | |
70 | N : Count_Type'Base; -- length of result | |
71 | J : Count_Type'Base; -- for computing intermediate index values | |
72 | Last : Index_Type'Base; -- Last index of result | |
73 | ||
74 | begin | |
75 | -- We decide that the capacity of the result is the sum of the lengths | |
76 | -- of the vector parameters. We could decide to make it larger, but we | |
77 | -- have no basis for knowing how much larger, so we just allocate the | |
78 | -- minimum amount of storage. | |
79 | ||
80 | -- Here we handle the easy cases first, when one of the vector | |
81 | -- parameters is empty. (We say "easy" because there's nothing to | |
82 | -- compute, that can potentially overflow.) | |
83 | ||
84 | if LN = 0 then | |
85 | if RN = 0 then | |
86 | return Empty_Vector; | |
87 | end if; | |
88 | ||
89 | return Vector'(Capacity => RN, | |
90 | Elements => Right.Elements (1 .. RN), | |
91 | Last => Right.Last, | |
92 | others => <>); | |
93 | end if; | |
94 | ||
95 | if RN = 0 then | |
96 | return Vector'(Capacity => LN, | |
97 | Elements => Left.Elements (1 .. LN), | |
98 | Last => Left.Last, | |
99 | others => <>); | |
100 | end if; | |
101 | ||
102 | -- Neither of the vector parameters is empty, so must compute the length | |
103 | -- of the result vector and its last index. (This is the harder case, | |
104 | -- because our computations must avoid overflow.) | |
105 | ||
106 | -- There are two constraints we need to satisfy. The first constraint is | |
107 | -- that a container cannot have more than Count_Type'Last elements, so | |
108 | -- we must check the sum of the combined lengths. Note that we cannot | |
308e6f3a | 109 | -- simply add the lengths, because of the possibility of overflow. |
1e194575 AC |
110 | |
111 | if LN > Count_Type'Last - RN then | |
112 | raise Constraint_Error with "new length is out of range"; | |
113 | end if; | |
114 | ||
115 | -- It is now safe compute the length of the new vector, without fear of | |
116 | -- overflow. | |
117 | ||
118 | N := LN + RN; | |
119 | ||
120 | -- The second constraint is that the new Last index value cannot | |
121 | -- exceed Index_Type'Last. We use the wider of Index_Type'Base and | |
122 | -- Count_Type'Base as the type for intermediate values. | |
123 | ||
124 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
125 | -- We perform a two-part test. First we determine whether the | |
126 | -- computed Last value lies in the base range of the type, and then | |
127 | -- determine whether it lies in the range of the index (sub)type. | |
128 | ||
129 | -- Last must satisfy this relation: | |
130 | -- First + Length - 1 <= Last | |
131 | -- We regroup terms: | |
132 | -- First - 1 <= Last - Length | |
133 | -- Which can rewrite as: | |
134 | -- No_Index <= Last - Length | |
135 | ||
136 | if Index_Type'Base'Last - Index_Type'Base (N) < No_Index then | |
137 | raise Constraint_Error with "new length is out of range"; | |
138 | end if; | |
139 | ||
140 | -- We now know that the computed value of Last is within the base | |
141 | -- range of the type, so it is safe to compute its value: | |
142 | ||
143 | Last := No_Index + Index_Type'Base (N); | |
144 | ||
145 | -- Finally we test whether the value is within the range of the | |
146 | -- generic actual index subtype: | |
147 | ||
148 | if Last > Index_Type'Last then | |
149 | raise Constraint_Error with "new length is out of range"; | |
150 | end if; | |
151 | ||
152 | elsif Index_Type'First <= 0 then | |
153 | -- Here we can compute Last directly, in the normal way. We know that | |
154 | -- No_Index is less than 0, so there is no danger of overflow when | |
155 | -- adding the (positive) value of length. | |
156 | ||
157 | J := Count_Type'Base (No_Index) + N; -- Last | |
158 | ||
159 | if J > Count_Type'Base (Index_Type'Last) then | |
160 | raise Constraint_Error with "new length is out of range"; | |
161 | end if; | |
162 | ||
163 | -- We know that the computed value (having type Count_Type) of Last | |
164 | -- is within the range of the generic actual index subtype, so it is | |
165 | -- safe to convert to Index_Type: | |
166 | ||
167 | Last := Index_Type'Base (J); | |
168 | ||
169 | else | |
170 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we | |
171 | -- must test the length indirectly (by working backwards from the | |
172 | -- largest possible value of Last), in order to prevent overflow. | |
173 | ||
174 | J := Count_Type'Base (Index_Type'Last) - N; -- No_Index | |
175 | ||
176 | if J < Count_Type'Base (No_Index) then | |
177 | raise Constraint_Error with "new length is out of range"; | |
178 | end if; | |
179 | ||
180 | -- We have determined that the result length would not create a Last | |
181 | -- index value outside of the range of Index_Type, so we can now | |
182 | -- safely compute its value. | |
183 | ||
184 | Last := Index_Type'Base (Count_Type'Base (No_Index) + N); | |
185 | end if; | |
186 | ||
187 | declare | |
188 | LE : Elements_Array renames Left.Elements (1 .. LN); | |
189 | RE : Elements_Array renames Right.Elements (1 .. RN); | |
190 | ||
191 | begin | |
192 | return Vector'(Capacity => N, | |
193 | Elements => LE & RE, | |
194 | Last => Last, | |
195 | others => <>); | |
196 | end; | |
197 | end "&"; | |
198 | ||
199 | function "&" (Left : Vector; Right : Element_Type) return Vector is | |
200 | LN : constant Count_Type := Length (Left); | |
201 | ||
202 | begin | |
203 | -- We decide that the capacity of the result is the sum of the lengths | |
204 | -- of the parameters. We could decide to make it larger, but we have no | |
205 | -- basis for knowing how much larger, so we just allocate the minimum | |
206 | -- amount of storage. | |
207 | ||
208 | -- We must compute the length of the result vector and its last index, | |
209 | -- but in such a way that overflow is avoided. We must satisfy two | |
210 | -- constraints: the new length cannot exceed Count_Type'Last, and the | |
211 | -- new Last index cannot exceed Index_Type'Last. | |
212 | ||
213 | if LN = Count_Type'Last then | |
214 | raise Constraint_Error with "new length is out of range"; | |
215 | end if; | |
216 | ||
217 | if Left.Last >= Index_Type'Last then | |
218 | raise Constraint_Error with "new length is out of range"; | |
219 | end if; | |
220 | ||
221 | return Vector'(Capacity => LN + 1, | |
222 | Elements => Left.Elements (1 .. LN) & Right, | |
223 | Last => Left.Last + 1, | |
224 | others => <>); | |
225 | end "&"; | |
226 | ||
227 | function "&" (Left : Element_Type; Right : Vector) return Vector is | |
228 | RN : constant Count_Type := Length (Right); | |
229 | ||
230 | begin | |
231 | -- We decide that the capacity of the result is the sum of the lengths | |
232 | -- of the parameters. We could decide to make it larger, but we have no | |
233 | -- basis for knowing how much larger, so we just allocate the minimum | |
234 | -- amount of storage. | |
235 | ||
236 | -- We compute the length of the result vector and its last index, but in | |
237 | -- such a way that overflow is avoided. We must satisfy two constraints: | |
238 | -- the new length cannot exceed Count_Type'Last, and the new Last index | |
239 | -- cannot exceed Index_Type'Last. | |
240 | ||
241 | if RN = Count_Type'Last then | |
242 | raise Constraint_Error with "new length is out of range"; | |
243 | end if; | |
244 | ||
245 | if Right.Last >= Index_Type'Last then | |
246 | raise Constraint_Error with "new length is out of range"; | |
247 | end if; | |
248 | ||
249 | return Vector'(Capacity => 1 + RN, | |
250 | Elements => Left & Right.Elements (1 .. RN), | |
251 | Last => Right.Last + 1, | |
252 | others => <>); | |
253 | end "&"; | |
254 | ||
255 | function "&" (Left, Right : Element_Type) return Vector is | |
256 | begin | |
257 | -- We decide that the capacity of the result is the sum of the lengths | |
258 | -- of the parameters. We could decide to make it larger, but we have no | |
259 | -- basis for knowing how much larger, so we just allocate the minimum | |
260 | -- amount of storage. | |
261 | ||
262 | -- We must compute the length of the result vector and its last index, | |
263 | -- but in such a way that overflow is avoided. We must satisfy two | |
264 | -- constraints: the new length cannot exceed Count_Type'Last (here, we | |
265 | -- know that that condition is satisfied), and the new Last index cannot | |
266 | -- exceed Index_Type'Last. | |
267 | ||
268 | if Index_Type'First >= Index_Type'Last then | |
269 | raise Constraint_Error with "new length is out of range"; | |
270 | end if; | |
271 | ||
272 | return Vector'(Capacity => 2, | |
273 | Elements => (Left, Right), | |
274 | Last => Index_Type'First + 1, | |
275 | others => <>); | |
276 | end "&"; | |
277 | ||
278 | --------- | |
279 | -- "=" -- | |
280 | --------- | |
281 | ||
282 | overriding function "=" (Left, Right : Vector) return Boolean is | |
283 | begin | |
284 | if Left'Address = Right'Address then | |
285 | return True; | |
286 | end if; | |
287 | ||
288 | if Left.Last /= Right.Last then | |
289 | return False; | |
290 | end if; | |
291 | ||
292 | for J in Count_Type range 1 .. Left.Length loop | |
293 | if Left.Elements (J) /= Right.Elements (J) then | |
294 | return False; | |
295 | end if; | |
296 | end loop; | |
297 | ||
298 | return True; | |
299 | end "="; | |
300 | ||
301 | ------------ | |
302 | -- Assign -- | |
303 | ------------ | |
304 | ||
305 | procedure Assign (Target : in out Vector; Source : Vector) is | |
306 | begin | |
307 | if Target'Address = Source'Address then | |
308 | return; | |
309 | end if; | |
310 | ||
311 | if Target.Capacity < Source.Length then | |
312 | raise Capacity_Error -- ??? | |
313 | with "Target capacity is less than Source length"; | |
314 | end if; | |
315 | ||
316 | Target.Clear; | |
317 | ||
318 | Target.Elements (1 .. Source.Length) := | |
319 | Source.Elements (1 .. Source.Length); | |
320 | ||
321 | Target.Last := Source.Last; | |
322 | end Assign; | |
323 | ||
324 | ------------ | |
325 | -- Append -- | |
326 | ------------ | |
327 | ||
328 | procedure Append (Container : in out Vector; New_Item : Vector) is | |
329 | begin | |
330 | if New_Item.Is_Empty then | |
331 | return; | |
332 | end if; | |
333 | ||
334 | if Container.Last >= Index_Type'Last then | |
335 | raise Constraint_Error with "vector is already at its maximum length"; | |
336 | end if; | |
337 | ||
338 | Container.Insert (Container.Last + 1, New_Item); | |
339 | end Append; | |
340 | ||
341 | procedure Append | |
342 | (Container : in out Vector; | |
343 | New_Item : Element_Type; | |
344 | Count : Count_Type := 1) | |
345 | is | |
346 | begin | |
347 | if Count = 0 then | |
348 | return; | |
349 | end if; | |
350 | ||
351 | if Container.Last >= Index_Type'Last then | |
352 | raise Constraint_Error with "vector is already at its maximum length"; | |
353 | end if; | |
354 | ||
355 | Container.Insert (Container.Last + 1, New_Item, Count); | |
356 | end Append; | |
357 | ||
358 | -------------- | |
359 | -- Capacity -- | |
360 | -------------- | |
361 | ||
362 | function Capacity (Container : Vector) return Count_Type is | |
363 | begin | |
364 | return Container.Elements'Length; | |
365 | end Capacity; | |
366 | ||
367 | ----------- | |
368 | -- Clear -- | |
369 | ----------- | |
370 | ||
371 | procedure Clear (Container : in out Vector) is | |
372 | begin | |
373 | if Container.Busy > 0 then | |
374 | raise Program_Error with | |
375 | "attempt to tamper with cursors (vector is busy)"; | |
376 | end if; | |
377 | ||
378 | Container.Last := No_Index; | |
379 | end Clear; | |
380 | ||
c9423ca3 AC |
381 | ------------------------ |
382 | -- Constant_Reference -- | |
383 | ------------------------ | |
384 | ||
385 | function Constant_Reference | |
386 | (Container : aliased Vector; | |
387 | Position : Cursor) return Constant_Reference_Type | |
388 | is | |
389 | begin | |
390 | if Position.Container = null then | |
391 | raise Constraint_Error with "Position cursor has no element"; | |
392 | end if; | |
393 | ||
394 | if Position.Container /= Container'Unrestricted_Access then | |
395 | raise Program_Error with "Position cursor denotes wrong container"; | |
396 | end if; | |
397 | ||
398 | if Position.Index > Position.Container.Last then | |
399 | raise Constraint_Error with "Position cursor is out of range"; | |
400 | end if; | |
401 | ||
402 | declare | |
403 | A : Elements_Array renames Container.Elements; | |
404 | I : constant Count_Type := To_Array_Index (Position.Index); | |
405 | begin | |
406 | return (Element => A (I)'Access); | |
407 | end; | |
