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4c2d6a70 AC |
1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT LIBRARY COMPONENTS -- | |
4 | -- -- | |
8704d4b3 | 5 | -- A D A . C O N T A I N E R S . I N D E F I N I T E _ V E C T O R S -- |
4c2d6a70 AC |
6 | -- -- |
7 | -- B o d y -- | |
8 | -- -- | |
4b490c1e | 9 | -- Copyright (C) 2004-2020, Free Software Foundation, Inc. -- |
4c2d6a70 | 10 | -- -- |
4c2d6a70 AC |
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- -- | |
748086b7 | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
4c2d6a70 AC |
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 -- | |
748086b7 JJ |
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/>. -- | |
4c2d6a70 | 26 | -- -- |
3c25856a | 27 | -- This unit was originally developed by Matthew J Heaney. -- |
4c2d6a70 AC |
28 | ------------------------------------------------------------------------------ |
29 | ||
30 | with Ada.Containers.Generic_Array_Sort; | |
31 | with Ada.Unchecked_Deallocation; | |
35fae080 | 32 | |
ef992452 | 33 | with System; use type System.Address; |
4c2d6a70 AC |
34 | |
35 | package body Ada.Containers.Indefinite_Vectors is | |
36 | ||
e9f97e79 AC |
37 | pragma Warnings (Off, "variable ""Busy*"" is not referenced"); |
38 | pragma Warnings (Off, "variable ""Lock*"" is not referenced"); | |
14f73211 | 39 | -- See comment in Ada.Containers.Helpers |
e9f97e79 | 40 | |
4c2d6a70 | 41 | procedure Free is |
8704d4b3 | 42 | new Ada.Unchecked_Deallocation (Elements_Type, Elements_Access); |
4c2d6a70 AC |
43 | |
44 | procedure Free is | |
8704d4b3 | 45 | new Ada.Unchecked_Deallocation (Element_Type, Element_Access); |
4c2d6a70 | 46 | |
e9f97e79 AC |
47 | procedure Append_Slow_Path |
48 | (Container : in out Vector; | |
49 | New_Item : Element_Type; | |
50 | Count : Count_Type); | |
51 | -- This is the slow path for Append. This is split out to minimize the size | |
52 | -- of Append, because we have Inline (Append). | |
53 | ||
8704d4b3 MH |
54 | --------- |
55 | -- "&" -- | |
56 | --------- | |
4c2d6a70 | 57 | |
e9f97e79 AC |
58 | -- We decide that the capacity of the result of "&" is the minimum needed |
59 | -- -- the sum of the lengths of the vector parameters. We could decide to | |
60 | -- make it larger, but we have no basis for knowing how much larger, so we | |
61 | -- just allocate the minimum amount of storage. | |
4c2d6a70 | 62 | |
e9f97e79 | 63 | function "&" (Left, Right : Vector) return Vector is |
4c2d6a70 | 64 | begin |
e9f97e79 AC |
65 | return Result : Vector do |
66 | Reserve_Capacity (Result, Length (Left) + Length (Right)); | |
67 | Append (Result, Left); | |
68 | Append (Result, Right); | |
69 | end return; | |
8704d4b3 | 70 | end "&"; |
4c2d6a70 | 71 | |
e9f97e79 | 72 | function "&" (Left : Vector; Right : Element_Type) return Vector is |
8704d4b3 | 73 | begin |
e9f97e79 AC |
74 | return Result : Vector do |
75 | Reserve_Capacity (Result, Length (Left) + 1); | |
76 | Append (Result, Left); | |
77 | Append (Result, Right); | |
78 | end return; | |
8704d4b3 | 79 | end "&"; |
4c2d6a70 | 80 | |
e9f97e79 | 81 | function "&" (Left : Element_Type; Right : Vector) return Vector is |
4c2d6a70 | 82 | begin |
e9f97e79 AC |
83 | return Result : Vector do |
84 | Reserve_Capacity (Result, 1 + Length (Right)); | |
85 | Append (Result, Left); | |
86 | Append (Result, Right); | |
87 | end return; | |
8704d4b3 MH |
88 | end "&"; |
89 | ||
90 | function "&" (Left, Right : Element_Type) return Vector is | |
d43d5ef7 | 91 | begin |
e9f97e79 AC |
92 | return Result : Vector do |
93 | Reserve_Capacity (Result, 1 + 1); | |
94 | Append (Result, Left); | |
95 | Append (Result, Right); | |
96 | end return; | |
8704d4b3 MH |
97 | end "&"; |
98 | ||
99 | --------- | |
100 | -- "=" -- | |
101 | --------- | |
102 | ||
fa969310 | 103 | overriding function "=" (Left, Right : Vector) return Boolean is |
8704d4b3 | 104 | begin |
4c2d6a70 AC |
105 | if Left.Last /= Right.Last then |
106 | return False; | |
107 | end if; | |
108 | ||
a015ef67 AC |
109 | if Left.Length = 0 then |
110 | return True; | |
111 | end if; | |
4c2d6a70 | 112 | |
a015ef67 AC |
113 | declare |
114 | -- Per AI05-0022, the container implementation is required to detect | |
115 | -- element tampering by a generic actual subprogram. | |
116 | ||
117 | Lock_Left : With_Lock (Left.TC'Unrestricted_Access); | |
118 | Lock_Right : With_Lock (Right.TC'Unrestricted_Access); | |
119 | begin | |
120 | for J in Index_Type range Index_Type'First .. Left.Last loop | |
121 | if Left.Elements.EA (J) = null then | |
122 | if Right.Elements.EA (J) /= null then | |
123 | return False; | |
124 | end if; | |
4c2d6a70 | 125 | |
a015ef67 AC |
126 | elsif Right.Elements.EA (J) = null then |
127 | return False; | |
128 | ||
129 | elsif Left.Elements.EA (J).all /= Right.Elements.EA (J).all then | |
130 | return False; | |
131 | end if; | |
132 | end loop; | |
133 | end; | |
4c2d6a70 | 134 | |
e9f97e79 | 135 | return True; |
4c2d6a70 AC |
136 | end "="; |
137 | ||
8704d4b3 MH |
138 | ------------ |
139 | -- Adjust -- | |
140 | ------------ | |
4c2d6a70 | 141 | |
8704d4b3 | 142 | procedure Adjust (Container : in out Vector) is |
4c2d6a70 | 143 | begin |
a015ef67 AC |
144 | -- If the counts are nonzero, execution is technically erroneous, but |
145 | -- it seems friendly to allow things like concurrent "=" on shared | |
146 | -- constants. | |
147 | ||
148 | Zero_Counts (Container.TC); | |
149 | ||
d43d5ef7 | 150 | if Container.Last = No_Index then |
8704d4b3 | 151 | Container.Elements := null; |
4c2d6a70 AC |
152 | return; |
153 | end if; | |
154 | ||
155 | declare | |
8704d4b3 | 156 | L : constant Index_Type := Container.Last; |
f97ccb3a BD |
157 | E : Elements_Array renames |
158 | Container.Elements.EA (Index_Type'First .. L); | |
d43d5ef7 | 159 | |
4c2d6a70 | 160 | begin |
8704d4b3 MH |
161 | Container.Elements := null; |
162 | Container.Last := No_Index; | |
4c2d6a70 | 163 | |
f97ccb3a | 164 | Container.Elements := new Elements_Type (L); |
4c2d6a70 | 165 | |
2602b64e AC |
166 | for J in E'Range loop |
167 | if E (J) /= null then | |
168 | Container.Elements.EA (J) := new Element_Type'(E (J).all); | |
4c2d6a70 AC |
169 | end if; |
170 | ||
2602b64e | 171 | Container.Last := J; |
4c2d6a70 | 172 | end loop; |
4c2d6a70 | 173 | end; |
8704d4b3 | 174 | end Adjust; |
4c2d6a70 | 175 | |
8704d4b3 MH |
176 | ------------ |
177 | -- Append -- | |
178 | ------------ | |
4c2d6a70 | 179 | |
8704d4b3 | 180 | procedure Append (Container : in out Vector; New_Item : Vector) is |
4c2d6a70 | 181 | begin |
8704d4b3 MH |
182 | if Is_Empty (New_Item) then |
183 | return; | |
e9f97e79 | 184 | elsif Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 | 185 | raise Constraint_Error with "vector is already at its maximum length"; |
2602b64e AC |
186 | else |
187 | Insert (Container, Container.Last + 1, New_Item); | |
d43d5ef7 | 188 | end if; |
8704d4b3 | 189 | end Append; |
4c2d6a70 | 190 | |
8704d4b3 MH |
191 | procedure Append |
192 | (Container : in out Vector; | |
193 | New_Item : Element_Type; | |
194 | Count : Count_Type := 1) | |
195 | is | |
e9f97e79 AC |
196 | begin |
197 | -- In the general case, we pass the buck to Insert, but for efficiency, | |
198 | -- we check for the usual case where Count = 1 and the vector has enough | |
199 | -- room for at least one more element. | |
200 | ||
201 | if Count = 1 | |
202 | and then Container.Elements /= null | |
203 | and then Container.Last /= Container.Elements.Last | |
204 | then | |
205 | TC_Check (Container.TC); | |
206 | ||
207 | -- Increment Container.Last after assigning the New_Item, so we | |
208 | -- leave the Container unmodified in case Finalize/Adjust raises | |
209 | -- an exception. | |
210 | ||
211 | declare | |
212 | New_Last : constant Index_Type := Container.Last + 1; | |
213 | ||
214 | -- The element allocator may need an accessibility check in the | |
215 | -- case actual type is class-wide or has access discriminants | |
216 | -- (see RM 4.8(10.1) and AI12-0035). | |
217 | ||
218 | pragma Unsuppress (Accessibility_Check); | |
219 | begin | |
220 | Container.Elements.EA (New_Last) := new Element_Type'(New_Item); | |
221 | Container.Last := New_Last; | |
222 | end; | |
223 | ||
224 | else | |
225 | Append_Slow_Path (Container, New_Item, Count); | |
226 | end if; | |
227 | end Append; | |
228 | ||
229 | ---------------------- | |
230 | -- Append_Slow_Path -- | |
231 | ---------------------- | |
232 | ||
233 | procedure Append_Slow_Path | |
234 | (Container : in out Vector; | |
235 | New_Item : Element_Type; | |
236 | Count : Count_Type) | |
237 | is | |
4c2d6a70 AC |
238 | begin |
239 | if Count = 0 then | |
240 | return; | |
e9f97e79 | 241 | elsif Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 | 242 | raise Constraint_Error with "vector is already at its maximum length"; |
2602b64e AC |
243 | else |
244 | Insert (Container, Container.Last + 1, New_Item, Count); | |
d43d5ef7 | 245 | end if; |
e9f97e79 | 246 | end Append_Slow_Path; |
4c2d6a70 | 247 | |
a31945d7 AC |
248 | ------------ |
249 | -- Assign -- | |
250 | ------------ | |
251 | ||
252 | procedure Assign (Target : in out Vector; Source : Vector) is | |
253 | begin | |
254 | if Target'Address = Source'Address then | |
255 | return; | |
2602b64e AC |
256 | else |
257 | Target.Clear; | |
258 | Target.Append (Source); | |
a31945d7 | 259 | end if; |
a31945d7 AC |
260 | end Assign; |
261 | ||
8704d4b3 MH |
262 | -------------- |
263 | -- Capacity -- | |
264 | -------------- | |
4c2d6a70 | 265 | |
8704d4b3 | 266 | function Capacity (Container : Vector) return Count_Type is |
4c2d6a70 | 267 | begin |
8704d4b3 MH |
268 | if Container.Elements = null then |
269 | return 0; | |
2602b64e AC |
270 | else |
271 | return Container.Elements.EA'Length; | |
8704d4b3 | 272 | end if; |
8704d4b3 MH |
273 | end Capacity; |
274 | ||
275 | ----------- | |
276 | -- Clear -- | |
277 | ----------- | |
278 | ||
279 | procedure Clear (Container : in out Vector) is | |
280 | begin | |
e9f97e79 | 281 | TC_Check (Container.TC); |
4c2d6a70 | 282 | |
e9f97e79 AC |
283 | while Container.Last >= Index_Type'First loop |
284 | declare | |
285 | X : Element_Access := Container.Elements.EA (Container.Last); | |
286 | begin | |
287 | Container.Elements.EA (Container.Last) := null; | |
288 | Container.Last := Container.Last - 1; | |
289 | Free (X); | |
290 | end; | |
291 | end loop; | |
8704d4b3 | 292 | end Clear; |