408 | end Constant_Reference; | |
409 | ||
410 | function Constant_Reference | |
411 | (Container : aliased Vector; | |
412 | Index : Index_Type) return Constant_Reference_Type | |
413 | is | |
414 | begin | |
415 | if Index > Container.Last then | |
416 | raise Constraint_Error with "Index is out of range"; | |
417 | end if; | |
418 | ||
419 | declare | |
420 | A : Elements_Array renames Container.Elements; | |
421 | I : constant Count_Type := To_Array_Index (Index); | |
422 | begin | |
423 | return (Element => A (I)'Access); | |
424 | end; | |
425 | end Constant_Reference; | |
426 | ||
1e194575 AC |
427 | -------------- |
428 | -- Contains -- | |
429 | -------------- | |
430 | ||
431 | function Contains | |
432 | (Container : Vector; | |
433 | Item : Element_Type) return Boolean | |
434 | is | |
435 | begin | |
436 | return Find_Index (Container, Item) /= No_Index; | |
437 | end Contains; | |
438 | ||
439 | ---------- | |
440 | -- Copy -- | |
441 | ---------- | |
442 | ||
443 | function Copy | |
444 | (Source : Vector; | |
445 | Capacity : Count_Type := 0) return Vector | |
446 | is | |
447 | C : Count_Type; | |
448 | ||
449 | begin | |
450 | if Capacity = 0 then | |
451 | C := Source.Length; | |
452 | ||
453 | elsif Capacity >= Source.Length then | |
454 | C := Capacity; | |
455 | ||
456 | else | |
457 | raise Capacity_Error | |
458 | with "Requested capacity is less than Source length"; | |
459 | end if; | |
460 | ||
461 | return Target : Vector (C) do | |
462 | Target.Elements (1 .. Source.Length) := | |
463 | Source.Elements (1 .. Source.Length); | |
464 | ||
465 | Target.Last := Source.Last; | |
466 | end return; | |
467 | end Copy; | |
468 | ||
469 | ------------ | |
470 | -- Delete -- | |
471 | ------------ | |
472 | ||
473 | procedure Delete | |
474 | (Container : in out Vector; | |
475 | Index : Extended_Index; | |
476 | Count : Count_Type := 1) | |
477 | is | |
478 | Old_Last : constant Index_Type'Base := Container.Last; | |
479 | Old_Len : constant Count_Type := Container.Length; | |
480 | New_Last : Index_Type'Base; | |
481 | Count2 : Count_Type'Base; -- count of items from Index to Old_Last | |
482 | Off : Count_Type'Base; -- Index expressed as offset from IT'First | |
483 | ||
484 | begin | |
485 | -- Delete removes items from the vector, the number of which is the | |
486 | -- minimum of the specified Count and the items (if any) that exist from | |
487 | -- Index to Container.Last. There are no constraints on the specified | |
488 | -- value of Count (it can be larger than what's available at this | |
489 | -- position in the vector, for example), but there are constraints on | |
490 | -- the allowed values of the Index. | |
491 | ||
492 | -- As a precondition on the generic actual Index_Type, the base type | |
493 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
494 | -- that Container.Last assumes when the vector is empty. However, we do | |
495 | -- not allow that as the value for Index when specifying which items | |
496 | -- should be deleted, so we must manually check. (That the user is | |
497 | -- allowed to specify the value at all here is a consequence of the | |
498 | -- declaration of the Extended_Index subtype, which includes the values | |
499 | -- in the base range that immediately precede and immediately follow the | |
500 | -- values in the Index_Type.) | |
501 | ||
502 | if Index < Index_Type'First then | |
503 | raise Constraint_Error with "Index is out of range (too small)"; | |
504 | end if; | |
505 | ||
506 | -- We do allow a value greater than Container.Last to be specified as | |
507 | -- the Index, but only if it's immediately greater. This allows the | |
508 | -- corner case of deleting no items from the back end of the vector to | |
509 | -- be treated as a no-op. (It is assumed that specifying an index value | |
510 | -- greater than Last + 1 indicates some deeper flaw in the caller's | |
511 | -- algorithm, so that case is treated as a proper error.) | |
512 | ||
513 | if Index > Old_Last then | |
514 | if Index > Old_Last + 1 then | |
515 | raise Constraint_Error with "Index is out of range (too large)"; | |
516 | end if; | |
517 | ||
518 | return; | |
519 | end if; | |
520 | ||
521 | -- Here and elsewhere we treat deleting 0 items from the container as a | |
522 | -- no-op, even when the container is busy, so we simply return. | |
523 | ||
524 | if Count = 0 then | |
525 | return; | |
526 | end if; | |
527 | ||
528 | -- The tampering bits exist to prevent an item from being deleted (or | |
529 | -- otherwise harmfully manipulated) while it is being visited. Query, | |
530 | -- Update, and Iterate increment the busy count on entry, and decrement | |
531 | -- the count on exit. Delete checks the count to determine whether it is | |
532 | -- being called while the associated callback procedure is executing. | |
533 | ||
534 | if Container.Busy > 0 then | |
535 | raise Program_Error with | |
536 | "attempt to tamper with cursors (vector is busy)"; | |
537 | end if; | |
538 | ||
539 | -- We first calculate what's available for deletion starting at | |
540 | -- Index. Here and elsewhere we use the wider of Index_Type'Base and | |
541 | -- Count_Type'Base as the type for intermediate values. (See function | |
542 | -- Length for more information.) | |
543 | ||
544 | if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then | |
545 | Count2 := Count_Type'Base (Old_Last) - Count_Type'Base (Index) + 1; | |
546 | ||
547 | else | |
548 | Count2 := Count_Type'Base (Old_Last - Index + 1); | |
549 | end if; | |
550 | ||
551 | -- If more elements are requested (Count) for deletion than are | |
552 | -- available (Count2) for deletion beginning at Index, then everything | |
553 | -- from Index is deleted. There are no elements to slide down, and so | |
554 | -- all we need to do is set the value of Container.Last. | |
555 | ||
556 | if Count >= Count2 then | |
557 | Container.Last := Index - 1; | |
558 | return; | |
559 | end if; | |
560 | ||
561 | -- There are some elements aren't being deleted (the requested count was | |
562 | -- less than the available count), so we must slide them down to | |
563 | -- Index. We first calculate the index values of the respective array | |
564 | -- slices, using the wider of Index_Type'Base and Count_Type'Base as the | |
565 | -- type for intermediate calculations. | |
566 | ||
567 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
568 | Off := Count_Type'Base (Index - Index_Type'First); | |
569 | New_Last := Old_Last - Index_Type'Base (Count); | |
570 | ||
571 | else | |
572 | Off := Count_Type'Base (Index) - Count_Type'Base (Index_Type'First); | |
573 | New_Last := Index_Type'Base (Count_Type'Base (Old_Last) - Count); | |
574 | end if; | |
575 | ||
576 | -- The array index values for each slice have already been determined, | |
577 | -- so we just slide down to Index the elements that weren't deleted. | |
578 | ||
579 | declare | |
580 | EA : Elements_Array renames Container.Elements; | |
581 | Idx : constant Count_Type := EA'First + Off; | |
582 | ||
583 | begin | |
584 | EA (Idx .. Old_Len - Count) := EA (Idx + Count .. Old_Len); | |
585 | Container.Last := New_Last; | |
586 | end; | |
587 | end Delete; | |
588 | ||
589 | procedure Delete | |
590 | (Container : in out Vector; | |
591 | Position : in out Cursor; | |
592 | Count : Count_Type := 1) | |
593 | is | |
594 | pragma Warnings (Off, Position); | |
595 | ||
596 | begin | |
597 | if Position.Container = null then | |
598 | raise Constraint_Error with "Position cursor has no element"; | |
599 | end if; | |
600 | ||
601 | if Position.Container /= Container'Unrestricted_Access then | |
602 | raise Program_Error with "Position cursor denotes wrong container"; | |
603 | end if; | |
604 | ||
605 | if Position.Index > Container.Last then | |
606 | raise Program_Error with "Position index is out of range"; | |
607 | end if; | |
608 | ||
609 | Delete (Container, Position.Index, Count); | |
610 | Position := No_Element; | |
611 | end Delete; | |
612 | ||
613 | ------------------ | |
614 | -- Delete_First -- | |
615 | ------------------ | |
616 | ||
617 | procedure Delete_First | |
618 | (Container : in out Vector; | |
619 | Count : Count_Type := 1) | |
620 | is | |
621 | begin | |
622 | if Count = 0 then | |
623 | return; | |
624 | end if; | |
625 | ||
626 | if Count >= Length (Container) then | |
627 | Clear (Container); | |
628 | return; | |
629 | end if; | |
630 | ||
631 | Delete (Container, Index_Type'First, Count); | |
632 | end Delete_First; | |
633 | ||
634 | ----------------- | |
635 | -- Delete_Last -- | |
636 | ----------------- | |
637 | ||
638 | procedure Delete_Last | |
639 | (Container : in out Vector; | |
640 | Count : Count_Type := 1) | |
641 | is | |
642 | begin | |
643 | -- It is not permitted to delete items while the container is busy (for | |
644 | -- example, we're in the middle of a passive iteration). However, we | |
645 | -- always treat deleting 0 items as a no-op, even when we're busy, so we | |
646 | -- simply return without checking. | |
647 | ||
648 | if Count = 0 then | |
649 | return; | |
650 | end if; | |
651 | ||
652 | -- The tampering bits exist to prevent an item from being deleted (or | |
653 | -- otherwise harmfully manipulated) while it is being visited. Query, | |
654 | -- Update, and Iterate increment the busy count on entry, and decrement | |
655 | -- the count on exit. Delete_Last checks the count to determine whether | |
656 | -- it is being called while the associated callback procedure is | |
657 | -- executing. | |
658 | ||
659 | if Container.Busy > 0 then | |
660 | raise Program_Error with | |
661 | "attempt to tamper with cursors (vector is busy)"; | |
662 | end if; | |
663 | ||
664 | -- There is no restriction on how large Count can be when deleting | |
665 | -- items. If it is equal or greater than the current length, then this | |
666 | -- is equivalent to clearing the vector. (In particular, there's no need | |
667 | -- for us to actually calculate the new value for Last.) | |
668 | ||
669 | -- If the requested count is less than the current length, then we must | |
670 | -- calculate the new value for Last. For the type we use the widest of | |
671 | -- Index_Type'Base and Count_Type'Base for the intermediate values of | |
672 | -- our calculation. (See the comments in Length for more information.) | |
673 | ||
674 | if Count >= Container.Length then | |
675 | Container.Last := No_Index; | |
676 | ||
677 | elsif Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
678 | Container.Last := Container.Last - Index_Type'Base (Count); | |
679 | ||
680 | else | |
681 | Container.Last := | |
682 | Index_Type'Base (Count_Type'Base (Container.Last) - Count); | |
683 | end if; | |
684 | end Delete_Last; | |
685 | ||
686 | ------------- | |
687 | -- Element -- | |
688 | ------------- | |
689 | ||
690 | function Element | |
691 | (Container : Vector; | |
692 | Index : Index_Type) return Element_Type | |
693 | is | |
694 | begin | |
695 | if Index > Container.Last then | |
696 | raise Constraint_Error with "Index is out of range"; | |
d85fd922 AC |
697 | else |
698 | return Container.Elements (To_Array_Index (Index)); | |
1e194575 | 699 | end if; |
1e194575 AC |
700 | end Element; |
701 | ||
702 | function Element (Position : Cursor) return Element_Type is | |
703 | begin | |
704 | if Position.Container = null then | |
705 | raise Constraint_Error with "Position cursor has no element"; | |
d85fd922 AC |
706 | else |
707 | return Position.Container.Element (Position.Index); | |
1e194575 | 708 | end if; |
1e194575 AC |
709 | end Element; |
710 | ||
ef992452 AC |
711 | -------------- |
712 | -- Finalize -- | |
713 | -------------- | |
714 | ||
715 | procedure Finalize (Object : in out Iterator) is | |
e8bd500e | 716 | B : Natural renames Object.Container.Busy; |
ef992452 | 717 | begin |
e8bd500e | 718 | B := B - 1; |
ef992452 AC |
719 | end Finalize; |
720 | ||
1e194575 AC |
721 | ---------- |
722 | -- Find -- | |
723 | ---------- | |
724 | ||
725 | function Find | |
726 | (Container : Vector; | |
727 | Item : Element_Type; | |
728 | Position : Cursor := No_Element) return Cursor | |
729 | is | |
730 | begin | |
731 | if Position.Container /= null then | |
732 | if Position.Container /= Container'Unrestricted_Access then | |
733 | raise Program_Error with "Position cursor denotes wrong container"; | |
734 | end if; | |
735 | ||
736 | if Position.Index > Container.Last then | |
737 | raise Program_Error with "Position index is out of range"; | |
738 | end if; | |
739 | end if; | |
740 | ||