4c2d6a70 | 293 | |
0b5b2bbc AC |
294 | ------------------------ |
295 | -- Constant_Reference -- | |
296 | ------------------------ | |
297 | ||
298 | function Constant_Reference | |
c9423ca3 | 299 | (Container : aliased Vector; |
0b5b2bbc AC |
300 | Position : Cursor) return Constant_Reference_Type |
301 | is | |
c9423ca3 | 302 | begin |
e9f97e79 AC |
303 | if Checks then |
304 | if Position.Container = null then | |
305 | raise Constraint_Error with "Position cursor has no element"; | |
306 | end if; | |
0b5b2bbc | 307 | |
e9f97e79 AC |
308 | if Position.Container /= Container'Unrestricted_Access then |
309 | raise Program_Error with "Position cursor denotes wrong container"; | |
310 | end if; | |
c9423ca3 | 311 | |
e9f97e79 AC |
312 | if Position.Index > Position.Container.Last then |
313 | raise Constraint_Error with "Position cursor is out of range"; | |
314 | end if; | |
c9423ca3 AC |
315 | end if; |
316 | ||
14f73211 BD |
317 | declare |
318 | TC : constant Tamper_Counts_Access := | |
319 | Container.TC'Unrestricted_Access; | |
320 | begin | |
321 | -- The following will raise Constraint_Error if Element is null | |
322 | ||
794b9b72 | 323 | return R : constant Constant_Reference_Type := |
e9f97e79 | 324 | (Element => Container.Elements.EA (Position.Index), |
14f73211 BD |
325 | Control => (Controlled with TC)) |
326 | do | |
2f26abcc | 327 | Busy (TC.all); |
14f73211 BD |
328 | end return; |
329 | end; | |
0b5b2bbc AC |
330 | end Constant_Reference; |
331 | ||
332 | function Constant_Reference | |
c9423ca3 AC |
333 | (Container : aliased Vector; |
334 | Index : Index_Type) return Constant_Reference_Type | |
0b5b2bbc AC |
335 | is |
336 | begin | |
e9f97e79 | 337 | if Checks and then Index > Container.Last then |
0b5b2bbc AC |
338 | raise Constraint_Error with "Index is out of range"; |
339 | end if; | |
340 | ||
14f73211 BD |
341 | declare |
342 | TC : constant Tamper_Counts_Access := | |
343 | Container.TC'Unrestricted_Access; | |
344 | begin | |
345 | -- The following will raise Constraint_Error if Element is null | |
346 | ||
794b9b72 | 347 | return R : constant Constant_Reference_Type := |
e9f97e79 | 348 | (Element => Container.Elements.EA (Index), |
14f73211 BD |
349 | Control => (Controlled with TC)) |
350 | do | |
2f26abcc | 351 | Busy (TC.all); |
14f73211 BD |
352 | end return; |
353 | end; | |
0b5b2bbc AC |
354 | end Constant_Reference; |
355 | ||
8704d4b3 MH |
356 | -------------- |
357 | -- Contains -- | |
358 | -------------- | |
4c2d6a70 | 359 | |
8704d4b3 MH |
360 | function Contains |
361 | (Container : Vector; | |
2368f04e MH |
362 | Item : Element_Type) return Boolean |
363 | is | |
8704d4b3 MH |
364 | begin |
365 | return Find_Index (Container, Item) /= No_Index; | |
366 | end Contains; | |
4c2d6a70 | 367 | |
a31945d7 AC |
368 | ---------- |
369 | -- Copy -- | |
370 | ---------- | |
371 | ||
372 | function Copy | |
373 | (Source : Vector; | |
374 | Capacity : Count_Type := 0) return Vector | |
375 | is | |
376 | C : Count_Type; | |
377 | ||
378 | begin | |
06f6c43f AC |
379 | if Capacity < Source.Length then |
380 | if Checks and then Capacity /= 0 then | |
381 | raise Capacity_Error | |
382 | with "Requested capacity is less than Source length"; | |
383 | end if; | |
a31945d7 | 384 | |
06f6c43f AC |
385 | C := Source.Length; |
386 | else | |
a31945d7 | 387 | C := Capacity; |
a31945d7 AC |
388 | end if; |
389 | ||
390 | return Target : Vector do | |
391 | Target.Reserve_Capacity (C); | |
392 | Target.Assign (Source); | |
393 | end return; | |
394 | end Copy; | |
395 | ||
8704d4b3 MH |
396 | ------------ |
397 | -- Delete -- | |
398 | ------------ | |
4c2d6a70 | 399 | |
8704d4b3 MH |
400 | procedure Delete |
401 | (Container : in out Vector; | |
402 | Index : Extended_Index; | |
403 | Count : Count_Type := 1) | |
404 | is | |
5bec9717 AC |
405 | Old_Last : constant Index_Type'Base := Container.Last; |
406 | New_Last : Index_Type'Base; | |
407 | Count2 : Count_Type'Base; -- count of items from Index to Old_Last | |
408 | J : Index_Type'Base; -- first index of items that slide down | |
409 | ||
8704d4b3 | 410 | begin |
5bec9717 AC |
411 | -- Delete removes items from the vector, the number of which is the |
412 | -- minimum of the specified Count and the items (if any) that exist from | |
413 | -- Index to Container.Last. There are no constraints on the specified | |
414 | -- value of Count (it can be larger than what's available at this | |
415 | -- position in the vector, for example), but there are constraints on | |
416 | -- the allowed values of the Index. | |
417 | ||
418 | -- As a precondition on the generic actual Index_Type, the base type | |
419 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
420 | -- that Container.Last assumes when the vector is empty. However, we do | |
421 | -- not allow that as the value for Index when specifying which items | |
422 | -- should be deleted, so we must manually check. (That the user is | |
423 | -- allowed to specify the value at all here is a consequence of the | |
424 | -- declaration of the Extended_Index subtype, which includes the values | |
425 | -- in the base range that immediately precede and immediately follow the | |
426 | -- values in the Index_Type.) | |
427 | ||
e9f97e79 | 428 | if Checks and then Index < Index_Type'First then |
dc6b9ba2 | 429 | raise Constraint_Error with "Index is out of range (too small)"; |
8704d4b3 | 430 | end if; |
4c2d6a70 | 431 | |
5bec9717 AC |
432 | -- We do allow a value greater than Container.Last to be specified as |
433 | -- the Index, but only if it's immediately greater. This allows the | |
434 | -- corner case of deleting no items from the back end of the vector to | |
435 | -- be treated as a no-op. (It is assumed that specifying an index value | |
436 | -- greater than Last + 1 indicates some deeper flaw in the caller's | |
437 | -- algorithm, so that case is treated as a proper error.) | |
438 | ||
439 | if Index > Old_Last then | |
e9f97e79 | 440 | if Checks and then Index > Old_Last + 1 then |
dc6b9ba2 | 441 | raise Constraint_Error with "Index is out of range (too large)"; |
2602b64e AC |
442 | else |
443 | return; | |
8704d4b3 | 444 | end if; |
8704d4b3 | 445 | end if; |
4c2d6a70 | 446 | |
5bec9717 AC |
447 | -- Here and elsewhere we treat deleting 0 items from the container as a |
448 | -- no-op, even when the container is busy, so we simply return. | |
449 | ||
8704d4b3 | 450 | if Count = 0 then |
4c2d6a70 | 451 | return; |
8704d4b3 | 452 | end if; |
4c2d6a70 | 453 | |
5bec9717 AC |
454 | -- The internal elements array isn't guaranteed to exist unless we have |
455 | -- elements, so we handle that case here in order to avoid having to | |
456 | -- check it later. (Note that an empty vector can never be busy, so | |
457 | -- there's no semantic harm in returning early.) | |
458 | ||
459 | if Container.Is_Empty then | |
460 | return; | |
461 | end if; | |
462 | ||
463 | -- The tampering bits exist to prevent an item from being deleted (or | |
464 | -- otherwise harmfully manipulated) while it is being visited. Query, | |
465 | -- Update, and Iterate increment the busy count on entry, and decrement | |
466 | -- the count on exit. Delete checks the count to determine whether it is | |
467 | -- being called while the associated callback procedure is executing. | |
468 | ||
e9f97e79 | 469 | TC_Check (Container.TC); |
4c2d6a70 | 470 | |
5bec9717 AC |
471 | -- We first calculate what's available for deletion starting at |
472 | -- Index. Here and elsewhere we use the wider of Index_Type'Base and | |
473 | -- Count_Type'Base as the type for intermediate values. (See function | |
474 | -- Length for more information.) | |
475 | ||
476 | if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then | |
477 | Count2 := Count_Type'Base (Old_Last) - Count_Type'Base (Index) + 1; | |
5bec9717 AC |
478 | else |
479 | Count2 := Count_Type'Base (Old_Last - Index + 1); | |
480 | end if; | |
4c2d6a70 | 481 | |
5bec9717 AC |
482 | -- If the number of elements requested (Count) for deletion is equal to |
483 | -- (or greater than) the number of elements available (Count2) for | |
484 | -- deletion beginning at Index, then everything from Index to | |
485 | -- Container.Last is deleted (this is equivalent to Delete_Last). | |
4c2d6a70 | 486 | |
5bec9717 AC |
487 | if Count >= Count2 then |
488 | -- Elements in an indefinite vector are allocated, so we must iterate | |
489 | -- over the loop and deallocate elements one-at-a-time. We work from | |
490 | -- back to front, deleting the last element during each pass, in | |
491 | -- order to gracefully handle deallocation failures. | |
492 | ||
493 | declare | |
494 | EA : Elements_Array renames Container.Elements.EA; | |
495 | ||
496 | begin | |
d43d5ef7 MH |
497 | while Container.Last >= Index loop |
498 | declare | |
499 | K : constant Index_Type := Container.Last; | |
5bec9717 | 500 | X : Element_Access := EA (K); |
4c2d6a70 | 501 | |
d43d5ef7 | 502 | begin |
5bec9717 AC |
503 | -- We first isolate the element we're deleting, removing it |
504 | -- from the vector before we attempt to deallocate it, in | |
505 | -- case the deallocation fails. | |
506 | ||
507 | EA (K) := null; | |
d43d5ef7 | 508 | Container.Last := K - 1; |
5bec9717 AC |
509 | |
510 | -- Container invariants have been restored, so it is now | |
511 | -- safe to attempt to deallocate the element. | |
512 | ||
d43d5ef7 MH |
513 | Free (X); |
514 | end; | |
515 | end loop; | |
5bec9717 | 516 | end; |
4c2d6a70 | 517 | |
5bec9717 AC |
518 | return; |
519 | end if; | |
520 | ||
521 | -- There are some elements that aren't being deleted (the requested | |
522 | -- count was less than the available count), so we must slide them down | |
523 | -- to Index. We first calculate the index values of the respective array | |
524 | -- slices, using the wider of Index_Type'Base and Count_Type'Base as the | |
525 | -- type for intermediate calculations. For the elements that slide down, | |
526 | -- index value New_Last is the last index value of their new home, and | |
527 | -- index value J is the first index of their old home. | |
4c2d6a70 | 528 | |
e9f97e79 | 529 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 AC |
530 | New_Last := Old_Last - Index_Type'Base (Count); |
531 | J := Index + Index_Type'Base (Count); | |
5bec9717 AC |
532 | else |
533 | New_Last := Index_Type'Base (Count_Type'Base (Old_Last) - Count); | |
534 | J := Index_Type'Base (Count_Type'Base (Index) + Count); | |
535 | end if; | |
536 | ||
537 | -- The internal elements array isn't guaranteed to exist unless we have | |
538 | -- elements, but we have that guarantee here because we know we have | |
539 | -- elements to slide. The array index values for each slice have | |
540 | -- already been determined, so what remains to be done is to first | |
541 | -- deallocate the elements that are being deleted, and then slide down | |
542 | -- to Index the elements that aren't being deleted. | |
543 | ||
544 | declare | |
545 | EA : Elements_Array renames Container.Elements.EA; | |
546 | ||
547 | begin | |
548 | -- Before we can slide down the elements that aren't being deleted, | |
549 | -- we need to deallocate the elements that are being deleted. | |
550 | ||
551 | for K in Index .. J - 1 loop | |
552 | declare | |
553 | X : Element_Access := EA (K); | |
8704d4b3 | 554 | |
8704d4b3 | 555 | begin |
5bec9717 AC |
556 | -- First we remove the element we're about to deallocate from |
557 | -- the vector, in case the deallocation fails, in order to | |
558 | -- preserve representation invariants. | |
8704d4b3 | 559 | |
5bec9717 AC |
560 | EA (K) := null; |
561 | ||
562 | -- The element has been removed from the vector, so it is now | |
563 | -- safe to attempt to deallocate it. | |
564 | ||
565 | Free (X); | |
d43d5ef7 | 566 | end; |
5bec9717 AC |
567 | end loop; |
568 | ||
569 | EA (Index .. New_Last) := EA (J .. Old_Last); | |
570 | Container.Last := New_Last; | |
8704d4b3 MH |
571 | end; |
572 | end Delete; | |
4c2d6a70 | 573 | |
8704d4b3 MH |
574 | procedure Delete |
575 | (Container : in out Vector; | |
576 | Position : in out Cursor; | |
577 | Count : Count_Type := 1) | |
578 | is | |
579 | begin | |
e9f97e79 AC |
580 | if Checks then |
581 | if Position.Container = null then | |
582 | raise Constraint_Error with "Position cursor has no element"; | |
dc6b9ba2 | 583 | |
e9f97e79 AC |
584 | elsif Position.Container /= Container'Unrestricted_Access then |
585 | raise Program_Error with "Position cursor denotes wrong container"; | |
4c2d6a70 | 586 | |
e9f97e79 AC |
587 | elsif Position.Index > Container.Last then |
588 | raise Program_Error with "Position index is out of range"; | |
589 | end if; | |
2602b64e | 590 | end if; |
e9f97e79 AC |
591 | |
592 | Delete (Container, Position.Index, Count); | |
593 | Position := No_Element; | |
8704d4b3 | 594 | end Delete; |
4c2d6a70 | 595 | |
8704d4b3 MH |
596 | ------------------ |
597 | -- Delete_First -- | |
598 | ------------------ | |
4c2d6a70 | 599 | |
8704d4b3 MH |
600 | procedure Delete_First |
601 | (Container : in out Vector; | |
602 | Count : Count_Type := 1) | |
603 | is | |
604 | begin | |
605 | if Count = 0 then | |
606 | return; | |
4c2d6a70 | 607 | |
2602b64e | 608 | elsif Count >= Length (Container) then |
8704d4b3 MH |
609 | Clear (Container); |
610 | return; | |
4c2d6a70 | 611 | |
2602b64e AC |
612 | else |
613 | Delete (Container, Index_Type'First, Count); | |
614 | end if; | |
8704d4b3 | 615 | end Delete_First; |
4c2d6a70 | 616 | |
8704d4b3 MH |
617 | ----------------- |
618 | -- Delete_Last -- | |
619 | ----------------- | |
4c2d6a70 | 620 | |
8704d4b3 MH |
621 | procedure Delete_Last |
622 | (Container : in out Vector; | |
623 | Count : Count_Type := 1) | |
624 | is | |
8704d4b3 | 625 | begin |
5bec9717 AC |
626 | -- It is not permitted to delete items while the container is busy (for |
627 | -- example, we're in the middle of a passive iteration). However, we | |
628 | -- always treat deleting 0 items as a no-op, even when we're busy, so we | |
629 | -- simply return without checking. | |
630 | ||
631 | if Count = 0 then | |
632 | return; | |
633 | end if; | |
634 | ||
635 | -- We cannot simply subsume the empty case into the loop below (the loop | |
636 | -- would iterate 0 times), because we rename the internal array object | |
637 | -- (which is allocated), but an empty vector isn't guaranteed to have | |
638 | -- actually allocated an array. (Note that an empty vector can never be | |
639 | -- busy, so there's no semantic harm in returning early here.) | |
640 | ||
641 | if Container.Is_Empty then | |
8704d4b3 MH |
642 | return; |
643 | end if; | |
4c2d6a70 | 644 | |
5bec9717 AC |
645 | -- The tampering bits exist to prevent an item from being deleted (or |
646 | -- otherwise harmfully manipulated) while it is being visited. Query, | |
647 | -- Update, and Iterate increment the busy count on entry, and decrement | |
648 | -- the count on exit. Delete_Last checks the count to determine whether | |
649 | -- it is being called while the associated callback procedure is | |
650 | -- executing. | |
651 | ||
e9f97e79 | 652 | TC_Check (Container.TC); |
4c2d6a70 | 653 | |
5bec9717 AC |
654 | -- Elements in an indefinite vector are allocated, so we must iterate |
655 | -- over the loop and deallocate elements one-at-a-time. We work from | |
656 | -- back to front, deleting the last element during each pass, in order | |
657 | -- to gracefully handle deallocation failures. | |
658 | ||
d43d5ef7 | 659 | declare |
f97ccb3a | 660 | E : Elements_Array renames Container.Elements.EA; |
4c2d6a70 | 661 | |
d43d5ef7 | 662 | begin |
5bec9717 | 663 | for Indx in 1 .. Count_Type'Min (Count, Container.Length) loop |
d43d5ef7 MH |
664 | declare |
665 | J : constant Index_Type := Container.Last; | |
666 | X : Element_Access := E (J); | |
667 | ||
668 | begin | |
5bec9717 AC |
669 | -- Note that we first isolate the element we're deleting, |
670 | -- removing it from the vector, before we actually deallocate | |
671 | -- it, in order to preserve representation invariants even if | |
672 | -- the deallocation fails. | |
673 | ||
d43d5ef7 MH |
674 | E (J) := null; |
675 | Container.Last := J - 1; | |
5bec9717 AC |
676 | |
677 | -- Container invariants have been restored, so it is now safe | |
678 | -- to deallocate the element. | |
679 | ||
d43d5ef7 MH |
680 | Free (X); |
681 | end; | |
682 | end loop; | |
683 | end; | |
8704d4b3 | 684 | end Delete_Last; |
4c2d6a70 | 685 | |
8704d4b3 MH |
686 | ------------- |
687 | -- Element -- | |
688 | ------------- | |
4c2d6a70 | 689 | |
8704d4b3 MH |
690 | function Element |
691 | (Container : Vector; | |
692 | Index : Index_Type) return Element_Type | |
693 | is | |
8704d4b3 | 694 | begin |
e9f97e79 | 695 | if Checks and then Index > Container.Last then |
dc6b9ba2 | 696 | raise Constraint_Error with "Index is out of range"; |
d43d5ef7 MH |
697 | end if; |
698 | ||
2368f04e | 699 | declare |
f97ccb3a | 700 | EA : constant Element_Access := Container.Elements.EA (Index); |
2368f04e | 701 | begin |
e9f97e79 | 702 | if Checks and then EA = null then |
dc6b9ba2 | 703 | raise Constraint_Error with "element is empty"; |
2602b64e AC |
704 | else |
705 | return EA.all; | |
2368f04e | 706 | end if; |
2368f04e | 707 | end; |
8704d4b3 | 708 | end Element; |
4c2d6a70 | 709 | |
8704d4b3 MH |
710 | function Element (Position : Cursor) return Element_Type is |
711 | begin | |
e9f97e79 AC |
712 | if Checks then |
713 | if Position.Container = null then | |
714 | raise Constraint_Error with "Position cursor has no element"; | |
715 | end if; | |
d43d5ef7 | 716 | |
e9f97e79 AC |
717 | if Position.Index > Position.Container.Last then |
718 | raise Constraint_Error with "Position cursor is out of range"; | |
719 | end if; | |
f97ccb3a BD |
720 | end if; |
721 | ||
722 | declare | |
723 | EA : constant Element_Access := | |
2602b64e | 724 | Position.Container.Elements.EA (Position.Index); |
f97ccb3a | 725 | begin |
e9f97e79 | 726 | if Checks and then EA = null then |
f97ccb3a | 727 | raise Constraint_Error with "element is empty"; |
2602b64e AC |
728 | else |
729 | return EA.all; | |
f97ccb3a | 730 | end if; |
f97ccb3a | 731 | end; |
8704d4b3 | 732 | end Element; |
4c2d6a70 | 733 | |
8704d4b3 MH |
734 | -------------- |
735 | -- Finalize -- | |
736 | -------------- | |
4c2d6a70 | 737 | |
8704d4b3 MH |
738 | procedure Finalize (Container : in out Vector) is |
739 | begin | |
dc6b9ba2 | 740 | Clear (Container); -- Checks busy-bit |
4c2d6a70 AC |
741 | |
742 | declare | |
743 | X : Elements_Access := Container.Elements; | |
744 | begin | |
8704d4b3 | 745 | Container.Elements := null; |
4c2d6a70 AC |
746 | Free (X); |
747 | end; | |
8704d4b3 | 748 | end Finalize; |
4c2d6a70 | 749 | |
ef992452 AC |
750 | procedure Finalize (Object : in out Iterator) is |
751 | begin | |
e9f97e79 | 752 | Unbusy (Object.Container.TC); |
794b9b72 AC |
753 | end Finalize; |
754 | ||
8704d4b3 MH |
755 | ---------- |
756 | -- Find -- | |
757 | ---------- | |
4c2d6a70 | 758 | |
8704d4b3 MH |
759 | function Find |
760 | (Container : Vector; | |
761 | Item : Element_Type; | |
2368f04e MH |
762 | Position : Cursor := No_Element) return Cursor |
763 | is | |
8704d4b3 | 764 | begin |
e9f97e79 | 765 | if Checks and then Position.Container /= null then |
dc6b9ba2 MH |
766 | if Position.Container /= Container'Unrestricted_Access then |
767 | raise Program_Error with "Position cursor denotes wrong container"; | |
768 | end if; | |
769 | ||
770 | if Position.Index > Container.Last then | |
771 | raise Program_Error with "Position index is out of range"; | |
772 | end if; | |
8704d4b3 | 773 | end if; |
4c2d6a70 | 774 | |
2602b64e AC |
775 | -- Per AI05-0022, the container implementation is required to detect |
776 | -- element tampering by a generic actual subprogram. | |
777 | ||
778 | declare | |
e9f97e79 | 779 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
2602b64e | 780 | begin |
2602b64e | 781 | for J in Position.Index .. Container.Last loop |
e9f97e79 AC |
782 | if Container.Elements.EA (J).all = Item then |
783 | return Cursor'(Container'Unrestricted_Access, J); | |
2602b64e AC |
784 | end if; |
785 | end loop; | |
786 | ||
e9f97e79 | 787 | return No_Element; |
2602b64e | 788 | end; |
8704d4b3 | 789 | end Find; |
4c2d6a70 | 790 | |
8704d4b3 MH |
791 | ---------------- |
792 | -- Find_Index -- | |
793 | ---------------- | |
4c2d6a70 | 794 | |
8704d4b3 MH |
795 | function Find_Index |
796 | (Container : Vector; | |
797 | Item : Element_Type; | |
2368f04e MH |
798 | Index : Index_Type := Index_Type'First) return Extended_Index |
799 | is | |
2602b64e AC |
800 | -- Per AI05-0022, the container implementation is required to detect |
801 | -- element tampering by a generic actual subprogram. | |
802 | ||
e9f97e79 AC |