741 | for J in Position.Index .. Container.Last loop | |
742 | if Container.Elements (To_Array_Index (J)) = Item then | |
743 | return (Container'Unrestricted_Access, J); | |
744 | end if; | |
745 | end loop; | |
746 | ||
747 | return No_Element; | |
748 | end Find; | |
749 | ||
750 | ---------------- | |
751 | -- Find_Index -- | |
752 | ---------------- | |
753 | ||
754 | function Find_Index | |
755 | (Container : Vector; | |
756 | Item : Element_Type; | |
757 | Index : Index_Type := Index_Type'First) return Extended_Index | |
758 | is | |
759 | begin | |
760 | for Indx in Index .. Container.Last loop | |
761 | if Container.Elements (To_Array_Index (Indx)) = Item then | |
762 | return Indx; | |
763 | end if; | |
764 | end loop; | |
765 | ||
766 | return No_Index; | |
767 | end Find_Index; | |
768 | ||
769 | ----------- | |
770 | -- First -- | |
771 | ----------- | |
772 | ||
773 | function First (Container : Vector) return Cursor is | |
774 | begin | |
775 | if Is_Empty (Container) then | |
776 | return No_Element; | |
d85fd922 AC |
777 | else |
778 | return (Container'Unrestricted_Access, Index_Type'First); | |
1e194575 | 779 | end if; |
1e194575 AC |
780 | end First; |
781 | ||
a6dd3a54 ES |
782 | function First (Object : Iterator) return Cursor is |
783 | begin | |
e8bd500e AC |
784 | -- The value of the iterator object's Index component influences the |
785 | -- behavior of the First (and Last) selector function. | |
786 | ||
fe58fea7 AC |
787 | -- When the Index component is No_Index, this means the iterator |
788 | -- object was constructed without a start expression, in which case the | |
e8bd500e AC |
789 | -- (forward) iteration starts from the (logical) beginning of the entire |
790 | -- sequence of items (corresponding to Container.First, for a forward | |
791 | -- iterator). | |
792 | ||
fe58fea7 AC |
793 | -- Otherwise, this is iteration over a partial sequence of items. |
794 | -- When the Index component isn't No_Index, the iterator object was | |
795 | -- constructed with a start expression, that specifies the position | |
796 | -- from which the (forward) partial iteration begins. | |
e8bd500e AC |
797 | |
798 | if Object.Index = No_Index then | |
799 | return First (Object.Container.all); | |
d85fd922 | 800 | else |
e8bd500e | 801 | return Cursor'(Object.Container, Object.Index); |
a6dd3a54 | 802 | end if; |
a6dd3a54 ES |
803 | end First; |
804 | ||
1e194575 AC |
805 | ------------------- |
806 | -- First_Element -- | |
807 | ------------------- | |
808 | ||
809 | function First_Element (Container : Vector) return Element_Type is | |
810 | begin | |
811 | if Container.Last = No_Index then | |
812 | raise Constraint_Error with "Container is empty"; | |
d85fd922 AC |
813 | else |
814 | return Container.Elements (To_Array_Index (Index_Type'First)); | |
1e194575 | 815 | end if; |
1e194575 AC |
816 | end First_Element; |
817 | ||
818 | ----------------- | |
819 | -- First_Index -- | |
820 | ----------------- | |
821 | ||
822 | function First_Index (Container : Vector) return Index_Type is | |
823 | pragma Unreferenced (Container); | |
824 | begin | |
825 | return Index_Type'First; | |
826 | end First_Index; | |
827 | ||
828 | --------------------- | |
829 | -- Generic_Sorting -- | |
830 | --------------------- | |
831 | ||
832 | package body Generic_Sorting is | |
833 | ||
834 | --------------- | |
835 | -- Is_Sorted -- | |
836 | --------------- | |
837 | ||
838 | function Is_Sorted (Container : Vector) return Boolean is | |
839 | begin | |
840 | if Container.Last <= Index_Type'First then | |
841 | return True; | |
842 | end if; | |
843 | ||
844 | declare | |
845 | EA : Elements_Array renames Container.Elements; | |
846 | begin | |
847 | for J in 1 .. Container.Length - 1 loop | |
848 | if EA (J + 1) < EA (J) then | |
849 | return False; | |
850 | end if; | |
851 | end loop; | |
852 | end; | |
853 | ||
854 | return True; | |
855 | end Is_Sorted; | |
856 | ||
857 | ----------- | |
858 | -- Merge -- | |
859 | ----------- | |
860 | ||
861 | procedure Merge (Target, Source : in out Vector) is | |
862 | I, J : Count_Type; | |
863 | ||
864 | begin | |
4c9fe6c7 AC |
865 | |
866 | -- The semantics of Merge changed slightly per AI05-0021. It was | |
867 | -- originally the case that if Target and Source denoted the same | |
868 | -- container object, then the GNAT implementation of Merge did | |
869 | -- nothing. However, it was argued that RM05 did not precisely | |
870 | -- specify the semantics for this corner case. The decision of the | |
871 | -- ARG was that if Target and Source denote the same non-empty | |
872 | -- container object, then Program_Error is raised. | |
873 | ||
874 | if Source.Is_Empty then | |
1e194575 AC |
875 | return; |
876 | end if; | |
877 | ||
878 | if Target'Address = Source'Address then | |
4c9fe6c7 AC |
879 | raise Program_Error with |
880 | "Target and Source denote same non-empty container"; | |
1e194575 AC |
881 | end if; |
882 | ||
4c9fe6c7 AC |
883 | if Target.Is_Empty then |
884 | Move (Target => Target, Source => Source); | |
1e194575 AC |
885 | return; |
886 | end if; | |
887 | ||
888 | if Source.Busy > 0 then | |
889 | raise Program_Error with | |
890 | "attempt to tamper with cursors (vector is busy)"; | |
891 | end if; | |
892 | ||
893 | I := Target.Length; | |
894 | Target.Set_Length (I + Source.Length); | |
895 | ||
896 | declare | |
897 | TA : Elements_Array renames Target.Elements; | |
898 | SA : Elements_Array renames Source.Elements; | |
899 | ||
900 | begin | |
901 | J := Target.Length; | |
902 | while not Source.Is_Empty loop | |
903 | pragma Assert (Source.Length <= 1 | |
904 | or else not (SA (Source.Length) < | |
905 | SA (Source.Length - 1))); | |
906 | ||
907 | if I = 0 then | |
908 | TA (1 .. J) := SA (1 .. Source.Length); | |
909 | Source.Last := No_Index; | |
910 | return; | |
911 | end if; | |
912 | ||
913 | pragma Assert (I <= 1 | |
914 | or else not (TA (I) < TA (I - 1))); | |
915 | ||
916 | if SA (Source.Length) < TA (I) then | |
917 | TA (J) := TA (I); | |
918 | I := I - 1; | |
919 | ||
920 | else | |
921 | TA (J) := SA (Source.Length); | |
922 | Source.Last := Source.Last - 1; | |
923 | end if; | |
924 | ||
925 | J := J - 1; | |
926 | end loop; | |
927 | end; | |
928 | end Merge; | |
929 | ||
930 | ---------- | |
931 | -- Sort -- | |
932 | ---------- | |
933 | ||
b727a82b | 934 | procedure Sort (Container : in out Vector) is |
1e194575 AC |
935 | procedure Sort is |
936 | new Generic_Array_Sort | |
937 | (Index_Type => Count_Type, | |
938 | Element_Type => Element_Type, | |
939 | Array_Type => Elements_Array, | |
940 | "<" => "<"); | |
941 | ||
942 | begin | |
943 | if Container.Last <= Index_Type'First then | |
944 | return; | |
945 | end if; | |
946 | ||
b727a82b AC |
947 | -- The exception behavior for the vector container must match that |
948 | -- for the list container, so we check for cursor tampering here | |
949 | -- (which will catch more things) instead of for element tampering | |
950 | -- (which will catch fewer things). It's true that the elements of | |
951 | -- this vector container could be safely moved around while (say) an | |
952 | -- iteration is taking place (iteration only increments the busy | |
953 | -- counter), and so technically all we would need here is a test for | |
954 | -- element tampering (indicated by the lock counter), that's simply | |
955 | -- an artifact of our array-based implementation. Logically Sort | |
956 | -- requires a check for cursor tampering. | |
957 | ||
958 | if Container.Busy > 0 then | |
1e194575 | 959 | raise Program_Error with |
b727a82b | 960 | "attempt to tamper with cursors (vector is busy)"; |
1e194575 AC |
961 | end if; |
962 | ||
963 | Sort (Container.Elements (1 .. Container.Length)); | |
964 | end Sort; | |
965 | ||
966 | end Generic_Sorting; | |
967 | ||
968 | ----------------- | |
969 | -- Has_Element -- | |
970 | ----------------- | |
971 | ||
972 | function Has_Element (Position : Cursor) return Boolean is | |
973 | begin | |
974 | if Position.Container = null then | |
975 | return False; | |
976 | end if; | |
977 | ||
978 | return Position.Index <= Position.Container.Last; | |
979 | end Has_Element; | |
980 | ||
981 | ------------ | |
982 | -- Insert -- | |
983 | ------------ | |
984 | ||
985 | procedure Insert | |
986 | (Container : in out Vector; | |
987 | Before : Extended_Index; | |
988 | New_Item : Element_Type; | |
989 | Count : Count_Type := 1) | |
990 | is | |
991 | EA : Elements_Array renames Container.Elements; | |
992 | Old_Length : constant Count_Type := Container.Length; | |
993 | ||
994 | Max_Length : Count_Type'Base; -- determined from range of Index_Type | |
995 | New_Length : Count_Type'Base; -- sum of current length and Count | |
996 | ||
997 | Index : Index_Type'Base; -- scratch for intermediate values | |
998 | J : Count_Type'Base; -- scratch | |
999 | ||
1000 | begin | |
1001 | -- As a precondition on the generic actual Index_Type, the base type | |
1002 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
1003 | -- that Container.Last assumes when the vector is empty. However, we do | |
1004 | -- not allow that as the value for Index when specifying where the new | |
1005 | -- items should be inserted, so we must manually check. (That the user | |
1006 | -- is allowed to specify the value at all here is a consequence of the | |
1007 | -- declaration of the Extended_Index subtype, which includes the values | |
1008 | -- in the base range that immediately precede and immediately follow the | |
1009 | -- values in the Index_Type.) | |
1010 | ||
1011 | if Before < Index_Type'First then | |
1012 | raise Constraint_Error with | |
1013 | "Before index is out of range (too small)"; | |
1014 | end if; | |
1015 | ||
1016 | -- We do allow a value greater than Container.Last to be specified as | |
1017 | -- the Index, but only if it's immediately greater. This allows for the | |
1018 | -- case of appending items to the back end of the vector. (It is assumed | |
1019 | -- that specifying an index value greater than Last + 1 indicates some | |
1020 | -- deeper flaw in the caller's algorithm, so that case is treated as a | |
1021 | -- proper error.) | |
1022 | ||
1023 | if Before > Container.Last | |
1024 | and then Before > Container.Last + 1 | |
1025 | then | |
1026 | raise Constraint_Error with | |
1027 | "Before index is out of range (too large)"; | |
1028 | end if; | |
1029 | ||
1030 | -- We treat inserting 0 items into the container as a no-op, even when | |
1031 | -- the container is busy, so we simply return. | |
1032 | ||
1033 | if Count = 0 then | |
1034 | return; | |
1035 | end if; | |
1036 | ||
1037 | -- There are two constraints we need to satisfy. The first constraint is | |
1038 | -- that a container cannot have more than Count_Type'Last elements, so | |
1039 | -- we must check the sum of the current length and the insertion | |
1040 | -- count. Note that we cannot simply add these values, because of the | |
308e6f3a | 1041 | -- possibility of overflow. |
1e194575 AC |
1042 | |
1043 | if Old_Length > Count_Type'Last - Count then | |
1044 | raise Constraint_Error with "Count is out of range"; | |
1045 | end if; | |
1046 | ||
1047 | -- It is now safe compute the length of the new vector, without fear of | |
1048 | -- overflow. | |
1049 | ||
1050 | New_Length := Old_Length + Count; | |
1051 | ||
1052 | -- The second constraint is that the new Last index value cannot exceed | |
1053 | -- Index_Type'Last. In each branch below, we calculate the maximum | |
1054 | -- length (computed from the range of values in Index_Type), and then | |
1055 | -- compare the new length to the maximum length. If the new length is | |
1056 | -- acceptable, then we compute the new last index from that. | |
1057 | ||
1058 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
1059 | -- We have to handle the case when there might be more values in the | |
1060 | -- range of Index_Type than in the range of Count_Type. | |
1061 | ||
1062 | if Index_Type'First <= 0 then | |
1063 | -- We know that No_Index (the same as Index_Type'First - 1) is | |
1064 | -- less than 0, so it is safe to compute the following sum without | |
1065 | -- fear of overflow. | |
1066 | ||
1067 | Index := No_Index + Index_Type'Base (Count_Type'Last); | |
1068 | ||
1069 | if Index <= Index_Type'Last then | |
1070 | -- We have determined that range of Index_Type has at least as | |
1071 | -- many values as in Count_Type, so Count_Type'Last is the | |
1072 | -- maximum number of items that are allowed. | |
1073 | ||
1074 | Max_Length := Count_Type'Last; | |
1075 | ||
1076 | else | |
1077 | -- The range of Index_Type has fewer values than in Count_Type, | |
1078 | -- so the maximum number of items is computed from the range of | |
1079 | -- the Index_Type. | |
1080 | ||
1081 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1082 | end if; | |
1083 | ||
1084 | else | |
1085 | -- No_Index is equal or greater than 0, so we can safely compute | |
1086 | -- the difference without fear of overflow (which we would have to | |
1087 | -- worry about if No_Index were less than 0, but that case is | |
1088 | -- handled above). | |
1089 | ||
1090 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1091 | end if; | |
1092 | ||
1093 | elsif Index_Type'First <= 0 then | |
1094 | -- We know that No_Index (the same as Index_Type'First - 1) is less | |
1095 | -- than 0, so it is safe to compute the following sum without fear of | |
1096 | -- overflow. | |
1097 | ||
1098 | J := Count_Type'Base (No_Index) + Count_Type'Last; | |
1099 | ||
1100 | if J <= Count_Type'Base (Index_Type'Last) then | |
1101 | -- We have determined that range of Index_Type has at least as | |
1102 | -- many values as in Count_Type, so Count_Type'Last is the maximum | |
1103 | -- number of items that are allowed. | |
1104 | ||
1105 | Max_Length := Count_Type'Last; | |
1106 | ||
1107 | else | |
1108 | -- The range of Index_Type has fewer values than Count_Type does, | |
1109 | -- so the maximum number of items is computed from the range of | |
1110 | -- the Index_Type. | |
1111 | ||
1112 | Max_Length := | |
1113 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
1114 | end if; | |
1115 | ||
1116 | else | |
1117 | -- No_Index is equal or greater than 0, so we can safely compute the | |
1118 | -- difference without fear of overflow (which we would have to worry | |
1119 | -- about if No_Index were less than 0, but that case is handled | |
1120 | -- above). | |
1121 | ||
1122 | Max_Length := | |
1123 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
1124 | end if; | |
1125 | ||
1126 | -- We have just computed the maximum length (number of items). We must | |
1127 | -- now compare the requested length to the maximum length, as we do not | |
1128 | -- allow a vector expand beyond the maximum (because that would create | |
1129 | -- an internal array with a last index value greater than | |
1130 | -- Index_Type'Last, with no way to index those elements). | |
1131 | ||
1132 | if New_Length > Max_Length then | |
1133 | raise Constraint_Error with "Count is out of range"; | |
1134 | end if; | |
1135 | ||
1136 | -- The tampering bits exist to prevent an item from being harmfully | |
1137 | -- manipulated while it is being visited. Query, Update, and Iterate | |
1138 | -- increment the busy count on entry, and decrement the count on | |
1139 | -- exit. Insert checks the count to determine whether it is being called | |
1140 | -- while the associated callback procedure is executing. | |
1141 | ||
1142 | if Container.Busy > 0 then | |
1143 | raise Program_Error with | |
1144 | "attempt to tamper with cursors (vector is busy)"; | |
1145 | end if; | |
1146 | ||
1147 | if New_Length > Container.Capacity then | |
1148 | raise Capacity_Error with "New length is larger than capacity"; | |
1149 | end if; | |
1150 | ||
1151 | J := To_Array_Index (Before); | |
1152 | ||
1153 | if Before > Container.Last then | |
1154 | -- The new items are being appended to the vector, so no | |
1155 | -- sliding of existing elements is required. | |
1156 | ||
1157 | EA (J .. New_Length) := (others => New_Item); | |
1158 | ||
1159 | else | |
1160 | -- The new items are being inserted before some existing | |
1161 | -- elements, so we must slide the existing elements up to their | |
1162 | -- new home. | |
1163 | ||
1164 | EA (J + Count .. New_Length) := EA (J .. Old_Length); | |
1165 | EA (J .. J + Count - 1) := (others => New_Item); | |
1166 | end if; | |
1167 | ||
1168 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
1169 | Container.Last := No_Index + Index_Type'Base (New_Length); | |
1170 | ||
1171 | else | |
1172 | Container.Last := | |
1173 | Index_Type'Base (Count_Type'Base (No_Index) + New_Length); | |
1174 | end if; | |
1175 | end Insert; | |
1176 | ||
1177 | procedure Insert | |
1178 | (Container : in out Vector; | |
1179 | Before : Extended_Index; | |
1180 | New_Item : Vector) | |
1181 | is | |
1182 | N : constant Count_Type := Length (New_Item); | |
1183 | B : Count_Type; -- index Before converted to Count_Type | |
1184 | ||
1185 | begin | |
1186 | -- Use Insert_Space to create the "hole" (the destination slice) into | |
1187 | -- which we copy the source items. | |
1188 | ||
1189 | Insert_Space (Container, Before, Count => N); | |
1190 | ||
1191 | if N = 0 then | |
1192 | -- There's nothing else to do here (vetting of parameters was | |
1193 | -- performed already in Insert_Space), so we simply return. | |
1194 | ||
1195 | return; | |
1196 | end if; | |
1197 | ||
1198 | B := To_Array_Index (Before); | |
1199 | ||
1200 | if Container'Address /= New_Item'Address then | |
1201 | -- This is the simple case. New_Item denotes an object different | |
1202 | -- from Container, so there's nothing special we need to do to copy | |
1203 | -- the source items to their destination, because all of the source | |
1204 | -- items are contiguous. | |
1205 | ||
1206 | Container.Elements (B .. B + N - 1) := New_Item.Elements (1 .. N); | |
1207 | return; | |
1208 | end if; | |
1209 | ||
1210 | -- We refer to array index value Before + N - 1 as J. This is the last | |
1211 | -- index value of the destination slice. | |
1212 | ||
1213 | -- New_Item denotes the same object as Container, so an insertion has | |
1214 | -- potentially split the source items. The destination is always the | |
1215 | -- range [Before, J], but the source is [Index_Type'First, Before) and | |
1216 | -- (J, Container.Last]. We perform the copy in two steps, using each of | |
1217 | -- the two slices of the source items. | |
1218 | ||
1219 | declare | |
1220 | subtype Src_Index_Subtype is Count_Type'Base range 1 .. B - 1; | |
1221 | ||
1222 | Src : Elements_Array renames Container.Elements (Src_Index_Subtype); | |
1223 | ||
1224 | begin | |
1225 | -- We first copy the source items that precede the space we | |
1226 | -- inserted. (If Before equals Index_Type'First, then this first | |
1227 | -- source slice will be empty, which is harmless.) | |
1228 | ||
1229 | Container.Elements (B .. B + Src'Length - 1) := Src; | |
1230 | end; | |
1231 | ||
1232 | declare | |
1233 | subtype Src_Index_Subtype is Count_Type'Base range | |
1234 | B + N .. Container.Length; | |
1235 | ||
1236 | Src : Elements_Array renames Container.Elements (Src_Index_Subtype); | |
1237 | ||
1238 | begin | |
1239 | -- We next copy the source items that follow the space we inserted. | |
1240 | ||
1241 | Container.Elements (B + N - Src'Length .. B + N - 1) := Src; | |
1242 | end; | |
1243 | end Insert; | |
1244 | ||
1245 | procedure Insert | |
1246 | (Container : in out Vector; | |
1247 | Before : Cursor; | |
1248 | New_Item : Vector) | |
1249 | is | |
1250 | Index : Index_Type'Base; | |
1251 | ||
1252 | begin | |
1253 | if Before.Container /= null | |
1254 | and then Before.Container /= Container'Unchecked_Access | |
1255 | then | |
1256 | raise Program_Error with "Before cursor denotes wrong container"; | |
1257 | end if; | |
1258 | ||
1259 | if Is_Empty (New_Item) then | |
1260 | return; | |
1261 | end if; | |
1262 | ||
1263 | if Before.Container = null | |
1264 | or else Before.Index > Container.Last | |
1265 | then | |
1266 | if Container.Last = Index_Type'Last then | |
1267 | raise Constraint_Error with | |
1268 | "vector is already at its maximum length"; | |
1269 | end if; | |
1270 | ||
1271 | Index := Container.Last + 1; | |
1272 | ||
1273 | else | |
1274 | Index := Before.Index; | |
1275 | end if; | |
1276 | ||
1277 | Insert (Container, Index, New_Item); | |
1278 | end Insert; | |
1279 | ||
1280 | procedure Insert | |
1281 | (Container : in out Vector; | |
1282 | Before : Cursor; | |
1283 | New_Item : Vector; | |
1284 | Position : out Cursor) | |
1285 | is | |
1286 | Index : Index_Type'Base; | |
1287 | ||
1288 | begin | |
1289 | if Before.Container /= null | |
1290 | and then Before.Container /= Container'Unchecked_Access | |
1291 | then | |
1292 | raise Program_Error with "Before cursor denotes wrong container"; | |
1293 | end if; | |
1294 | ||
1295 | if Is_Empty (New_Item) then | |
1296 | if Before.Container = null | |
1297 | or else Before.Index > Container.Last | |
1298 | then | |
1299 | Position := No_Element; | |
1300 | else | |
1301 | Position := (Container'Unchecked_Access, Before.Index); | |
1302 | end if; | |
1303 | ||
1304 | return; | |
1305 | end if; | |
1306 | ||
1307 | if Before.Container = null | |
1308 | or else Before.Index > Container.Last | |
1309 | then | |
1310 | if Container.Last = Index_Type'Last then | |
1311 | raise Constraint_Error with | |
1312 | "vector is already at its maximum length"; | |
1313 | end if; | |
1314 | ||
1315 | Index := Container.Last + 1; | |
1316 | ||
1317 | else | |
1318 | Index := Before.Index; | |
1319 | end if; | |
1320 | ||
1321 | Insert (Container, Index, New_Item); | |
1322 | ||
1323 | Position := Cursor'(Container'Unchecked_Access, Index); | |
1324 | end Insert; | |
1325 | ||
1326 | procedure Insert | |
1327 | (Container : in out Vector; | |
1328 | Before : Cursor; | |
1329 | New_Item : Element_Type; | |
1330 | Count : Count_Type := 1) | |
1331 | is | |
1332 | Index : Index_Type'Base; | |
1333 | ||
1334 | begin | |
1335 | if Before.Container /= null | |
1336 | and then Before.Container /= Container'Unchecked_Access | |
1337 | then | |
1338 | raise Program_Error with "Before cursor denotes wrong container"; | |
1339 | end if; | |
1340 | ||
1341 | if Count = 0 then | |
1342 | return; | |
1343 | end if; | |
1344 | ||
1345 | if Before.Container = null | |
1346 | or else Before.Index > Container.Last | |
1347 | then | |
1348 | if Container.Last = Index_Type'Last then | |
1349 | raise Constraint_Error with | |
1350 | "vector is already at its maximum length"; | |
1351 | end if; | |
1352 | ||
1353 | Index := Container.Last + 1; | |
1354 | ||
1355 | else | |
1356 | Index := Before.Index; | |
1357 | end if; | |
1358 | ||
1359 | Insert (Container, Index, New_Item, Count); | |
1360 | end Insert; | |
1361 | ||
1362 | procedure Insert | |
1363 | (Container : in out Vector; | |
1364 | Before : Cursor; | |
1365 | New_Item : Element_Type; | |
1366 | Position : out Cursor; | |
1367 | Count : Count_Type := 1) | |
1368 | is | |
1369 | Index : Index_Type'Base; | |
1370 | ||
1371 | begin | |
1372 | if Before.Container /= null | |
1373 | and then Before.Container /= Container'Unchecked_Access | |
1374 | then | |
1375 | raise Program_Error with "Before cursor denotes wrong container"; | |
1376 | end if; | |
1377 | ||
1378 | if Count = 0 then | |
1379 | if Before.Container = null | |
1380 | or else Before.Index > Container.Last | |
1381 | then | |
1382 | Position := No_Element; | |
1383 | else | |
1384 | Position := (Container'Unchecked_Access, Before.Index); | |
1385 | end if; | |
1386 | ||
1387 | return; | |
1388 | end if; | |
1389 | ||
1390 | if Before.Container = null | |
1391 | or else Before.Index > Container.Last | |
1392 | then | |
1393 | if Container.Last = Index_Type'Last then | |
1394 | raise Constraint_Error with | |
1395 | "vector is already at its maximum length"; | |
1396 | end if; | |
1397 | ||
1398 | Index := Container.Last + 1; | |
1399 | ||
1400 | else | |
1401 | Index := Before.Index; | |
1402 | end if; | |
1403 | ||
1404 | Insert (Container, Index, New_Item, Count); | |
1405 | ||
1406 | Position := Cursor'(Container'Unchecked_Access, Index); | |
1407 | end Insert; | |
1408 | ||
1409 | procedure Insert | |
1410 | (Container : in out Vector; | |
1411 | Before : Extended_Index; | |
1412 | Count : Count_Type := 1) | |
1413 | is | |
1414 | New_Item : Element_Type; -- Default-initialized value | |
1415 | pragma Warnings (Off, New_Item); | |
1416 | ||
1417 | begin | |
1418 | Insert (Container, Before, New_Item, Count); | |
1419 | end Insert; | |
1420 | ||
1421 | procedure Insert | |
1422 | (Container : in out Vector; | |
1423 | Before : Cursor; | |
1424 | Position : out Cursor; | |
1425 | Count : Count_Type := 1) | |
1426 | is | |
1427 | New_Item : Element_Type; -- Default-initialized value | |
1428 | pragma Warnings (Off, New_Item); | |
1429 | ||
1430 | begin | |
1431 | Insert (Container, Before, New_Item, Position, Count); | |
1432 | end Insert; | |