803 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
804 | begin | |
8704d4b3 | 805 | for Indx in Index .. Container.Last loop |
e9f97e79 AC |
806 | if Container.Elements.EA (Indx).all = Item then |
807 | return Indx; | |
8704d4b3 MH |
808 | end if; |
809 | end loop; | |
810 | ||
e9f97e79 | 811 | return No_Index; |
8704d4b3 | 812 | end Find_Index; |
4c2d6a70 | 813 | |
8704d4b3 MH |
814 | ----------- |
815 | -- First -- | |
816 | ----------- | |
4c2d6a70 | 817 | |
8704d4b3 MH |
818 | function First (Container : Vector) return Cursor is |
819 | begin | |
820 | if Is_Empty (Container) then | |
821 | return No_Element; | |
822 | end if; | |
4c2d6a70 | 823 | |
ef992452 | 824 | return (Container'Unrestricted_Access, Index_Type'First); |
8704d4b3 | 825 | end First; |
4c2d6a70 | 826 | |
3e24afaa | 827 | function First (Object : Iterator) return Cursor is |
3e24afaa | 828 | begin |
e8bd500e AC |
829 | -- The value of the iterator object's Index component influences the |
830 | -- behavior of the First (and Last) selector function. | |
831 | ||
fe58fea7 AC |
832 | -- When the Index component is No_Index, this means the iterator |
833 | -- object was constructed without a start expression, in which case the | |
e8bd500e AC |
834 | -- (forward) iteration starts from the (logical) beginning of the entire |
835 | -- sequence of items (corresponding to Container.First, for a forward | |
836 | -- iterator). | |
837 | ||
fe58fea7 AC |
838 | -- Otherwise, this is iteration over a partial sequence of items. |
839 | -- When the Index component isn't No_Index, the iterator object was | |
840 | -- constructed with a start expression, that specifies the position | |
841 | -- from which the (forward) partial iteration begins. | |
e8bd500e AC |
842 | |
843 | if Object.Index = No_Index then | |
844 | return First (Object.Container.all); | |
845 | else | |
846 | return Cursor'(Object.Container, Object.Index); | |
847 | end if; | |
3e24afaa AC |
848 | end First; |
849 | ||
8704d4b3 MH |
850 | ------------------- |
851 | -- First_Element -- | |
852 | ------------------- | |
4c2d6a70 | 853 | |
8704d4b3 | 854 | function First_Element (Container : Vector) return Element_Type is |
4c2d6a70 | 855 | begin |
e9f97e79 | 856 | if Checks and then Container.Last = No_Index then |
f97ccb3a BD |
857 | raise Constraint_Error with "Container is empty"; |
858 | end if; | |
859 | ||
860 | declare | |
861 | EA : constant Element_Access := | |
2602b64e | 862 | Container.Elements.EA (Index_Type'First); |
f97ccb3a | 863 | begin |
e9f97e79 | 864 | if Checks and then EA = null then |
f97ccb3a | 865 | raise Constraint_Error with "first element is empty"; |
2602b64e AC |
866 | else |
867 | return EA.all; | |
f97ccb3a | 868 | end if; |
f97ccb3a | 869 | end; |
8704d4b3 | 870 | end First_Element; |
4c2d6a70 | 871 | |
8704d4b3 MH |
872 | ----------------- |
873 | -- First_Index -- | |
874 | ----------------- | |
4c2d6a70 | 875 | |
8704d4b3 MH |
876 | function First_Index (Container : Vector) return Index_Type is |
877 | pragma Unreferenced (Container); | |
878 | begin | |
879 | return Index_Type'First; | |
880 | end First_Index; | |
4c2d6a70 | 881 | |
8704d4b3 MH |
882 | --------------------- |
883 | -- Generic_Sorting -- | |
884 | --------------------- | |
4c2d6a70 | 885 | |
8704d4b3 | 886 | package body Generic_Sorting is |
4c2d6a70 | 887 | |
8704d4b3 MH |
888 | ----------------------- |
889 | -- Local Subprograms -- | |
890 | ----------------------- | |
4c2d6a70 | 891 | |
8704d4b3 MH |
892 | function Is_Less (L, R : Element_Access) return Boolean; |
893 | pragma Inline (Is_Less); | |
4c2d6a70 | 894 | |
8704d4b3 MH |
895 | ------------- |
896 | -- Is_Less -- | |
897 | ------------- | |
4c2d6a70 | 898 | |
8704d4b3 MH |
899 | function Is_Less (L, R : Element_Access) return Boolean is |
900 | begin | |
901 | if L = null then | |
902 | return R /= null; | |
903 | elsif R = null then | |
904 | return False; | |
905 | else | |
906 | return L.all < R.all; | |
907 | end if; | |
908 | end Is_Less; | |
4c2d6a70 | 909 | |
8704d4b3 MH |
910 | --------------- |
911 | -- Is_Sorted -- | |
912 | --------------- | |
4c2d6a70 | 913 | |
8704d4b3 MH |
914 | function Is_Sorted (Container : Vector) return Boolean is |
915 | begin | |
916 | if Container.Last <= Index_Type'First then | |
917 | return True; | |
918 | end if; | |
4c2d6a70 | 919 | |
2602b64e AC |
920 | -- Per AI05-0022, the container implementation is required to detect |
921 | -- element tampering by a generic actual subprogram. | |
922 | ||
4c2d6a70 | 923 | declare |
e9f97e79 | 924 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
f97ccb3a | 925 | E : Elements_Array renames Container.Elements.EA; |
4c2d6a70 | 926 | begin |
e9f97e79 AC |
927 | for J in Index_Type'First .. Container.Last - 1 loop |
928 | if Is_Less (E (J + 1), E (J)) then | |
929 | return False; | |
8704d4b3 MH |
930 | end if; |
931 | end loop; | |
4c2d6a70 | 932 | |
e9f97e79 | 933 | return True; |
2602b64e | 934 | end; |
8704d4b3 | 935 | end Is_Sorted; |
4c2d6a70 | 936 | |
8704d4b3 MH |
937 | ----------- |
938 | -- Merge -- | |
939 | ----------- | |
4c2d6a70 | 940 | |
8704d4b3 | 941 | procedure Merge (Target, Source : in out Vector) is |
f97ccb3a | 942 | I, J : Index_Type'Base; |
4c2d6a70 | 943 | |
8704d4b3 | 944 | begin |
4c9fe6c7 AC |
945 | -- The semantics of Merge changed slightly per AI05-0021. It was |
946 | -- originally the case that if Target and Source denoted the same | |
947 | -- container object, then the GNAT implementation of Merge did | |
948 | -- nothing. However, it was argued that RM05 did not precisely | |
949 | -- specify the semantics for this corner case. The decision of the | |
950 | -- ARG was that if Target and Source denote the same non-empty | |
951 | -- container object, then Program_Error is raised. | |
952 | ||
953 | if Source.Last < Index_Type'First then -- Source is empty | |
8704d4b3 MH |
954 | return; |
955 | end if; | |
4c2d6a70 | 956 | |
e9f97e79 | 957 | if Checks and then Target'Address = Source'Address then |
4c9fe6c7 AC |
958 | raise Program_Error with |
959 | "Target and Source denote same non-empty container"; | |
8704d4b3 | 960 | end if; |
4c2d6a70 | 961 | |
4c9fe6c7 AC |
962 | if Target.Last < Index_Type'First then -- Target is empty |
963 | Move (Target => Target, Source => Source); | |
8704d4b3 MH |
964 | return; |
965 | end if; | |
4c2d6a70 | 966 | |
e9f97e79 | 967 | TC_Check (Source.TC); |
4c2d6a70 | 968 | |
f97ccb3a | 969 | I := Target.Last; -- original value (before Set_Length) |
8704d4b3 | 970 | Target.Set_Length (Length (Target) + Length (Source)); |
4c2d6a70 | 971 | |
2602b64e AC |
972 | -- Per AI05-0022, the container implementation is required to detect |
973 | -- element tampering by a generic actual subprogram. | |
974 | ||
975 | declare | |
976 | TA : Elements_Array renames Target.Elements.EA; | |
977 | SA : Elements_Array renames Source.Elements.EA; | |
978 | ||
e9f97e79 AC |
979 | Lock_Target : With_Lock (Target.TC'Unchecked_Access); |
980 | Lock_Source : With_Lock (Source.TC'Unchecked_Access); | |
2602b64e | 981 | begin |
2602b64e AC |
982 | J := Target.Last; -- new value (after Set_Length) |
983 | while Source.Last >= Index_Type'First loop | |
984 | pragma Assert | |
985 | (Source.Last <= Index_Type'First | |
986 | or else not (Is_Less (SA (Source.Last), | |
987 | SA (Source.Last - 1)))); | |
988 | ||
989 | if I < Index_Type'First then | |
990 | declare | |
991 | Src : Elements_Array renames | |
992 | SA (Index_Type'First .. Source.Last); | |
993 | begin | |
994 | TA (Index_Type'First .. J) := Src; | |
995 | Src := (others => null); | |
996 | end; | |
997 | ||
998 | Source.Last := No_Index; | |
999 | exit; | |
1000 | end if; | |
1001 | ||
1002 | pragma Assert | |
1003 | (I <= Index_Type'First | |
1004 | or else not (Is_Less (TA (I), TA (I - 1)))); | |
7cdc672b | 1005 | |
8704d4b3 | 1006 | declare |
2602b64e AC |
1007 | Src : Element_Access renames SA (Source.Last); |
1008 | Tgt : Element_Access renames TA (I); | |
4c2d6a70 | 1009 | |
8704d4b3 | 1010 | begin |
2602b64e AC |
1011 | if Is_Less (Src, Tgt) then |
1012 | Target.Elements.EA (J) := Tgt; | |
1013 | Tgt := null; | |
1014 | I := I - 1; | |
1015 | ||
1016 | else | |
1017 | Target.Elements.EA (J) := Src; | |
1018 | Src := null; | |
1019 | Source.Last := Source.Last - 1; | |
1020 | end if; | |
8704d4b3 | 1021 | end; |
4c2d6a70 | 1022 | |
2602b64e AC |
1023 | J := J - 1; |
1024 | end loop; | |
2602b64e | 1025 | end; |
8704d4b3 | 1026 | end Merge; |
4c2d6a70 | 1027 | |
8704d4b3 MH |
1028 | ---------- |
1029 | -- Sort -- | |
1030 | ---------- | |
4c2d6a70 | 1031 | |
3c25856a | 1032 | procedure Sort (Container : in out Vector) is |
3c25856a AC |
1033 | procedure Sort is new Generic_Array_Sort |
1034 | (Index_Type => Index_Type, | |
1035 | Element_Type => Element_Access, | |
1036 | Array_Type => Elements_Array, | |
1037 | "<" => Is_Less); | |
4c2d6a70 | 1038 | |
794b9b72 AC |
1039 | -- Start of processing for Sort |
1040 | ||
4c2d6a70 | 1041 | begin |
8704d4b3 MH |
1042 | if Container.Last <= Index_Type'First then |
1043 | return; | |
1044 | end if; | |
4c2d6a70 | 1045 | |
b727a82b AC |
1046 | -- The exception behavior for the vector container must match that |
1047 | -- for the list container, so we check for cursor tampering here | |
1048 | -- (which will catch more things) instead of for element tampering | |
1049 | -- (which will catch fewer things). It's true that the elements of | |
1050 | -- this vector container could be safely moved around while (say) an | |
1051 | -- iteration is taking place (iteration only increments the busy | |
1052 | -- counter), and so technically all we would need here is a test for | |
1053 | -- element tampering (indicated by the lock counter), that's simply | |
1054 | -- an artifact of our array-based implementation. Logically Sort | |
1055 | -- requires a check for cursor tampering. | |
1056 | ||
e9f97e79 | 1057 | TC_Check (Container.TC); |
4c2d6a70 | 1058 | |
2602b64e AC |
1059 | -- Per AI05-0022, the container implementation is required to detect |
1060 | -- element tampering by a generic actual subprogram. | |
1061 | ||
1062 | declare | |
e9f97e79 | 1063 | Lock : With_Lock (Container.TC'Unchecked_Access); |
2602b64e | 1064 | begin |
2602b64e | 1065 | Sort (Container.Elements.EA (Index_Type'First .. Container.Last)); |
2602b64e | 1066 | end; |
8704d4b3 | 1067 | end Sort; |
4c2d6a70 | 1068 | |
8704d4b3 | 1069 | end Generic_Sorting; |
4c2d6a70 | 1070 | |
e9f97e79 AC |
1071 | ------------------------ |
1072 | -- Get_Element_Access -- | |
1073 | ------------------------ | |
1074 | ||
1075 | function Get_Element_Access | |
72d5c70b AC |
1076 | (Position : Cursor) return not null Element_Access |
1077 | is | |
1078 | Ptr : constant Element_Access := | |
1079 | Position.Container.Elements.EA (Position.Index); | |
1080 | ||
e9f97e79 | 1081 | begin |
72d5c70b AC |
1082 | -- An indefinite vector may contain spaces that hold no elements. |
1083 | -- Any iteration over an indefinite vector with spaces will raise | |
1084 | -- Constraint_Error. | |
1085 | ||
1086 | if Ptr = null then | |
1087 | raise Constraint_Error; | |
1088 | ||
1089 | else | |
1090 | return Ptr; | |
1091 | end if; | |
e9f97e79 AC |
1092 | end Get_Element_Access; |
1093 | ||
8704d4b3 MH |
1094 | ----------------- |
1095 | -- Has_Element -- | |
1096 | ----------------- | |
4c2d6a70 | 1097 | |
8704d4b3 | 1098 | function Has_Element (Position : Cursor) return Boolean is |
4c2d6a70 | 1099 | begin |
8704d4b3 MH |
1100 | if Position.Container = null then |
1101 | return False; | |
2602b64e AC |
1102 | else |
1103 | return Position.Index <= Position.Container.Last; | |
4c2d6a70 | 1104 | end if; |
8704d4b3 | 1105 | end Has_Element; |
4c2d6a70 | 1106 | |
8704d4b3 MH |
1107 | ------------ |
1108 | -- Insert -- | |
1109 | ------------ | |
4c2d6a70 | 1110 | |
8704d4b3 MH |
1111 | procedure Insert |
1112 | (Container : in out Vector; | |
1113 | Before : Extended_Index; | |
1114 | New_Item : Element_Type; | |
1115 | Count : Count_Type := 1) | |
1116 | is | |
5bec9717 | 1117 | Old_Length : constant Count_Type := Container.Length; |
4c2d6a70 | 1118 | |
5bec9717 AC |
1119 | Max_Length : Count_Type'Base; -- determined from range of Index_Type |
1120 | New_Length : Count_Type'Base; -- sum of current length and Count | |
1121 | New_Last : Index_Type'Base; -- last index of vector after insertion | |
4c2d6a70 | 1122 | |
5bec9717 AC |
1123 | Index : Index_Type'Base; -- scratch for intermediate values |
1124 | J : Count_Type'Base; -- scratch | |
1125 | ||
1126 | New_Capacity : Count_Type'Base; -- length of new, expanded array | |
1127 | Dst_Last : Index_Type'Base; -- last index of new, expanded array | |
1128 | Dst : Elements_Access; -- new, expanded internal array | |
4c2d6a70 AC |
1129 | |
1130 | begin | |
e9f97e79 AC |
1131 | if Checks then |
1132 | -- As a precondition on the generic actual Index_Type, the base type | |
1133 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
1134 | -- that Container.Last assumes when the vector is empty. However, we | |
1135 | -- do not allow that as the value for Index when specifying where the | |
1136 | -- new items should be inserted, so we must manually check. (That the | |
1137 | -- user is allowed to specify the value at all here is a consequence | |
1138 | -- of the declaration of the Extended_Index subtype, which includes | |
1139 | -- the values in the base range that immediately precede and | |
1140 | -- immediately follow the values in the Index_Type.) | |
5bec9717 | 1141 | |
e9f97e79 AC |
1142 | if Before < Index_Type'First then |
1143 | raise Constraint_Error with | |
1144 | "Before index is out of range (too small)"; | |
1145 | end if; | |
8704d4b3 | 1146 | |
e9f97e79 AC |
1147 | -- We do allow a value greater than Container.Last to be specified as |
1148 | -- the Index, but only if it's immediately greater. This allows for | |
1149 | -- the case of appending items to the back end of the vector. (It is | |
1150 | -- assumed that specifying an index value greater than Last + 1 | |
1151 | -- indicates some deeper flaw in the caller's algorithm, so that case | |
1152 | -- is treated as a proper error.) | |
1153 | ||
1154 | if Before > Container.Last + 1 then | |
1155 | raise Constraint_Error with | |
1156 | "Before index is out of range (too large)"; | |
1157 | end if; | |
8704d4b3 | 1158 | end if; |
4c2d6a70 | 1159 | |
5bec9717 AC |
1160 | -- We treat inserting 0 items into the container as a no-op, even when |
1161 | -- the container is busy, so we simply return. | |
1162 | ||
4c2d6a70 AC |
1163 | if Count = 0 then |
1164 | return; | |
1165 | end if; | |
1166 | ||
5bec9717 AC |
1167 | -- There are two constraints we need to satisfy. The first constraint is |
1168 | -- that a container cannot have more than Count_Type'Last elements, so | |
0b5b2bbc | 1169 | -- we must check the sum of the current length and the insertion count. |
e9f97e79 AC |
1170 | -- Note: we cannot simply add these values, because of the possibility |
1171 | -- of overflow. | |
8704d4b3 | 1172 | |
e9f97e79 | 1173 | if Checks and then Old_Length > Count_Type'Last - Count then |
5bec9717 AC |
1174 | raise Constraint_Error with "Count is out of range"; |
1175 | end if; | |
dc6b9ba2 | 1176 | |
5bec9717 AC |
1177 | -- It is now safe compute the length of the new vector, without fear of |
1178 | -- overflow. | |
d43d5ef7 | 1179 | |
5bec9717 AC |
1180 | New_Length := Old_Length + Count; |
1181 | ||
1182 | -- The second constraint is that the new Last index value cannot exceed | |
1183 | -- Index_Type'Last. In each branch below, we calculate the maximum | |
1184 | -- length (computed from the range of values in Index_Type), and then | |
1185 | -- compare the new length to the maximum length. If the new length is | |
1186 | -- acceptable, then we compute the new last index from that. | |
1187 | ||
e9f97e79 | 1188 | if Index_Type'Base'Last >= Count_Type_Last then |
0b5b2bbc | 1189 | |
5bec9717 AC |
1190 | -- We have to handle the case when there might be more values in the |
1191 | -- range of Index_Type than in the range of Count_Type. | |
1192 | ||
1193 | if Index_Type'First <= 0 then | |
0b5b2bbc | 1194 | |
5bec9717 AC |
1195 | -- We know that No_Index (the same as Index_Type'First - 1) is |
1196 | -- less than 0, so it is safe to compute the following sum without | |
1197 | -- fear of overflow. | |
1198 | ||
1199 | Index := No_Index + Index_Type'Base (Count_Type'Last); | |
1200 | ||
1201 | if Index <= Index_Type'Last then | |
0b5b2bbc | 1202 | |
5bec9717 AC |
1203 | -- We have determined that range of Index_Type has at least as |
1204 | -- many values as in Count_Type, so Count_Type'Last is the | |
1205 | -- maximum number of items that are allowed. | |
1206 | ||
1207 | Max_Length := Count_Type'Last; | |
1208 | ||
1209 | else | |
1210 | -- The range of Index_Type has fewer values than in Count_Type, | |
1211 | -- so the maximum number of items is computed from the range of | |
1212 | -- the Index_Type. | |
1213 | ||
1214 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1215 | end if; | |
1216 | ||
1217 | else | |
1218 | -- No_Index is equal or greater than 0, so we can safely compute | |
1219 | -- the difference without fear of overflow (which we would have to | |
1220 | -- worry about if No_Index were less than 0, but that case is | |
1221 | -- handled above). | |
1222 | ||
e9f97e79 | 1223 | if Index_Type'Last - No_Index >= Count_Type_Last then |
7b56a91b AC |
1224 | -- We have determined that range of Index_Type has at least as |
1225 | -- many values as in Count_Type, so Count_Type'Last is the | |
1226 | -- maximum number of items that are allowed. | |
1227 | ||
1228 | Max_Length := Count_Type'Last; | |
1229 | ||
1230 | else | |
1231 | -- The range of Index_Type has fewer values than in Count_Type, | |
1232 | -- so the maximum number of items is computed from the range of | |
1233 | -- the Index_Type. | |
1234 | ||
1235 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1236 | end if; | |
dc6b9ba2 MH |
1237 | end if; |
1238 | ||
5bec9717 | 1239 | elsif Index_Type'First <= 0 then |
0b5b2bbc | 1240 | |
5bec9717 AC |
1241 | -- We know that No_Index (the same as Index_Type'First - 1) is less |
1242 | -- than 0, so it is safe to compute the following sum without fear of | |
1243 | -- overflow. | |
dc6b9ba2 | 1244 | |
5bec9717 AC |
1245 | J := Count_Type'Base (No_Index) + Count_Type'Last; |
1246 | ||
1247 | if J <= Count_Type'Base (Index_Type'Last) then | |
0b5b2bbc | 1248 | |
5bec9717 AC |
1249 | -- We have determined that range of Index_Type has at least as |
1250 | -- many values as in Count_Type, so Count_Type'Last is the maximum | |
1251 | -- number of items that are allowed. | |
1252 | ||
1253 | Max_Length := Count_Type'Last; | |
1254 | ||
1255 | else | |
1256 | -- The range of Index_Type has fewer values than Count_Type does, | |
1257 | -- so the maximum number of items is computed from the range of | |
1258 | -- the Index_Type. | |
1259 | ||
1260 | Max_Length := | |
1261 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
d43d5ef7 MH |
1262 | end if; |
1263 | ||
5bec9717 AC |
1264 | else |
1265 | -- No_Index is equal or greater than 0, so we can safely compute the | |
1266 | -- difference without fear of overflow (which we would have to worry | |
1267 | -- about if No_Index were less than 0, but that case is handled | |
1268 | -- above). | |
8704d4b3 | 1269 | |
5bec9717 AC |
1270 | Max_Length := |
1271 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
1272 | end if; | |
1273 | ||
1274 | -- We have just computed the maximum length (number of items). We must | |
1275 | -- now compare the requested length to the maximum length, as we do not | |
1276 | -- allow a vector expand beyond the maximum (because that would create | |
1277 | -- an internal array with a last index value greater than | |
1278 | -- Index_Type'Last, with no way to index those elements). | |
1279 | ||
e9f97e79 | 1280 | if Checks and then New_Length > Max_Length then |
5bec9717 AC |
1281 | raise Constraint_Error with "Count is out of range"; |
1282 | end if; | |
1283 | ||
1284 | -- New_Last is the last index value of the items in the container after | |
1285 | -- insertion. Use the wider of Index_Type'Base and Count_Type'Base to | |
1286 | -- compute its value from the New_Length. | |
1287 | ||
e9f97e79 | 1288 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1289 | New_Last := No_Index + Index_Type'Base (New_Length); |
5bec9717 AC |
1290 | else |
1291 | New_Last := Index_Type'Base (Count_Type'Base (No_Index) + New_Length); | |
4c2d6a70 AC |
1292 | end if; |
1293 | ||
8704d4b3 | 1294 | if Container.Elements = null then |
5bec9717 AC |
1295 | pragma Assert (Container.Last = No_Index); |
1296 | ||
1297 | -- This is the simplest case, with which we must always begin: we're | |
1298 | -- inserting items into an empty vector that hasn't allocated an | |