1433 | ||
1434 | ------------------ | |
1435 | -- Insert_Space -- | |
1436 | ------------------ | |
1437 | ||
1438 | procedure Insert_Space | |
1439 | (Container : in out Vector; | |
1440 | Before : Extended_Index; | |
1441 | Count : Count_Type := 1) | |
1442 | is | |
1443 | EA : Elements_Array renames Container.Elements; | |
1444 | Old_Length : constant Count_Type := Container.Length; | |
1445 | ||
1446 | Max_Length : Count_Type'Base; -- determined from range of Index_Type | |
1447 | New_Length : Count_Type'Base; -- sum of current length and Count | |
1448 | ||
1449 | Index : Index_Type'Base; -- scratch for intermediate values | |
1450 | J : Count_Type'Base; -- scratch | |
1451 | ||
1452 | begin | |
1453 | -- As a precondition on the generic actual Index_Type, the base type | |
1454 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
1455 | -- that Container.Last assumes when the vector is empty. However, we do | |
1456 | -- not allow that as the value for Index when specifying where the new | |
1457 | -- items should be inserted, so we must manually check. (That the user | |
1458 | -- is allowed to specify the value at all here is a consequence of the | |
1459 | -- declaration of the Extended_Index subtype, which includes the values | |
1460 | -- in the base range that immediately precede and immediately follow the | |
1461 | -- values in the Index_Type.) | |
1462 | ||
1463 | if Before < Index_Type'First then | |
1464 | raise Constraint_Error with | |
1465 | "Before index is out of range (too small)"; | |
1466 | end if; | |
1467 | ||
1468 | -- We do allow a value greater than Container.Last to be specified as | |
1469 | -- the Index, but only if it's immediately greater. This allows for the | |
1470 | -- case of appending items to the back end of the vector. (It is assumed | |
1471 | -- that specifying an index value greater than Last + 1 indicates some | |
1472 | -- deeper flaw in the caller's algorithm, so that case is treated as a | |
1473 | -- proper error.) | |
1474 | ||
1475 | if Before > Container.Last | |
1476 | and then Before > Container.Last + 1 | |
1477 | then | |
1478 | raise Constraint_Error with | |
1479 | "Before index is out of range (too large)"; | |
1480 | end if; | |
1481 | ||
1482 | -- We treat inserting 0 items into the container as a no-op, even when | |
1483 | -- the container is busy, so we simply return. | |
1484 | ||
1485 | if Count = 0 then | |
1486 | return; | |
1487 | end if; | |
1488 | ||
1489 | -- There are two constraints we need to satisfy. The first constraint is | |
1490 | -- that a container cannot have more than Count_Type'Last elements, so | |
0b5b2bbc AC |
1491 | -- we must check the sum of the current length and the insertion count. |
1492 | -- Note that we cannot simply add these values, because of the | |
308e6f3a | 1493 | -- possibility of overflow. |
1e194575 AC |
1494 | |
1495 | if Old_Length > Count_Type'Last - Count then | |
1496 | raise Constraint_Error with "Count is out of range"; | |
1497 | end if; | |
1498 | ||
1499 | -- It is now safe compute the length of the new vector, without fear of | |
1500 | -- overflow. | |
1501 | ||
1502 | New_Length := Old_Length + Count; | |
1503 | ||
1504 | -- The second constraint is that the new Last index value cannot exceed | |
1505 | -- Index_Type'Last. In each branch below, we calculate the maximum | |
1506 | -- length (computed from the range of values in Index_Type), and then | |
1507 | -- compare the new length to the maximum length. If the new length is | |
1508 | -- acceptable, then we compute the new last index from that. | |
1509 | ||
1510 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
1511 | -- We have to handle the case when there might be more values in the | |
1512 | -- range of Index_Type than in the range of Count_Type. | |
1513 | ||
1514 | if Index_Type'First <= 0 then | |
1515 | -- We know that No_Index (the same as Index_Type'First - 1) is | |
1516 | -- less than 0, so it is safe to compute the following sum without | |
1517 | -- fear of overflow. | |
1518 | ||
1519 | Index := No_Index + Index_Type'Base (Count_Type'Last); | |
1520 | ||
1521 | if Index <= Index_Type'Last then | |
1522 | -- We have determined that range of Index_Type has at least as | |
1523 | -- many values as in Count_Type, so Count_Type'Last is the | |
1524 | -- maximum number of items that are allowed. | |
1525 | ||
1526 | Max_Length := Count_Type'Last; | |
1527 | ||
1528 | else | |
1529 | -- The range of Index_Type has fewer values than in Count_Type, | |
1530 | -- so the maximum number of items is computed from the range of | |
1531 | -- the Index_Type. | |
1532 | ||
1533 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1534 | end if; | |
1535 | ||
1536 | else | |
1537 | -- No_Index is equal or greater than 0, so we can safely compute | |
1538 | -- the difference without fear of overflow (which we would have to | |
1539 | -- worry about if No_Index were less than 0, but that case is | |
1540 | -- handled above). | |
1541 | ||
1542 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1543 | end if; | |
1544 | ||
1545 | elsif Index_Type'First <= 0 then | |
1546 | -- We know that No_Index (the same as Index_Type'First - 1) is less | |
1547 | -- than 0, so it is safe to compute the following sum without fear of | |
1548 | -- overflow. | |
1549 | ||
1550 | J := Count_Type'Base (No_Index) + Count_Type'Last; | |
1551 | ||
1552 | if J <= Count_Type'Base (Index_Type'Last) then | |
1553 | -- We have determined that range of Index_Type has at least as | |
1554 | -- many values as in Count_Type, so Count_Type'Last is the maximum | |
1555 | -- number of items that are allowed. | |
1556 | ||
1557 | Max_Length := Count_Type'Last; | |
1558 | ||
1559 | else | |
1560 | -- The range of Index_Type has fewer values than Count_Type does, | |
1561 | -- so the maximum number of items is computed from the range of | |
1562 | -- the Index_Type. | |
1563 | ||
1564 | Max_Length := | |
1565 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
1566 | end if; | |
1567 | ||
1568 | else | |
1569 | -- No_Index is equal or greater than 0, so we can safely compute the | |
1570 | -- difference without fear of overflow (which we would have to worry | |
1571 | -- about if No_Index were less than 0, but that case is handled | |
1572 | -- above). | |
1573 | ||
1574 | Max_Length := | |
1575 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
1576 | end if; | |
1577 | ||
1578 | -- We have just computed the maximum length (number of items). We must | |
1579 | -- now compare the requested length to the maximum length, as we do not | |
1580 | -- allow a vector expand beyond the maximum (because that would create | |
1581 | -- an internal array with a last index value greater than | |
1582 | -- Index_Type'Last, with no way to index those elements). | |
1583 | ||
1584 | if New_Length > Max_Length then | |
1585 | raise Constraint_Error with "Count is out of range"; | |
1586 | end if; | |
1587 | ||
1588 | -- The tampering bits exist to prevent an item from being harmfully | |
1589 | -- manipulated while it is being visited. Query, Update, and Iterate | |
1590 | -- increment the busy count on entry, and decrement the count on | |
1591 | -- exit. Insert checks the count to determine whether it is being called | |
1592 | -- while the associated callback procedure is executing. | |
1593 | ||
1594 | if Container.Busy > 0 then | |
1595 | raise Program_Error with | |
1596 | "attempt to tamper with cursors (vector is busy)"; | |
1597 | end if; | |
1598 | ||
1599 | -- An internal array has already been allocated, so we need to check | |
1600 | -- whether there is enough unused storage for the new items. | |
1601 | ||
1602 | if New_Length > Container.Capacity then | |
1603 | raise Capacity_Error with "New length is larger than capacity"; | |
1604 | end if; | |
1605 | ||
1606 | -- In this case, we're inserting space into a vector that has already | |
1607 | -- allocated an internal array, and the existing array has enough | |
1608 | -- unused storage for the new items. | |
1609 | ||
1610 | if Before <= Container.Last then | |
1611 | -- The space is being inserted before some existing elements, | |
1612 | -- so we must slide the existing elements up to their new home. | |
1613 | ||
1614 | J := To_Array_Index (Before); | |
1615 | EA (J + Count .. New_Length) := EA (J .. Old_Length); | |
1616 | end if; | |
1617 | ||
1618 | -- New_Last is the last index value of the items in the container after | |
1619 | -- insertion. Use the wider of Index_Type'Base and Count_Type'Base to | |
1620 | -- compute its value from the New_Length. | |
1621 | ||
1622 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
1623 | Container.Last := No_Index + Index_Type'Base (New_Length); | |
1624 | ||
1625 | else | |
1626 | Container.Last := | |
1627 | Index_Type'Base (Count_Type'Base (No_Index) + New_Length); | |
1628 | end if; | |
1629 | end Insert_Space; | |
1630 | ||
1631 | procedure Insert_Space | |
1632 | (Container : in out Vector; | |
1633 | Before : Cursor; | |
1634 | Position : out Cursor; | |
1635 | Count : Count_Type := 1) | |
1636 | is | |
1637 | Index : Index_Type'Base; | |
1638 | ||
1639 | begin | |
1640 | if Before.Container /= null | |
1641 | and then Before.Container /= Container'Unchecked_Access | |
1642 | then | |
1643 | raise Program_Error with "Before cursor denotes wrong container"; | |
1644 | end if; | |
1645 | ||
1646 | if Count = 0 then | |
1647 | if Before.Container = null | |
1648 | or else Before.Index > Container.Last | |
1649 | then | |
1650 | Position := No_Element; | |
1651 | else | |
1652 | Position := (Container'Unchecked_Access, Before.Index); | |
1653 | end if; | |
1654 | ||
1655 | return; | |
1656 | end if; | |
1657 | ||
1658 | if Before.Container = null | |
1659 | or else Before.Index > Container.Last | |
1660 | then | |
1661 | if Container.Last = Index_Type'Last then | |
1662 | raise Constraint_Error with | |
1663 | "vector is already at its maximum length"; | |
1664 | end if; | |
1665 | ||
1666 | Index := Container.Last + 1; | |
1667 | ||
1668 | else | |
1669 | Index := Before.Index; | |
1670 | end if; | |
1671 | ||
1672 | Insert_Space (Container, Index, Count => Count); | |
1673 | ||
1674 | Position := Cursor'(Container'Unchecked_Access, Index); | |
1675 | end Insert_Space; | |
1676 | ||
1677 | -------------- | |
1678 | -- Is_Empty -- | |
1679 | -------------- | |
1680 | ||
1681 | function Is_Empty (Container : Vector) return Boolean is | |
1682 | begin | |
1683 | return Container.Last < Index_Type'First; | |
1684 | end Is_Empty; | |
1685 | ||
1686 | ------------- | |
1687 | -- Iterate -- | |
1688 | ------------- | |
1689 | ||
1690 | procedure Iterate | |
1691 | (Container : Vector; | |
1692 | Process : not null access procedure (Position : Cursor)) | |
1693 | is | |
ef992452 | 1694 | B : Natural renames Container'Unrestricted_Access.all.Busy; |
1e194575 AC |
1695 | |
1696 | begin | |
1697 | B := B + 1; | |
1698 | ||
1699 | begin | |
1700 | for Indx in Index_Type'First .. Container.Last loop | |
1701 | Process (Cursor'(Container'Unrestricted_Access, Indx)); | |
1702 | end loop; | |
1703 | exception | |
1704 | when others => | |
1705 | B := B - 1; | |
1706 | raise; | |
1707 | end; | |
1708 | ||
1709 | B := B - 1; | |
1710 | end Iterate; | |
1711 | ||
d85fd922 AC |
1712 | function Iterate |
1713 | (Container : Vector) | |
a6dd3a54 ES |
1714 | return Vector_Iterator_Interfaces.Reversible_Iterator'Class |
1715 | is | |
e8bd500e AC |
1716 | V : constant Vector_Access := Container'Unrestricted_Access; |
1717 | B : Natural renames V.Busy; | |
1718 | ||
a6dd3a54 | 1719 | begin |
e8bd500e AC |
1720 | -- The value of its Index component influences the behavior of the First |
1721 | -- and Last selector functions of the iterator object. When the Index | |
1722 | -- component is No_Index (as is the case here), this means the iterator | |
1723 | -- object was constructed without a start expression. This is a complete | |
1724 | -- iterator, meaning that the iteration starts from the (logical) | |
1725 | -- beginning of the sequence of items. | |
1726 | ||
1727 | -- Note: For a forward iterator, Container.First is the beginning, and | |
1728 | -- for a reverse iterator, Container.Last is the beginning. | |
1729 | ||
ef992452 | 1730 | return It : constant Iterator := |
e8bd500e AC |
1731 | (Limited_Controlled with |
1732 | Container => V, | |
1733 | Index => No_Index) | |
ef992452 AC |
1734 | do |
1735 | B := B + 1; | |
1736 | end return; | |
a6dd3a54 ES |
1737 | end Iterate; |
1738 | ||
d85fd922 AC |