1299 | -- internal array yet. Note that we don't need to check the busy bit | |
1300 | -- here, because an empty container cannot be busy. | |
1301 | ||
1302 | -- In an indefinite vector, elements are allocated individually, and | |
1303 | -- stored as access values on the internal array (the length of which | |
1304 | -- represents the vector "capacity"), which is separately allocated. | |
1305 | ||
f97ccb3a | 1306 | Container.Elements := new Elements_Type (New_Last); |
d43d5ef7 | 1307 | |
5bec9717 AC |
1308 | -- The element backbone has been successfully allocated, so now we |
1309 | -- allocate the elements. | |
1310 | ||
1311 | for Idx in Container.Elements.EA'Range loop | |
0b5b2bbc | 1312 | |
5bec9717 AC |
1313 | -- In order to preserve container invariants, we always attempt |
1314 | -- the element allocation first, before setting the Last index | |
1315 | -- value, in case the allocation fails (either because there is no | |
1316 | -- storage available, or because element initialization fails). | |
1317 | ||
50878404 | 1318 | declare |
50878404 AC |
1319 | -- The element allocator may need an accessibility check in the |
1320 | -- case actual type is class-wide or has access discriminants | |
1321 | -- (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
1322 | |
1323 | pragma Unsuppress (Accessibility_Check); | |
1324 | ||
50878404 AC |
1325 | begin |
1326 | Container.Elements.EA (Idx) := new Element_Type'(New_Item); | |
1327 | end; | |
5bec9717 AC |
1328 | |
1329 | -- The allocation of the element succeeded, so it is now safe to | |
1330 | -- update the Last index, restoring container invariants. | |
1331 | ||
1332 | Container.Last := Idx; | |
d43d5ef7 | 1333 | end loop; |
4c2d6a70 | 1334 | |
8704d4b3 MH |
1335 | return; |
1336 | end if; | |
1337 | ||
5bec9717 AC |
1338 | -- The tampering bits exist to prevent an item from being harmfully |
1339 | -- manipulated while it is being visited. Query, Update, and Iterate | |
1340 | -- increment the busy count on entry, and decrement the count on | |
1341 | -- exit. Insert checks the count to determine whether it is being called | |
1342 | -- while the associated callback procedure is executing. | |
1343 | ||
e9f97e79 | 1344 | TC_Check (Container.TC); |
5bec9717 AC |
1345 | |
1346 | if New_Length <= Container.Elements.EA'Length then | |
0b5b2bbc | 1347 | |
5bec9717 AC |
1348 | -- In this case, we're inserting elements into a vector that has |
1349 | -- already allocated an internal array, and the existing array has | |
1350 | -- enough unused storage for the new items. | |
1351 | ||
8704d4b3 | 1352 | declare |
f97ccb3a | 1353 | E : Elements_Array renames Container.Elements.EA; |
5bec9717 | 1354 | K : Index_Type'Base; |
dc6b9ba2 | 1355 | |
8704d4b3 | 1356 | begin |
5bec9717 | 1357 | if Before > Container.Last then |
0b5b2bbc | 1358 | |
5bec9717 AC |
1359 | -- The new items are being appended to the vector, so no |
1360 | -- sliding of existing elements is required. | |
d43d5ef7 | 1361 | |
5bec9717 | 1362 | for Idx in Before .. New_Last loop |
0b5b2bbc | 1363 | |
5bec9717 AC |
1364 | -- In order to preserve container invariants, we always |
1365 | -- attempt the element allocation first, before setting the | |
1366 | -- Last index value, in case the allocation fails (either | |
1367 | -- because there is no storage available, or because element | |
1368 | -- initialization fails). | |
d43d5ef7 | 1369 | |
50878404 | 1370 | declare |
50878404 AC |
1371 | -- The element allocator may need an accessibility check |
1372 | -- in case the actual type is class-wide or has access | |
1373 | -- discriminants (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
1374 | |
1375 | pragma Unsuppress (Accessibility_Check); | |
1376 | ||
50878404 AC |
1377 | begin |
1378 | E (Idx) := new Element_Type'(New_Item); | |
1379 | end; | |
5bec9717 AC |
1380 | |
1381 | -- The allocation of the element succeeded, so it is now | |
1382 | -- safe to update the Last index, restoring container | |
1383 | -- invariants. | |
1384 | ||
1385 | Container.Last := Idx; | |
1386 | end loop; | |
1387 | ||
1388 | else | |
1389 | -- The new items are being inserted before some existing | |
1390 | -- elements, so we must slide the existing elements up to their | |
1391 | -- new home. We use the wider of Index_Type'Base and | |
1392 | -- Count_Type'Base as the type for intermediate index values. | |
8704d4b3 | 1393 | |
e9f97e79 | 1394 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1395 | Index := Before + Index_Type'Base (Count); |
5bec9717 AC |
1396 | else |
1397 | Index := Index_Type'Base (Count_Type'Base (Before) + Count); | |
1398 | end if; | |
1399 | ||
1400 | -- The new items are being inserted in the middle of the array, | |
1401 | -- in the range [Before, Index). Copy the existing elements to | |
1402 | -- the end of the array, to make room for the new items. | |
1403 | ||
1404 | E (Index .. New_Last) := E (Before .. Container.Last); | |
1405 | Container.Last := New_Last; | |
1406 | ||
1407 | -- We have copied the existing items up to the end of the | |
1408 | -- array, to make room for the new items in the middle of | |
1409 | -- the array. Now we actually allocate the new items. | |
1410 | ||
1411 | -- Note: initialize K outside loop to make it clear that | |
1412 | -- K always has a value if the exception handler triggers. | |
1413 | ||
1414 | K := Before; | |
29ba9f52 | 1415 | |
50878404 | 1416 | declare |
50878404 AC |
1417 | -- The element allocator may need an accessibility check in |
1418 | -- the case the actual type is class-wide or has access | |
1419 | -- discriminants (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
1420 | |
1421 | pragma Unsuppress (Accessibility_Check); | |
1422 | ||
8704d4b3 | 1423 | begin |
5bec9717 AC |
1424 | while K < Index loop |
1425 | E (K) := new Element_Type'(New_Item); | |
1426 | K := K + 1; | |
1427 | end loop; | |
3acdda2d | 1428 | |
5bec9717 AC |
1429 | exception |
1430 | when others => | |
3acdda2d | 1431 | |
5bec9717 AC |
1432 | -- Values in the range [Before, K) were successfully |
1433 | -- allocated, but values in the range [K, Index) are | |
1434 | -- stale (these array positions contain copies of the | |
1435 | -- old items, that did not get assigned a new item, | |
1436 | -- because the allocation failed). We must finish what | |
1437 | -- we started by clearing out all of the stale values, | |
1438 | -- leaving a "hole" in the middle of the array. | |
3acdda2d | 1439 | |
5bec9717 AC |
1440 | E (K .. Index - 1) := (others => null); |
1441 | raise; | |
8704d4b3 | 1442 | end; |
d43d5ef7 | 1443 | end if; |
8704d4b3 | 1444 | end; |
4c2d6a70 | 1445 | |
4c2d6a70 AC |
1446 | return; |
1447 | end if; | |
1448 | ||
5bec9717 AC |
1449 | -- In this case, we're inserting elements into a vector that has already |
1450 | -- allocated an internal array, but the existing array does not have | |
1451 | -- enough storage, so we must allocate a new, longer array. In order to | |
1452 | -- guarantee that the amortized insertion cost is O(1), we always | |
1453 | -- allocate an array whose length is some power-of-two factor of the | |
1454 | -- current array length. (The new array cannot have a length less than | |
1455 | -- the New_Length of the container, but its last index value cannot be | |
1456 | -- greater than Index_Type'Last.) | |
1457 | ||
1458 | New_Capacity := Count_Type'Max (1, Container.Elements.EA'Length); | |
1459 | while New_Capacity < New_Length loop | |
1460 | if New_Capacity > Count_Type'Last / 2 then | |
1461 | New_Capacity := Count_Type'Last; | |
1462 | exit; | |
1463 | end if; | |
3acdda2d | 1464 | |
5bec9717 AC |
1465 | New_Capacity := 2 * New_Capacity; |
1466 | end loop; | |
4c2d6a70 | 1467 | |
5bec9717 | 1468 | if New_Capacity > Max_Length then |
0b5b2bbc | 1469 | |
5bec9717 AC |
1470 | -- We have reached the limit of capacity, so no further expansion |
1471 | -- will occur. (This is not a problem, as there is never a need to | |
1472 | -- have more capacity than the maximum container length.) | |
4c2d6a70 | 1473 | |
5bec9717 AC |
1474 | New_Capacity := Max_Length; |
1475 | end if; | |
4c2d6a70 | 1476 | |
5bec9717 AC |
1477 | -- We have computed the length of the new internal array (and this is |
1478 | -- what "vector capacity" means), so use that to compute its last index. | |
4c2d6a70 | 1479 | |
e9f97e79 | 1480 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1481 | Dst_Last := No_Index + Index_Type'Base (New_Capacity); |
5bec9717 AC |
1482 | else |
1483 | Dst_Last := | |
1484 | Index_Type'Base (Count_Type'Base (No_Index) + New_Capacity); | |
1485 | end if; | |
4c2d6a70 | 1486 | |
5bec9717 AC |
1487 | -- Now we allocate the new, longer internal array. If the allocation |
1488 | -- fails, we have not changed any container state, so no side-effect | |
1489 | -- will occur as a result of propagating the exception. | |
dc6b9ba2 | 1490 | |
5bec9717 | 1491 | Dst := new Elements_Type (Dst_Last); |
4c2d6a70 | 1492 | |
5bec9717 AC |
1493 | -- We have our new internal array. All that needs to be done now is to |
1494 | -- copy the existing items (if any) from the old array (the "source" | |
1495 | -- array) to the new array (the "destination" array), and then | |
1496 | -- deallocate the old array. | |
4c2d6a70 | 1497 | |
5bec9717 AC |
1498 | declare |
1499 | Src : Elements_Access := Container.Elements; | |
4c2d6a70 | 1500 | |
5bec9717 AC |
1501 | begin |
1502 | Dst.EA (Index_Type'First .. Before - 1) := | |
1503 | Src.EA (Index_Type'First .. Before - 1); | |
4c2d6a70 | 1504 | |
5bec9717 | 1505 | if Before > Container.Last then |
0b5b2bbc | 1506 | |
5bec9717 AC |
1507 | -- The new items are being appended to the vector, so no |
1508 | -- sliding of existing elements is required. | |
4c2d6a70 | 1509 | |
2602b64e AC |
1510 | -- We have copied the elements from to the old source array to the |
1511 | -- new destination array, so we can now deallocate the old array. | |
4c2d6a70 | 1512 | |
d43d5ef7 | 1513 | Container.Elements := Dst; |
d43d5ef7 MH |
1514 | Free (Src); |
1515 | ||
5bec9717 AC |
1516 | -- Now we append the new items. |
1517 | ||
1518 | for Idx in Before .. New_Last loop | |
0b5b2bbc | 1519 | |
2602b64e AC |
1520 | -- In order to preserve container invariants, we always attempt |
1521 | -- the element allocation first, before setting the Last index | |
1522 | -- value, in case the allocation fails (either because there | |