1739 | function Iterate |
1740 | (Container : Vector; | |
1741 | Start : Cursor) | |
e8bd500e | 1742 | return Vector_Iterator_Interfaces.Reversible_Iterator'Class |
a6dd3a54 | 1743 | is |
e8bd500e AC |
1744 | V : constant Vector_Access := Container'Unrestricted_Access; |
1745 | B : Natural renames V.Busy; | |
1746 | ||
a6dd3a54 | 1747 | begin |
e8bd500e AC |
1748 | -- It was formerly the case that when Start = No_Element, the partial |
1749 | -- iterator was defined to behave the same as for a complete iterator, | |
1750 | -- and iterate over the entire sequence of items. However, those | |
1751 | -- semantics were unintuitive and arguably error-prone (it is too easy | |
1752 | -- to accidentally create an endless loop), and so they were changed, | |
1753 | -- per the ARG meeting in Denver on 2011/11. However, there was no | |
1754 | -- consensus about what positive meaning this corner case should have, | |
1755 | -- and so it was decided to simply raise an exception. This does imply, | |
1756 | -- however, that it is not possible to use a partial iterator to specify | |
1757 | -- an empty sequence of items. | |
1758 | ||
1759 | if Start.Container = null then | |
1760 | raise Constraint_Error with | |
1761 | "Start position for iterator equals No_Element"; | |
1762 | end if; | |
1763 | ||
1764 | if Start.Container /= V then | |
1765 | raise Program_Error with | |
1766 | "Start cursor of Iterate designates wrong vector"; | |
1767 | end if; | |
1768 | ||
1769 | if Start.Index > V.Last then | |
1770 | raise Constraint_Error with | |
1771 | "Start position for iterator equals No_Element"; | |
1772 | end if; | |
1773 | ||
1774 | -- The value of its Index component influences the behavior of the First | |
1775 | -- and Last selector functions of the iterator object. When the Index | |
1776 | -- component is not No_Index (as is the case here), it means that this | |
1777 | -- is a partial iteration, over a subset of the complete sequence of | |
1778 | -- items. The iterator object was constructed with a start expression, | |
1779 | -- indicating the position from which the iteration begins. Note that | |
1780 | -- the start position has the same value irrespective of whether this is | |
1781 | -- a forward or reverse iteration. | |
1782 | ||
ef992452 | 1783 | return It : constant Iterator := |
e8bd500e AC |
1784 | (Limited_Controlled with |
1785 | Container => V, | |
1786 | Index => Start.Index) | |
ef992452 AC |
1787 | do |
1788 | B := B + 1; | |
1789 | end return; | |
a6dd3a54 ES |
1790 | end Iterate; |
1791 | ||
1e194575 AC |
1792 | ---------- |
1793 | -- Last -- | |
1794 | ---------- | |
1795 | ||
1796 | function Last (Container : Vector) return Cursor is | |
1797 | begin | |
1798 | if Is_Empty (Container) then | |
1799 | return No_Element; | |
d85fd922 AC |
1800 | else |
1801 | return (Container'Unrestricted_Access, Container.Last); | |
1e194575 | 1802 | end if; |
1e194575 AC |
1803 | end Last; |
1804 | ||
a6dd3a54 ES |
1805 | function Last (Object : Iterator) return Cursor is |
1806 | begin | |
e8bd500e AC |
1807 | -- The value of the iterator object's Index component influences the |
1808 | -- behavior of the Last (and First) selector function. | |
1809 | ||
1810 | -- When the Index component is No_Index, this means the iterator object | |
1811 | -- was constructed without a start expression, in which case the | |
1812 | -- (reverse) iteration starts from the (logical) beginning of the entire | |
1813 | -- sequence (corresponding to Container.Last, for a reverse iterator). | |
1814 | ||
1815 | -- Otherwise, this is iteration over a partial sequence of items. When | |
1816 | -- the Index component is not No_Index, the iterator object was | |
1817 | -- constructed with a start expression, that specifies the position from | |
1818 | -- which the (reverse) partial iteration begins. | |
1819 | ||
1820 | if Object.Index = No_Index then | |
1821 | return Last (Object.Container.all); | |
d85fd922 | 1822 | else |
e8bd500e | 1823 | return Cursor'(Object.Container, Object.Index); |
a6dd3a54 | 1824 | end if; |
a6dd3a54 ES |
1825 | end Last; |
1826 | ||
1e194575 AC |
1827 | ------------------ |
1828 | -- Last_Element -- | |
1829 | ------------------ | |
1830 | ||
1831 | function Last_Element (Container : Vector) return Element_Type is | |
1832 | begin | |
1833 | if Container.Last = No_Index then | |
1834 | raise Constraint_Error with "Container is empty"; | |
d85fd922 AC |
1835 | else |
1836 | return Container.Elements (Container.Length); | |
1e194575 | 1837 | end if; |
1e194575 AC |
1838 | end Last_Element; |
1839 | ||
1840 | ---------------- | |
1841 | -- Last_Index -- | |
1842 | ---------------- | |
1843 | ||
1844 | function Last_Index (Container : Vector) return Extended_Index is | |
1845 | begin | |
1846 | return Container.Last; | |
1847 | end Last_Index; | |
1848 | ||
1849 | ------------ | |
1850 | -- Length -- | |
1851 | ------------ | |
1852 | ||
1853 | function Length (Container : Vector) return Count_Type is | |
1854 | L : constant Index_Type'Base := Container.Last; | |
1855 | F : constant Index_Type := Index_Type'First; | |
1856 | ||
1857 | begin | |
1858 | -- The base range of the index type (Index_Type'Base) might not include | |
1859 | -- all values for length (Count_Type). Contrariwise, the index type | |
1860 | -- might include values outside the range of length. Hence we use | |
1861 | -- whatever type is wider for intermediate values when calculating | |
1862 | -- length. Note that no matter what the index type is, the maximum | |
1863 | -- length to which a vector is allowed to grow is always the minimum | |
1864 | -- of Count_Type'Last and (IT'Last - IT'First + 1). | |
1865 | ||
1866 | -- For example, an Index_Type with range -127 .. 127 is only guaranteed | |
1867 | -- to have a base range of -128 .. 127, but the corresponding vector | |
1868 | -- would have lengths in the range 0 .. 255. In this case we would need | |
1869 | -- to use Count_Type'Base for intermediate values. | |
1870 | ||
1871 | -- Another case would be the index range -2**63 + 1 .. -2**63 + 10. The | |
1872 | -- vector would have a maximum length of 10, but the index values lie | |
1873 | -- outside the range of Count_Type (which is only 32 bits). In this | |
1874 | -- case we would need to use Index_Type'Base for intermediate values. | |
1875 | ||
1876 | if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then | |
1877 | return Count_Type'Base (L) - Count_Type'Base (F) + 1; | |
1878 | else | |
1879 | return Count_Type (L - F + 1); | |
1880 | end if; | |
1881 | end Length; | |
1882 | ||
1883 | ---------- | |
1884 | -- Move -- | |
1885 | ---------- | |
1886 | ||
1887 | procedure Move | |
1888 | (Target : in out Vector; | |
1889 | Source : in out Vector) | |
1890 | is | |
1891 | begin | |
1892 | if Target'Address = Source'Address then | |
1893 | return; | |
1894 | end if; | |
1895 | ||
1896 | if Target.Capacity < Source.Length then | |
1897 | raise Capacity_Error -- ??? | |
1898 | with "Target capacity is less than Source length"; | |
1899 | end if; | |
1900 | ||
1901 | if Target.Busy > 0 then | |
1902 | raise Program_Error with | |
1903 | "attempt to tamper with cursors (Target is busy)"; | |
1904 | end if; | |
1905 | ||
1906 | if Source.Busy > 0 then | |
1907 | raise Program_Error with | |
1908 | "attempt to tamper with cursors (Source is busy)"; | |
1909 | end if; | |
1910 | ||
e47e21c1 AC |
1911 | -- Clear Target now, in case element assignment fails |
1912 | ||
1e194575 AC |
1913 | Target.Last := No_Index; |
1914 | ||
1915 | Target.Elements (1 .. Source.Length) := | |
1916 | Source.Elements (1 .. Source.Length); | |
1917 | ||
1918 | Target.Last := Source.Last; | |
1919 | Source.Last := No_Index; | |
1920 | end Move; | |
1921 | ||
1922 | ---------- | |
1923 | -- Next -- | |
1924 | ---------- | |
1925 | ||
1926 | function Next (Position : Cursor) return Cursor is | |
1927 | begin | |
1928 | if Position.Container = null then | |
1929 | return No_Element; | |
1930 | end if; | |
1931 | ||
1932 | if Position.Index < Position.Container.Last then | |
1933 | return (Position.Container, Position.Index + 1); | |
1934 | end if; | |
1935 | ||
1936 | return No_Element; | |
1937 | end Next; | |
1938 | ||
a6dd3a54 ES |
1939 | function Next (Object : Iterator; Position : Cursor) return Cursor is |
1940 | begin | |
e8bd500e AC |
1941 | if Position.Container = null then |
1942 | return No_Element; | |
a6dd3a54 | 1943 | end if; |
e8bd500e AC |
1944 | |
1945 | if Position.Container /= Object.Container then | |
1946 | raise Program_Error with | |
1947 | "Position cursor of Next designates wrong vector"; | |
1948 | end if; | |
1949 | ||
1950 | return Next (Position); | |
a6dd3a54 | 1951 | end Next; |
1e194575 AC |
1952 | |
1953 | procedure Next (Position : in out Cursor) is | |
1954 | begin | |
1955 | if Position.Container = null then | |
1956 | return; | |
1957 | end if; | |
1958 | ||
1959 | if Position.Index < Position.Container.Last then | |
1960 | Position.Index := Position.Index + 1; | |
1961 | else | |
1962 | Position := No_Element; | |
1963 | end if; | |
1964 | end Next; | |
1965 | ||
1966 | ------------- | |
1967 | -- Prepend -- | |
1968 | ------------- | |
1969 | ||
1970 | procedure Prepend (Container : in out Vector; New_Item : Vector) is | |
1971 | begin | |
1972 | Insert (Container, Index_Type'First, New_Item); | |
1973 | end Prepend; | |
1974 | ||
1975 | procedure Prepend | |
1976 | (Container : in out Vector; | |
1977 | New_Item : Element_Type; | |
1978 | Count : Count_Type := 1) | |
1979 | is | |
1980 | begin | |
1981 | Insert (Container, | |
1982 | Index_Type'First, | |
1983 | New_Item, | |
1984 | Count); | |
1985 | end Prepend; | |
1986 | ||
1987 | -------------- | |
1988 | -- Previous -- | |
1989 | -------------- | |
1990 | ||
1991 | procedure Previous (Position : in out Cursor) is | |
1992 | begin | |
1993 | if Position.Container = null then | |
1994 | return; | |
1995 | end if; | |
1996 | ||
1997 | if Position.Index > Index_Type'First then | |
1998 | Position.Index := Position.Index - 1; | |
1999 | else | |
2000 | Position := No_Element; | |
2001 | end if; | |
2002 | end Previous; | |
2003 | ||
2004 | function Previous (Position : Cursor) return Cursor is | |
2005 | begin | |
2006 | if Position.Container = null then | |
2007 | return No_Element; | |
2008 | end if; | |
2009 | ||
2010 | if Position.Index > Index_Type'First then | |
2011 | return (Position.Container, Position.Index - 1); | |
2012 | end if; | |
2013 | ||
2014 | return No_Element; | |
2015 | end Previous; | |
2016 | ||
a6dd3a54 ES |
2017 | function Previous (Object : Iterator; Position : Cursor) return Cursor is |
2018 | begin | |
e8bd500e | 2019 | if Position.Container = null then |
a6dd3a54 ES |
2020 | return No_Element; |
2021 | end if; | |
e8bd500e AC |
2022 | |
2023 | if Position.Container /= Object.Container then | |
2024 | raise Program_Error with | |
2025 | "Position cursor of Previous designates wrong vector"; | |
2026 | end if; | |
2027 | ||
2028 | return Previous (Position); | |
a6dd3a54 ES |
2029 | end Previous; |
2030 | ||
1e194575 AC |
2031 | ------------------- |
2032 | -- Query_Element -- | |
2033 | ------------------- | |
2034 | ||
2035 | procedure Query_Element | |
2036 | (Container : Vector; | |
2037 | Index : Index_Type; | |
2038 | Process : not null access procedure (Element : Element_Type)) | |
2039 | is | |
2040 | V : Vector renames Container'Unrestricted_Access.all; | |
2041 | B : Natural renames V.Busy; | |
2042 | L : Natural renames V.Lock; | |
2043 | ||
2044 | begin | |
2045 | if Index > Container.Last then | |
2046 | raise Constraint_Error with "Index is out of range"; | |
2047 | end if; | |
2048 | ||
2049 | B := B + 1; | |
2050 | L := L + 1; | |
2051 | ||
2052 | begin | |
2053 | Process (V.Elements (To_Array_Index (Index))); | |
2054 | exception | |
2055 | when others => | |
2056 | L := L - 1; | |
2057 | B := B - 1; | |
2058 | raise; | |
2059 | end; | |
2060 | ||
2061 | L := L - 1; | |
2062 | B := B - 1; | |
2063 | end Query_Element; | |
2064 | ||
2065 | procedure Query_Element | |
2066 | (Position : Cursor; | |
2067 | Process : not null access procedure (Element : Element_Type)) | |
2068 | is | |
2069 | begin | |
2070 | if Position.Container = null then | |
2071 | raise Constraint_Error with "Position cursor has no element"; | |
2072 | end if; | |
2073 | ||
2074 | Query_Element (Position.Container.all, Position.Index, Process); | |
2075 | end Query_Element; | |
2076 | ||
2077 | ---------- | |
2078 | -- Read -- | |
2079 | ---------- | |
2080 | ||
2081 | procedure Read | |