1523 | -- is no storage available, or because element initialization | |
1524 | -- fails). | |
5bec9717 | 1525 | |
50878404 | 1526 | declare |
50878404 AC |
1527 | -- The element allocator may need an accessibility check in |
1528 | -- the case the actual type is class-wide or has access | |
1529 | -- discriminants (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
1530 | |
1531 | pragma Unsuppress (Accessibility_Check); | |
1532 | ||
50878404 AC |
1533 | begin |
1534 | Dst.EA (Idx) := new Element_Type'(New_Item); | |
1535 | end; | |
5bec9717 AC |
1536 | |
1537 | -- The allocation of the element succeeded, so it is now safe | |
1538 | -- to update the Last index, restoring container invariants. | |
1539 | ||
1540 | Container.Last := Idx; | |
d43d5ef7 | 1541 | end loop; |
4c2d6a70 | 1542 | |
5bec9717 AC |
1543 | else |
1544 | -- The new items are being inserted before some existing elements, | |
1545 | -- so we must slide the existing elements up to their new home. | |
4c2d6a70 | 1546 | |
e9f97e79 | 1547 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1548 | Index := Before + Index_Type'Base (Count); |
5bec9717 AC |
1549 | else |
1550 | Index := Index_Type'Base (Count_Type'Base (Before) + Count); | |
1551 | end if; | |
1552 | ||
1553 | Dst.EA (Index .. New_Last) := Src.EA (Before .. Container.Last); | |
1554 | ||
2602b64e AC |
1555 | -- We have copied the elements from to the old source array to the |
1556 | -- new destination array, so we can now deallocate the old array. | |
d43d5ef7 MH |
1557 | |
1558 | Container.Elements := Dst; | |
5bec9717 | 1559 | Container.Last := New_Last; |
d43d5ef7 MH |
1560 | Free (Src); |
1561 | ||
5bec9717 | 1562 | -- The new array has a range in the middle containing null access |
2602b64e | 1563 | -- values. Fill in that partition of the array with the new items. |
5bec9717 AC |
1564 | |
1565 | for Idx in Before .. Index - 1 loop | |
0b5b2bbc | 1566 | |
5bec9717 AC |
1567 | -- Note that container invariants have already been satisfied |
1568 | -- (in particular, the Last index value of the vector has | |
1569 | -- already been updated), so if this allocation fails we simply | |
1570 | -- let it propagate. | |
1571 | ||
50878404 | 1572 | declare |
50878404 AC |
1573 | -- The element allocator may need an accessibility check in |
1574 | -- the case the actual type is class-wide or has access | |
1575 | -- discriminants (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
1576 | |
1577 | pragma Unsuppress (Accessibility_Check); | |
1578 | ||
50878404 AC |
1579 | begin |
1580 | Dst.EA (Idx) := new Element_Type'(New_Item); | |
1581 | end; | |
d43d5ef7 | 1582 | end loop; |
5bec9717 AC |
1583 | end if; |
1584 | end; | |
8704d4b3 MH |
1585 | end Insert; |
1586 | ||
1587 | procedure Insert | |
1588 | (Container : in out Vector; | |
1589 | Before : Extended_Index; | |
1590 | New_Item : Vector) | |
1591 | is | |
1592 | N : constant Count_Type := Length (New_Item); | |
5bec9717 | 1593 | J : Index_Type'Base; |
4c2d6a70 | 1594 | |
4c2d6a70 | 1595 | begin |
5bec9717 AC |
1596 | -- Use Insert_Space to create the "hole" (the destination slice) into |
1597 | -- which we copy the source items. | |
4c2d6a70 | 1598 | |
5bec9717 | 1599 | Insert_Space (Container, Before, Count => N); |
4c2d6a70 | 1600 | |
8704d4b3 | 1601 | if N = 0 then |
0b5b2bbc | 1602 | |
5bec9717 AC |
1603 | -- There's nothing else to do here (vetting of parameters was |
1604 | -- performed already in Insert_Space), so we simply return. | |
1605 | ||
8704d4b3 MH |
1606 | return; |
1607 | end if; | |
4c2d6a70 | 1608 | |
5bec9717 | 1609 | if Container'Address /= New_Item'Address then |
0b5b2bbc | 1610 | |
5bec9717 AC |
1611 | -- This is the simple case. New_Item denotes an object different |
1612 | -- from Container, so there's nothing special we need to do to copy | |
1613 | -- the source items to their destination, because all of the source | |
1614 | -- items are contiguous. | |
1615 | ||
1616 | declare | |
1617 | subtype Src_Index_Subtype is Index_Type'Base range | |
1618 | Index_Type'First .. New_Item.Last; | |
1619 | ||
1620 | Src : Elements_Array renames | |
1621 | New_Item.Elements.EA (Src_Index_Subtype); | |
1622 | ||
1623 | Dst : Elements_Array renames Container.Elements.EA; | |
1624 | ||
1625 | Dst_Index : Index_Type'Base; | |
1626 | ||
1627 | begin | |
1628 | Dst_Index := Before - 1; | |
1629 | for Src_Index in Src'Range loop | |
1630 | Dst_Index := Dst_Index + 1; | |
1631 | ||
1632 | if Src (Src_Index) /= null then | |
1633 | Dst (Dst_Index) := new Element_Type'(Src (Src_Index).all); | |
1634 | end if; | |
1635 | end loop; | |
1636 | end; | |
1637 | ||
1638 | return; | |
1639 | end if; | |
1640 | ||
1641 | -- New_Item denotes the same object as Container, so an insertion has | |
1642 | -- potentially split the source items. The first source slice is | |
1643 | -- [Index_Type'First, Before), and the second source slice is | |
1644 | -- [J, Container.Last], where index value J is the first index of the | |
1645 | -- second slice. (J gets computed below, but only after we have | |
1646 | -- determined that the second source slice is non-empty.) The | |
1647 | -- destination slice is always the range [Before, J). We perform the | |
1648 | -- copy in two steps, using each of the two slices of the source items. | |
4c2d6a70 | 1649 | |
d43d5ef7 | 1650 | declare |
5bec9717 AC |
1651 | L : constant Index_Type'Base := Before - 1; |
1652 | ||
1653 | subtype Src_Index_Subtype is Index_Type'Base range | |
1654 | Index_Type'First .. L; | |
4c2d6a70 | 1655 | |
5bec9717 AC |
1656 | Src : Elements_Array renames |
1657 | Container.Elements.EA (Src_Index_Subtype); | |
4c2d6a70 | 1658 | |
5bec9717 | 1659 | Dst : Elements_Array renames Container.Elements.EA; |
4c2d6a70 | 1660 | |
5bec9717 | 1661 | Dst_Index : Index_Type'Base; |
4c2d6a70 | 1662 | |
d43d5ef7 | 1663 | begin |
5bec9717 AC |
1664 | -- We first copy the source items that precede the space we |
1665 | -- inserted. (If Before equals Index_Type'First, then this first | |
1666 | -- source slice will be empty, which is harmless.) | |
f97ccb3a | 1667 | |
5bec9717 AC |
1668 | Dst_Index := Before - 1; |
1669 | for Src_Index in Src'Range loop | |
1670 | Dst_Index := Dst_Index + 1; | |
8704d4b3 | 1671 | |
5bec9717 AC |
1672 | if Src (Src_Index) /= null then |
1673 | Dst (Dst_Index) := new Element_Type'(Src (Src_Index).all); | |
1674 | end if; | |
1675 | end loop; | |
4c2d6a70 | 1676 | |
5bec9717 | 1677 | if Src'Length = N then |
0b5b2bbc | 1678 | |
5bec9717 AC |
1679 | -- The new items were effectively appended to the container, so we |
1680 | -- have already copied all of the items that need to be copied. | |
1681 | -- We return early here, even though the source slice below is | |
1682 | -- empty (so the assignment would be harmless), because we want to | |
1683 | -- avoid computing J, which will overflow if J is greater than | |
1684 | -- Index_Type'Base'Last. | |
4c2d6a70 | 1685 | |
d43d5ef7 MH |
1686 | return; |
1687 | end if; | |
5bec9717 | 1688 | end; |
4c2d6a70 | 1689 | |
5bec9717 | 1690 | -- Index value J is the first index of the second source slice. (It is |
0b5b2bbc AC |
1691 | -- also 1 greater than the last index of the destination slice.) Note: |
1692 | -- avoid computing J if J is greater than Index_Type'Base'Last, in order | |
1693 | -- to avoid overflow. Prevent that by returning early above, immediately | |
1694 | -- after copying the first slice of the source, and determining that | |
1695 | -- this second slice of the source is empty. | |
4c2d6a70 | 1696 | |
e9f97e79 | 1697 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1698 | J := Before + Index_Type'Base (N); |
5bec9717 AC |
1699 | else |
1700 | J := Index_Type'Base (Count_Type'Base (Before) + N); | |
1701 | end if; | |
4c2d6a70 | 1702 | |
5bec9717 AC |
1703 | declare |
1704 | subtype Src_Index_Subtype is Index_Type'Base range | |
1705 | J .. Container.Last; | |
4c2d6a70 | 1706 | |
5bec9717 AC |
1707 | Src : Elements_Array renames |
1708 | Container.Elements.EA (Src_Index_Subtype); | |
4c2d6a70 | 1709 | |
5bec9717 | 1710 | Dst : Elements_Array renames Container.Elements.EA; |
4c2d6a70 | 1711 | |
5bec9717 | 1712 | Dst_Index : Index_Type'Base; |
4c2d6a70 | 1713 | |
5bec9717 | 1714 | begin |
0b5b2bbc AC |
1715 | -- We next copy the source items that follow the space we inserted. |
1716 | -- Index value Dst_Index is the first index of that portion of the | |
1717 | -- destination that receives this slice of the source. (For the | |
1718 | -- reasons given above, this slice is guaranteed to be non-empty.) | |
4c2d6a70 | 1719 | |
e9f97e79 | 1720 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 1721 | Dst_Index := J - Index_Type'Base (Src'Length); |
5bec9717 AC |
1722 | else |
1723 | Dst_Index := Index_Type'Base (Count_Type'Base (J) - Src'Length); | |
1724 | end if; | |
1725 | ||
1726 | for Src_Index in Src'Range loop | |
1727 | if Src (Src_Index) /= null then | |
1728 | Dst (Dst_Index) := new Element_Type'(Src (Src_Index).all); | |
1729 | end if; | |
1730 | ||
1731 | Dst_Index := Dst_Index + 1; | |
1732 | end loop; | |
d43d5ef7 | 1733 | end; |
8704d4b3 | 1734 | end Insert; |
4c2d6a70 | 1735 | |
8704d4b3 MH |
1736 | procedure Insert |
1737 | (Container : in out Vector; | |
1738 | Before : Cursor; | |
1739 | New_Item : Vector) | |
1740 | is | |
1741 | Index : Index_Type'Base; | |
4c2d6a70 | 1742 | |
8704d4b3 | 1743 | begin |
e9f97e79 | 1744 | if Checks and then Before.Container /= null |
ef992452 | 1745 | and then Before.Container /= Container'Unrestricted_Access |
8704d4b3 | 1746 | then |
dc6b9ba2 | 1747 | raise Program_Error with "Before cursor denotes wrong container"; |
4c2d6a70 AC |
1748 | end if; |
1749 | ||
8704d4b3 | 1750 | if Is_Empty (New_Item) then |
4c2d6a70 AC |
1751 | return; |
1752 | end if; | |
1753 | ||
2602b64e | 1754 | if Before.Container = null or else Before.Index > Container.Last then |
e9f97e79 | 1755 | if Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 MH |
1756 | raise Constraint_Error with |
1757 | "vector is already at its maximum length"; | |
d43d5ef7 MH |
1758 | end if; |
1759 | ||
1760 | Index := Container.Last + 1; | |
1761 | ||
8704d4b3 MH |
1762 | else |
1763 | Index := Before.Index; | |
1764 | end if; | |
4c2d6a70 | 1765 | |
8704d4b3 MH |
1766 | Insert (Container, Index, New_Item); |
1767 | end Insert; | |
4c2d6a70 | 1768 | |
8704d4b3 MH |
1769 | procedure Insert |