2082 | (Stream : not null access Root_Stream_Type'Class; | |
2083 | Container : out Vector) | |
2084 | is | |
2085 | Length : Count_Type'Base; | |
2086 | Last : Index_Type'Base := No_Index; | |
2087 | ||
2088 | begin | |
2089 | Clear (Container); | |
2090 | ||
2091 | Count_Type'Base'Read (Stream, Length); | |
2092 | ||
2093 | Reserve_Capacity (Container, Capacity => Length); | |
2094 | ||
2095 | for Idx in Count_Type range 1 .. Length loop | |
2096 | Last := Last + 1; | |
2097 | Element_Type'Read (Stream, Container.Elements (Idx)); | |
2098 | Container.Last := Last; | |
2099 | end loop; | |
2100 | end Read; | |
2101 | ||
2102 | procedure Read | |
2103 | (Stream : not null access Root_Stream_Type'Class; | |
2104 | Position : out Cursor) | |
2105 | is | |
2106 | begin | |
2107 | raise Program_Error with "attempt to stream vector cursor"; | |
2108 | end Read; | |
2109 | ||
a6dd3a54 ES |
2110 | procedure Read |
2111 | (Stream : not null access Root_Stream_Type'Class; | |
2112 | Item : out Reference_Type) | |
2113 | is | |
2114 | begin | |
2115 | raise Program_Error with "attempt to stream reference"; | |
2116 | end Read; | |
2117 | ||
2118 | procedure Read | |
2119 | (Stream : not null access Root_Stream_Type'Class; | |
2120 | Item : out Constant_Reference_Type) | |
2121 | is | |
2122 | begin | |
2123 | raise Program_Error with "attempt to stream reference"; | |
2124 | end Read; | |
2125 | ||
2126 | --------------- | |
2127 | -- Reference -- | |
2128 | --------------- | |
2129 | ||
c9423ca3 AC |
2130 | function Reference |
2131 | (Container : aliased in out Vector; | |
2132 | Position : Cursor) return Reference_Type | |
e47e21c1 | 2133 | is |
a6dd3a54 | 2134 | begin |
a6dd3a54 ES |
2135 | if Position.Container = null then |
2136 | raise Constraint_Error with "Position cursor has no element"; | |
2137 | end if; | |
2138 | ||
c9423ca3 AC |
2139 | if Position.Container /= Container'Unrestricted_Access then |
2140 | raise Program_Error with "Position cursor denotes wrong container"; | |
a6dd3a54 ES |
2141 | end if; |
2142 | ||
2143 | if Position.Index > Position.Container.Last then | |
2144 | raise Constraint_Error with "Position cursor is out of range"; | |
2145 | end if; | |
2146 | ||
c9423ca3 AC |
2147 | declare |
2148 | A : Elements_Array renames Container.Elements; | |
2149 | I : constant Count_Type := To_Array_Index (Position.Index); | |
2150 | begin | |
2151 | return (Element => A (I)'Access); | |
2152 | end; | |
a6dd3a54 ES |
2153 | end Reference; |
2154 | ||
e47e21c1 | 2155 | function Reference |
c9423ca3 AC |
2156 | (Container : aliased in out Vector; |
2157 | Index : Index_Type) return Reference_Type | |
e47e21c1 | 2158 | is |
a6dd3a54 | 2159 | begin |
c9423ca3 | 2160 | if Index > Container.Last then |
a6dd3a54 ES |
2161 | raise Constraint_Error with "Index is out of range"; |
2162 | end if; | |
c9423ca3 AC |
2163 | |
2164 | declare | |
2165 | A : Elements_Array renames Container.Elements; | |
2166 | I : constant Count_Type := To_Array_Index (Index); | |
2167 | begin | |
2168 | return (Element => A (I)'Access); | |
2169 | end; | |
a6dd3a54 ES |
2170 | end Reference; |
2171 | ||
1e194575 AC |
2172 | --------------------- |
2173 | -- Replace_Element -- | |
2174 | --------------------- | |
2175 | ||
2176 | procedure Replace_Element | |
2177 | (Container : in out Vector; | |
2178 | Index : Index_Type; | |
2179 | New_Item : Element_Type) | |
2180 | is | |
2181 | begin | |
2182 | if Index > Container.Last then | |
2183 | raise Constraint_Error with "Index is out of range"; | |
2184 | end if; | |
2185 | ||
2186 | if Container.Lock > 0 then | |
2187 | raise Program_Error with | |
2188 | "attempt to tamper with elements (vector is locked)"; | |
2189 | end if; | |
2190 | ||
2191 | Container.Elements (To_Array_Index (Index)) := New_Item; | |
2192 | end Replace_Element; | |
2193 | ||
2194 | procedure Replace_Element | |
2195 | (Container : in out Vector; | |
2196 | Position : Cursor; | |
2197 | New_Item : Element_Type) | |
2198 | is | |
2199 | begin | |
2200 | if Position.Container = null then | |
2201 | raise Constraint_Error with "Position cursor has no element"; | |
2202 | end if; | |
2203 | ||
2204 | if Position.Container /= Container'Unrestricted_Access then | |
2205 | raise Program_Error with "Position cursor denotes wrong container"; | |
2206 | end if; | |
2207 | ||
2208 | if Position.Index > Container.Last then | |
2209 | raise Constraint_Error with "Position cursor is out of range"; | |
2210 | end if; | |
2211 | ||
2212 | if Container.Lock > 0 then | |
2213 | raise Program_Error with | |
2214 | "attempt to tamper with elements (vector is locked)"; | |
2215 | end if; | |
2216 | ||
2217 | Container.Elements (To_Array_Index (Position.Index)) := New_Item; | |
2218 | end Replace_Element; | |
2219 | ||
2220 | ---------------------- | |
2221 | -- Reserve_Capacity -- | |
2222 | ---------------------- | |
2223 | ||
2224 | procedure Reserve_Capacity | |
2225 | (Container : in out Vector; | |
2226 | Capacity : Count_Type) | |
2227 | is | |
2228 | begin | |
2229 | if Capacity > Container.Capacity then | |
2230 | raise Constraint_Error with "Capacity is out of range"; | |
2231 | end if; | |
2232 | end Reserve_Capacity; | |
2233 | ||
2234 | ---------------------- | |
2235 | -- Reverse_Elements -- | |
2236 | ---------------------- | |
2237 | ||
2238 | procedure Reverse_Elements (Container : in out Vector) is | |
a8551b5f AC |
2239 | E : Elements_Array renames Container.Elements; |
2240 | Idx : Count_Type; | |
2241 | Jdx : Count_Type; | |
1e194575 AC |
2242 | |
2243 | begin | |
2244 | if Container.Length <= 1 then | |
2245 | return; | |
2246 | end if; | |
2247 | ||
b727a82b AC |
2248 | -- The exception behavior for the vector container must match that for |
2249 | -- the list container, so we check for cursor tampering here (which will | |
2250 | -- catch more things) instead of for element tampering (which will catch | |
2251 | -- fewer things). It's true that the elements of this vector container | |
2252 | -- could be safely moved around while (say) an iteration is taking place | |
a8551b5f AC |
2253 | -- (iteration only increments the busy counter), and so technically |
2254 | -- all we would need here is a test for element tampering (indicated | |
2255 | -- by the lock counter), that's simply an artifact of our array-based | |
b727a82b AC |
2256 | -- implementation. Logically Reverse_Elements requires a check for |
2257 | -- cursor tampering. | |
2258 | ||
2259 | if Container.Busy > 0 then | |
1e194575 | 2260 | raise Program_Error with |
b727a82b | 2261 | "attempt to tamper with cursors (vector is busy)"; |
1e194575 AC |
2262 | end if; |
2263 | ||
2264 | Idx := 1; | |
2265 | Jdx := Container.Length; | |
2266 | while Idx < Jdx loop | |
2267 | declare | |
2268 | EI : constant Element_Type := E (Idx); | |
2269 | ||
2270 | begin | |
2271 | E (Idx) := E (Jdx); | |
2272 | E (Jdx) := EI; | |
2273 | end; | |
2274 | ||
2275 | Idx := Idx + 1; | |
2276 | Jdx := Jdx - 1; | |
2277 | end loop; | |
2278 | end Reverse_Elements; | |
2279 | ||
2280 | ------------------ | |
2281 | -- Reverse_Find -- | |
2282 | ------------------ | |
2283 | ||
2284 | function Reverse_Find | |
2285 | (Container : Vector; | |
2286 | Item : Element_Type; | |
2287 | Position : Cursor := No_Element) return Cursor | |
2288 | is | |
2289 | Last : Index_Type'Base; | |
2290 | ||
2291 | begin | |
2292 | if Position.Container /= null | |
2293 | and then Position.Container /= Container'Unrestricted_Access | |
2294 | then | |
2295 | raise Program_Error with "Position cursor denotes wrong container"; | |
2296 | end if; | |
2297 | ||
2298 | Last := | |
2299 | (if Position.Container = null or else Position.Index > Container.Last | |
2300 | then Container.Last | |
2301 | else Position.Index); | |
2302 | ||
2303 | for Indx in reverse Index_Type'First .. Last loop | |
2304 | if Container.Elements (To_Array_Index (Indx)) = Item then | |
2305 | return (Container'Unrestricted_Access, Indx); | |
2306 | end if; | |
2307 | end loop; | |
2308 | ||
2309 | return No_Element; | |
2310 | end Reverse_Find; | |
2311 | ||
2312 | ------------------------ | |
2313 | -- Reverse_Find_Index -- | |
2314 | ------------------------ | |
2315 | ||
2316 | function Reverse_Find_Index | |
2317 | (Container : Vector; | |
2318 | Item : Element_Type; | |
2319 | Index : Index_Type := Index_Type'Last) return Extended_Index | |
2320 | is | |
2321 | Last : constant Index_Type'Base := | |
2322 | Index_Type'Min (Container.Last, Index); | |
2323 | ||
2324 | begin | |
2325 | for Indx in reverse Index_Type'First .. Last loop | |
2326 | if Container.Elements (To_Array_Index (Indx)) = Item then | |
2327 | return Indx; | |
2328 | end if; | |
2329 | end loop; | |
2330 | ||
2331 | return No_Index; | |
2332 | end Reverse_Find_Index; | |
2333 | ||
2334 | --------------------- | |
2335 | -- Reverse_Iterate -- | |
2336 | --------------------- | |
2337 | ||
2338 | procedure Reverse_Iterate | |
2339 | (Container : Vector; | |
2340 | Process : not null access procedure (Position : Cursor)) | |
2341 | is | |
2342 | V : Vector renames Container'Unrestricted_Access.all; | |
2343 | B : Natural renames V.Busy; | |
2344 | ||
2345 | begin | |
2346 | B := B + 1; | |
2347 | ||
2348 | begin | |
2349 | for Indx in reverse Index_Type'First .. Container.Last loop | |
2350 | Process (Cursor'(Container'Unrestricted_Access, Indx)); | |
2351 | end loop; | |
2352 | exception | |
2353 | when others => | |
2354 | B := B - 1; | |
2355 | raise; | |
2356 | end; | |
2357 | ||
2358 | B := B - 1; | |
2359 | end Reverse_Iterate; | |
2360 | ||
2361 | ---------------- | |
2362 | -- Set_Length -- | |
2363 | ---------------- | |
2364 | ||
2365 | procedure Set_Length (Container : in out Vector; Length : Count_Type) is | |
2366 | Count : constant Count_Type'Base := Container.Length - Length; | |
2367 | ||
2368 | begin | |
2369 | -- Set_Length allows the user to set the length explicitly, instead of | |
2370 | -- implicitly as a side-effect of deletion or insertion. If the | |
2371 | -- requested length is less then the current length, this is equivalent | |
2372 | -- to deleting items from the back end of the vector. If the requested | |
2373 | -- length is greater than the current length, then this is equivalent to | |
2374 | -- inserting "space" (nonce items) at the end. | |
2375 | ||
2376 | if Count >= 0 then | |
2377 | Container.Delete_Last (Count); | |
2378 | ||
2379 | elsif Container.Last >= Index_Type'Last then | |
2380 | raise Constraint_Error with "vector is already at its maximum length"; | |
2381 | ||
2382 | else | |
2383 | Container.Insert_Space (Container.Last + 1, -Count); | |
2384 | end if; | |
2385 | end Set_Length; | |
2386 | ||
2387 | ---------- | |
2388 | -- Swap -- | |
2389 | ---------- | |
2390 | ||
2391 | procedure Swap (Container : in out Vector; I, J : Index_Type) is | |
2392 | E : Elements_Array renames Container.Elements; | |
2393 | ||
2394 | begin | |
2395 | if I > Container.Last then | |
2396 | raise Constraint_Error with "I index is out of range"; | |
2397 | end if; | |
2398 | ||
2399 | if J > Container.Last then | |
2400 | raise Constraint_Error with "J index is out of range"; | |
2401 | end if; | |
2402 | ||
2403 | if I = J then | |
2404 | return; | |
2405 | end if; | |
2406 | ||
2407 | if Container.Lock > 0 then | |
2408 | raise Program_Error with | |
2409 | "attempt to tamper with elements (vector is locked)"; | |
2410 | end if; | |
2411 | ||
2412 | declare | |
2413 | EI_Copy : constant Element_Type := E (To_Array_Index (I)); | |
2414 | begin | |
2415 | E (To_Array_Index (I)) := E (To_Array_Index (J)); | |
2416 | E (To_Array_Index (J)) := EI_Copy; | |
2417 | end; | |
2418 | end Swap; | |
2419 | ||
2420 | procedure Swap (Container : in out Vector; I, J : Cursor) is | |
2421 | begin | |
2422 | if I.Container = null then | |
2423 | raise Constraint_Error with "I cursor has no element"; | |
2424 | end if; | |
2425 | ||
2426 | if J.Container = null then | |
2427 | raise Constraint_Error with "J cursor has no element"; | |
2428 | end if; | |
2429 | ||
2430 | if I.Container /= Container'Unrestricted_Access then | |
2431 | raise Program_Error with "I cursor denotes wrong container"; | |
2432 | end if; | |
2433 | ||
2434 | if J.Container /= Container'Unrestricted_Access then | |
2435 | raise Program_Error with "J cursor denotes wrong container"; | |
2436 | end if; | |
2437 | ||
2438 | Swap (Container, I.Index, J.Index); | |
2439 | end Swap; | |
2440 | ||
2441 | -------------------- | |
2442 | -- To_Array_Index -- | |
2443 | -------------------- | |
2444 | ||
2445 | function To_Array_Index (Index : Index_Type'Base) return Count_Type'Base is | |
2446 | Offset : Count_Type'Base; | |
2447 | ||
2448 | begin | |
2449 | -- We know that | |
2450 | -- Index >= Index_Type'First | |
2451 | -- hence we also know that | |
2452 | -- Index - Index_Type'First >= 0 | |
d85fd922 | 2453 | |
1e194575 AC |
2454 | -- The issue is that even though 0 is guaranteed to be a value |
2455 | -- in the type Index_Type'Base, there's no guarantee that the | |
2456 | -- difference is a value in that type. To prevent overflow we | |
2457 | -- use the wider of Count_Type'Base and Index_Type'Base to | |
2458 | -- perform intermediate calculations. | |
2459 | ||
2460 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
2461 | Offset := Count_Type'Base (Index - Index_Type'First); | |
2462 | ||
2463 | else | |
2464 | Offset := Count_Type'Base (Index) - | |
2465 | Count_Type'Base (Index_Type'First); | |
2466 | end if; | |
2467 | ||
2468 | -- The array index subtype for all container element arrays | |
2469 | -- always starts with 1. | |
2470 | ||
2471 | return 1 + Offset; | |
2472 | end To_Array_Index; | |
2473 | ||
2474 | --------------- | |
2475 | -- To_Cursor -- | |
2476 | --------------- | |
2477 | ||
2478 | function To_Cursor | |
2479 | (Container : Vector; | |
2480 | Index : Extended_Index) return Cursor | |
2481 | is | |
2482 | begin | |
2483 | if Index not in Index_Type'First .. Container.Last then | |
2484 | return No_Element; | |
2485 | end if; | |
2486 | ||
2487 | return Cursor'(Container'Unrestricted_Access, Index); | |
2488 | end To_Cursor; | |
2489 | ||
2490 | -------------- | |
2491 | -- To_Index -- | |
2492 | -------------- | |
2493 | ||
2494 | function To_Index (Position : Cursor) return Extended_Index is | |
2495 | begin | |
2496 | if Position.Container = null then | |
2497 | return No_Index; | |
2498 | end if; | |
2499 | ||
2500 | if Position.Index <= Position.Container.Last then | |
2501 | return Position.Index; | |
2502 | end if; | |
2503 | ||
2504 | return No_Index; | |
2505 | end To_Index; | |
2506 | ||
2507 | --------------- | |
2508 | -- To_Vector -- | |
2509 | --------------- | |
2510 | ||
2511 | function To_Vector (Length : Count_Type) return Vector is | |
2512 | Index : Count_Type'Base; | |
2513 | Last : Index_Type'Base; | |
2514 | ||
2515 | begin | |
2516 | if Length = 0 then | |
2517 | return Empty_Vector; | |
2518 | end if; | |
2519 | ||
2520 | -- We create a vector object with a capacity that matches the specified | |
2521 | -- Length, but we do not allow the vector capacity (the length of the | |
2522 | -- internal array) to exceed the number of values in Index_Type'Range | |
2523 | -- (otherwise, there would be no way to refer to those components via an | |
2524 | -- index). We must therefore check whether the specified Length would | |
2525 | -- create a Last index value greater than Index_Type'Last. | |
2526 | ||
2527 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
2528 | -- We perform a two-part test. First we determine whether the | |
2529 | -- computed Last value lies in the base range of the type, and then | |
2530 | -- determine whether it lies in the range of the index (sub)type. | |
2531 | ||
2532 | -- Last must satisfy this relation: | |
2533 | -- First + Length - 1 <= Last | |
2534 | -- We regroup terms: | |
2535 | -- First - 1 <= Last - Length | |
2536 | -- Which can rewrite as: | |
2537 | -- No_Index <= Last - Length | |
2538 | ||
2539 | if Index_Type'Base'Last - Index_Type'Base (Length) < No_Index then | |
2540 | raise Constraint_Error with "Length is out of range"; | |
2541 | end if; | |
2542 | ||
2543 | -- We now know that the computed value of Last is within the base | |
2544 | -- range of the type, so it is safe to compute its value: | |
2545 | ||
2546 | Last := No_Index + Index_Type'Base (Length); | |
2547 | ||
2548 | -- Finally we test whether the value is within the range of the | |
2549 | -- generic actual index subtype: | |
2550 | ||
2551 | if Last > Index_Type'Last then | |
2552 | raise Constraint_Error with "Length is out of range"; | |
2553 | end if; | |
2554 | ||
2555 | elsif Index_Type'First <= 0 then | |
d85fd922 | 2556 | |
1e194575 AC |
2557 | -- Here we can compute Last directly, in the normal way. We know that |
2558 | -- No_Index is less than 0, so there is no danger of overflow when | |
2559 | -- adding the (positive) value of Length. | |
2560 | ||
2561 | Index := Count_Type'Base (No_Index) + Length; -- Last | |
2562 | ||
2563 | if Index > Count_Type'Base (Index_Type'Last) then | |
2564 | raise Constraint_Error with "Length is out of range"; | |
2565 | end if; | |
2566 | ||
2567 | -- We know that the computed value (having type Count_Type) of Last | |
2568 | -- is within the range of the generic actual index subtype, so it is | |
2569 | -- safe to convert to Index_Type: | |
2570 | ||
2571 | Last := Index_Type'Base (Index); | |
2572 | ||
2573 | else | |
2574 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we | |
2575 | -- must test the length indirectly (by working backwards from the | |
2576 | -- largest possible value of Last), in order to prevent overflow. | |
2577 | ||
2578 | Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index | |
2579 | ||
2580 | if Index < Count_Type'Base (No_Index) then | |
2581 | raise Constraint_Error with "Length is out of range"; | |
2582 | end if; | |
2583 | ||
2584 | -- We have determined that the value of Length would not create a | |
2585 | -- Last index value outside of the range of Index_Type, so we can now | |
2586 | -- safely compute its value. | |
2587 | ||
2588 | Last := Index_Type'Base (Count_Type'Base (No_Index) + Length); | |
2589 | end if; | |
2590 | ||
2591 | return V : Vector (Capacity => Length) do | |
2592 | V.Last := Last; | |
2593 | end return; | |
2594 | end To_Vector; | |
2595 | ||
2596 | function To_Vector | |
2597 | (New_Item : Element_Type; | |
2598 | Length : Count_Type) return Vector | |
2599 | is | |
2600 | Index : Count_Type'Base; | |
2601 | Last : Index_Type'Base; | |
2602 | ||
2603 | begin | |
2604 | if Length = 0 then | |
2605 | return Empty_Vector; | |
2606 | end if; | |
2607 | ||
2608 | -- We create a vector object with a capacity that matches the specified | |
2609 | -- Length, but we do not allow the vector capacity (the length of the | |
2610 | -- internal array) to exceed the number of values in Index_Type'Range | |
2611 | -- (otherwise, there would be no way to refer to those components via an | |
2612 | -- index). We must therefore check whether the specified Length would | |
2613 | -- create a Last index value greater than Index_Type'Last. | |
2614 | ||
2615 | if Index_Type'Base'Last >= Count_Type'Pos (Count_Type'Last) then | |
d85fd922 | 2616 | |
1e194575 AC |
2617 | -- We perform a two-part test. First we determine whether the |
2618 | -- computed Last value lies in the base range of the type, and then | |
2619 | -- determine whether it lies in the range of the index (sub)type. | |
2620 | ||
2621 | -- Last must satisfy this relation: | |
2622 | -- First + Length - 1 <= Last | |
2623 | -- We regroup terms: | |
2624 | -- First - 1 <= Last - Length | |
2625 | -- Which can rewrite as: | |
2626 | -- No_Index <= Last - Length | |
2627 | ||
2628 | if Index_Type'Base'Last - Index_Type'Base (Length) < No_Index then | |
2629 | raise Constraint_Error with "Length is out of range"; | |
2630 | end if; | |
2631 | ||
2632 | -- We now know that the computed value of Last is within the base | |
2633 | -- range of the type, so it is safe to compute its value: | |
2634 | ||
2635 | Last := No_Index + Index_Type'Base (Length); | |
2636 | ||
2637 | -- Finally we test whether the value is within the range of the | |
2638 | -- generic actual index subtype: | |
2639 | ||
2640 | if Last > Index_Type'Last then | |
2641 | raise Constraint_Error with "Length is out of range"; | |
2642 | end if; | |
2643 | ||
2644 | elsif Index_Type'First <= 0 then | |
d85fd922 | 2645 | |
1e194575 AC |
2646 | -- Here we can compute Last directly, in the normal way. We know that |
2647 | -- No_Index is less than 0, so there is no danger of overflow when | |
2648 | -- adding the (positive) value of Length. | |
2649 | ||
2650 | Index := Count_Type'Base (No_Index) + Length; -- same value as V.Last | |
2651 | ||
2652 | if Index > Count_Type'Base (Index_Type'Last) then | |
2653 | raise Constraint_Error with "Length is out of range"; | |
2654 | end if; | |
2655 | ||
2656 | -- We know that the computed value (having type Count_Type) of Last | |
2657 | -- is within the range of the generic actual index subtype, so it is | |
2658 | -- safe to convert to Index_Type: | |
2659 | ||
2660 | Last := Index_Type'Base (Index); | |
2661 | ||
2662 | else | |
2663 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we | |
2664 | -- must test the length indirectly (by working backwards from the | |
2665 | -- largest possible value of Last), in order to prevent overflow. | |
2666 | ||
2667 | Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index | |
2668 | ||
2669 | if Index < Count_Type'Base (No_Index) then | |
2670 | raise Constraint_Error with "Length is out of range"; | |
2671 | end if; | |
2672 | ||
2673 | -- We have determined that the value of Length would not create a | |
2674 | -- Last index value outside of the range of Index_Type, so we can now | |
2675 | -- safely compute its value. | |
2676 | ||
2677 | Last := Index_Type'Base (Count_Type'Base (No_Index) + Length); | |
2678 | end if; | |
2679 | ||
2680 | return V : Vector (Capacity => Length) do | |
2681 | V.Elements := (others => New_Item); | |
2682 | V.Last := Last; | |
2683 | end return; | |
2684 | end To_Vector; | |
2685 | ||
2686 | -------------------- | |
2687 | -- Update_Element -- | |
2688 | -------------------- | |
2689 | ||
2690 | procedure Update_Element | |
2691 | (Container : in out Vector; | |
2692 | Index : Index_Type; | |
2693 | Process : not null access procedure (Element : in out Element_Type)) | |
2694 | is | |
2695 | B : Natural renames Container.Busy; | |
2696 | L : Natural renames Container.Lock; | |
2697 | ||
2698 | begin | |
2699 | if Index > Container.Last then | |
2700 | raise Constraint_Error with "Index is out of range"; | |
2701 | end if; | |
2702 | ||
2703 | B := B + 1; | |
2704 | L := L + 1; | |
2705 | ||
2706 | begin | |
2707 | Process (Container.Elements (To_Array_Index (Index))); | |
2708 | exception | |
2709 | when others => | |
2710 | L := L - 1; | |
2711 | B := B - 1; | |
2712 | raise; | |
2713 | end; | |
2714 | ||
2715 | L := L - 1; | |
2716 | B := B - 1; | |
2717 | end Update_Element; | |
2718 | ||
2719 | procedure Update_Element | |
2720 | (Container : in out Vector; | |
2721 | Position : Cursor; | |
2722 | Process : not null access procedure (Element : in out Element_Type)) | |
2723 | is | |
2724 | begin | |
2725 | if Position.Container = null then | |
2726 | raise Constraint_Error with "Position cursor has no element"; | |
2727 | end if; | |
2728 | ||
2729 | if Position.Container /= Container'Unrestricted_Access then | |
2730 | raise Program_Error with "Position cursor denotes wrong container"; | |
2731 | end if; | |
2732 | ||
2733 | Update_Element (Container, Position.Index, Process); | |
2734 | end Update_Element; | |
2735 | ||
2736 | ----------- | |
2737 | -- Write -- | |
2738 | ----------- | |
2739 | ||
2740 | procedure Write | |
2741 | (Stream : not null access Root_Stream_Type'Class; | |
2742 | Container : Vector) | |
2743 | is | |
2744 | N : Count_Type; | |
2745 | ||
2746 | begin | |
2747 | N := Container.Length; | |
2748 | Count_Type'Base'Write (Stream, N); | |
2749 | ||
2750 | for J in 1 .. N loop | |
2751 | Element_Type'Write (Stream, Container.Elements (J)); | |
2752 | end loop; | |
2753 | end Write; | |
2754 | ||
2755 | procedure Write | |
2756 | (Stream : not null access Root_Stream_Type'Class; | |
2757 | Position : Cursor) | |
2758 | is | |
2759 | begin | |
2760 | raise Program_Error with "attempt to stream vector cursor"; | |
2761 | end Write; | |
2762 | ||
a6dd3a54 ES |
2763 | procedure Write |
2764 | (Stream : not null access Root_Stream_Type'Class; | |
2765 | Item : Reference_Type) | |
2766 | is | |
2767 | begin | |
2768 | raise Program_Error with "attempt to stream reference"; | |
2769 | end Write; | |
2770 | ||
2771 | procedure Write | |
2772 | (Stream : not null access Root_Stream_Type'Class; | |
2773 | Item : Constant_Reference_Type) | |
2774 | is | |
2775 | begin | |
2776 | raise Program_Error with "attempt to stream reference"; | |
2777 | end Write; | |
2778 | ||
1e194575 | 2779 | end Ada.Containers.Bounded_Vectors; |