1770 | (Container : in out Vector; | |
1771 | Before : Cursor; | |
1772 | New_Item : Vector; | |
1773 | Position : out Cursor) | |
1774 | is | |
1775 | Index : Index_Type'Base; | |
4c2d6a70 | 1776 | |
4c2d6a70 | 1777 | begin |
e9f97e79 AC |
1778 | if Checks and then Before.Container /= null |
1779 | and then Before.Container /= Container'Unrestricted_Access | |
8704d4b3 | 1780 | then |
dc6b9ba2 | 1781 | raise Program_Error with "Before cursor denotes wrong container"; |
8704d4b3 | 1782 | end if; |
4c2d6a70 | 1783 | |
8704d4b3 | 1784 | if Is_Empty (New_Item) then |
2602b64e | 1785 | if Before.Container = null or else Before.Index > Container.Last then |
8704d4b3 | 1786 | Position := No_Element; |
4c2d6a70 | 1787 | else |
ef992452 | 1788 | Position := (Container'Unrestricted_Access, Before.Index); |
4c2d6a70 | 1789 | end if; |
4c2d6a70 | 1790 | |
4c2d6a70 AC |
1791 | return; |
1792 | end if; | |
1793 | ||
2602b64e | 1794 | if Before.Container = null or else Before.Index > Container.Last then |
e9f97e79 | 1795 | if Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 MH |
1796 | raise Constraint_Error with |
1797 | "vector is already at its maximum length"; | |
d43d5ef7 MH |
1798 | end if; |
1799 | ||
1800 | Index := Container.Last + 1; | |
1801 | ||
4c2d6a70 | 1802 | else |
8704d4b3 | 1803 | Index := Before.Index; |
4c2d6a70 AC |
1804 | end if; |
1805 | ||
8704d4b3 | 1806 | Insert (Container, Index, New_Item); |
4c2d6a70 | 1807 | |
e9f97e79 | 1808 | Position := (Container'Unrestricted_Access, Index); |
8704d4b3 | 1809 | end Insert; |
4c2d6a70 | 1810 | |
8704d4b3 MH |
1811 | procedure Insert |
1812 | (Container : in out Vector; | |
1813 | Before : Cursor; | |
1814 | New_Item : Element_Type; | |
1815 | Count : Count_Type := 1) | |
1816 | is | |
1817 | Index : Index_Type'Base; | |
4c2d6a70 AC |
1818 | |
1819 | begin | |
e9f97e79 | 1820 | if Checks and then Before.Container /= null |
ef992452 | 1821 | and then Before.Container /= Container'Unrestricted_Access |
8704d4b3 | 1822 | then |
dc6b9ba2 | 1823 | raise Program_Error with "Before cursor denotes wrong container"; |
4c2d6a70 AC |
1824 | end if; |
1825 | ||
8704d4b3 | 1826 | if Count = 0 then |
4c2d6a70 AC |
1827 | return; |
1828 | end if; | |
1829 | ||
2602b64e | 1830 | if Before.Container = null or else Before.Index > Container.Last then |
e9f97e79 | 1831 | if Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 MH |
1832 | raise Constraint_Error with |
1833 | "vector is already at its maximum length"; | |
d43d5ef7 MH |
1834 | end if; |
1835 | ||
1836 | Index := Container.Last + 1; | |
1837 | ||
8704d4b3 MH |
1838 | else |
1839 | Index := Before.Index; | |
4c2d6a70 AC |
1840 | end if; |
1841 | ||
8704d4b3 MH |
1842 | Insert (Container, Index, New_Item, Count); |
1843 | end Insert; | |
4c2d6a70 | 1844 | |
8704d4b3 MH |
1845 | procedure Insert |
1846 | (Container : in out Vector; | |
1847 | Before : Cursor; | |
1848 | New_Item : Element_Type; | |
1849 | Position : out Cursor; | |
1850 | Count : Count_Type := 1) | |
1851 | is | |
1852 | Index : Index_Type'Base; | |
4c2d6a70 AC |
1853 | |
1854 | begin | |
e9f97e79 | 1855 | if Checks and then Before.Container /= null |
ef992452 | 1856 | and then Before.Container /= Container'Unrestricted_Access |
8704d4b3 | 1857 | then |
dc6b9ba2 | 1858 | raise Program_Error with "Before cursor denotes wrong container"; |
8704d4b3 MH |
1859 | end if; |
1860 | ||
1861 | if Count = 0 then | |
e9f97e79 | 1862 | if Before.Container = null or else Before.Index > Container.Last then |
8704d4b3 MH |
1863 | Position := No_Element; |
1864 | else | |
ef992452 | 1865 | Position := (Container'Unrestricted_Access, Before.Index); |
8704d4b3 | 1866 | end if; |
4c2d6a70 | 1867 | |
4c2d6a70 AC |
1868 | return; |
1869 | end if; | |
1870 | ||
2602b64e | 1871 | if Before.Container = null or else Before.Index > Container.Last then |
e9f97e79 | 1872 | if Checks and then Container.Last = Index_Type'Last then |
dc6b9ba2 MH |
1873 | raise Constraint_Error with |
1874 | "vector is already at its maximum length"; | |
d43d5ef7 MH |
1875 | end if; |
1876 | ||
1877 | Index := Container.Last + 1; | |
1878 | ||
8704d4b3 MH |
1879 | else |
1880 | Index := Before.Index; | |
4c2d6a70 AC |
1881 | end if; |
1882 | ||
8704d4b3 | 1883 | Insert (Container, Index, New_Item, Count); |
4c2d6a70 | 1884 | |
ef992452 | 1885 | Position := (Container'Unrestricted_Access, Index); |
8704d4b3 | 1886 | end Insert; |
4c2d6a70 | 1887 | |
8704d4b3 MH |
1888 | ------------------ |
1889 | -- Insert_Space -- | |
1890 | ------------------ | |
4c2d6a70 | 1891 | |
8704d4b3 MH |
1892 | procedure Insert_Space |
1893 | (Container : in out Vector; | |
1894 | Before : Extended_Index; | |
1895 | Count : Count_Type := 1) | |
1896 | is | |
5bec9717 AC |
1897 | Old_Length : constant Count_Type := Container.Length; |
1898 | ||
1899 | Max_Length : Count_Type'Base; -- determined from range of Index_Type | |
1900 | New_Length : Count_Type'Base; -- sum of current length and Count | |
1901 | New_Last : Index_Type'Base; -- last index of vector after insertion | |
4c2d6a70 | 1902 | |
5bec9717 AC |
1903 | Index : Index_Type'Base; -- scratch for intermediate values |
1904 | J : Count_Type'Base; -- scratch | |
4c2d6a70 | 1905 | |
5bec9717 AC |
1906 | New_Capacity : Count_Type'Base; -- length of new, expanded array |
1907 | Dst_Last : Index_Type'Base; -- last index of new, expanded array | |
1908 | Dst : Elements_Access; -- new, expanded internal array | |
4c2d6a70 AC |
1909 | |
1910 | begin | |
e9f97e79 AC |
1911 | if Checks then |
1912 | -- As a precondition on the generic actual Index_Type, the base type | |
1913 | -- must include Index_Type'Pred (Index_Type'First); this is the value | |
1914 | -- that Container.Last assumes when the vector is empty. However, we | |
1915 | -- do not allow that as the value for Index when specifying where the | |
1916 | -- new items should be inserted, so we must manually check. (That the | |
1917 | -- user is allowed to specify the value at all here is a consequence | |
1918 | -- of the declaration of the Extended_Index subtype, which includes | |
1919 | -- the values in the base range that immediately precede and | |
1920 | -- immediately follow the values in the Index_Type.) | |
5bec9717 | 1921 | |
e9f97e79 AC |
1922 | if Before < Index_Type'First then |
1923 | raise Constraint_Error with | |
1924 | "Before index is out of range (too small)"; | |
1925 | end if; | |
4c2d6a70 | 1926 | |
e9f97e79 AC |
1927 | -- We do allow a value greater than Container.Last to be specified as |
1928 | -- the Index, but only if it's immediately greater. This allows for | |
1929 | -- the case of appending items to the back end of the vector. (It is | |
1930 | -- assumed that specifying an index value greater than Last + 1 | |
1931 | -- indicates some deeper flaw in the caller's algorithm, so that case | |
1932 | -- is treated as a proper error.) | |
1933 | ||
1934 | if Before > Container.Last + 1 then | |
1935 | raise Constraint_Error with | |
1936 | "Before index is out of range (too large)"; | |
1937 | end if; | |
8704d4b3 | 1938 | end if; |
4c2d6a70 | 1939 | |
5bec9717 AC |
1940 | -- We treat inserting 0 items into the container as a no-op, even when |
1941 | -- the container is busy, so we simply return. | |
1942 | ||
8704d4b3 MH |
1943 | if Count = 0 then |
1944 | return; | |
4c2d6a70 AC |
1945 | end if; |
1946 | ||
5bec9717 AC |
1947 | -- There are two constraints we need to satisfy. The first constraint is |
1948 | -- that a container cannot have more than Count_Type'Last elements, so | |
e9f97e79 AC |
1949 | -- we must check the sum of the current length and the insertion count. |
1950 | -- Note: we cannot simply add these values, because of the possibility | |
1951 | -- of overflow. | |
4c2d6a70 | 1952 | |
e9f97e79 | 1953 | if Checks and then Old_Length > Count_Type'Last - Count then |
5bec9717 AC |
1954 | raise Constraint_Error with "Count is out of range"; |
1955 | end if; | |
dc6b9ba2 | 1956 | |
5bec9717 AC |
1957 | -- It is now safe compute the length of the new vector, without fear of |
1958 | -- overflow. | |
d43d5ef7 | 1959 | |
5bec9717 AC |
1960 | New_Length := Old_Length + Count; |
1961 | ||
1962 | -- The second constraint is that the new Last index value cannot exceed | |
1963 | -- Index_Type'Last. In each branch below, we calculate the maximum | |
1964 | -- length (computed from the range of values in Index_Type), and then | |
1965 | -- compare the new length to the maximum length. If the new length is | |
1966 | -- acceptable, then we compute the new last index from that. | |
1967 | ||
e9f97e79 | 1968 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 AC |
1969 | -- We have to handle the case when there might be more values in the |
1970 | -- range of Index_Type than in the range of Count_Type. | |
1971 | ||
1972 | if Index_Type'First <= 0 then | |
0b5b2bbc | 1973 | |
5bec9717 AC |
1974 | -- We know that No_Index (the same as Index_Type'First - 1) is |
1975 | -- less than 0, so it is safe to compute the following sum without | |
1976 | -- fear of overflow. | |
1977 | ||
1978 | Index := No_Index + Index_Type'Base (Count_Type'Last); | |
1979 | ||
1980 | if Index <= Index_Type'Last then | |
0b5b2bbc | 1981 | |
5bec9717 AC |
1982 | -- We have determined that range of Index_Type has at least as |
1983 | -- many values as in Count_Type, so Count_Type'Last is the | |
1984 | -- maximum number of items that are allowed. | |
1985 | ||
1986 | Max_Length := Count_Type'Last; | |
1987 | ||
1988 | else | |
1989 | -- The range of Index_Type has fewer values than in Count_Type, | |
1990 | -- so the maximum number of items is computed from the range of | |
1991 | -- the Index_Type. | |
1992 | ||
1993 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
1994 | end if; | |
1995 | ||
1996 | else | |
1997 | -- No_Index is equal or greater than 0, so we can safely compute | |
1998 | -- the difference without fear of overflow (which we would have to | |
1999 | -- worry about if No_Index were less than 0, but that case is | |
2000 | -- handled above). | |
2001 | ||
e9f97e79 | 2002 | if Index_Type'Last - No_Index >= Count_Type_Last then |
7b56a91b AC |
2003 | -- We have determined that range of Index_Type has at least as |
2004 | -- many values as in Count_Type, so Count_Type'Last is the | |
2005 | -- maximum number of items that are allowed. | |
2006 | ||
2007 | Max_Length := Count_Type'Last; | |
2008 | ||
2009 | else | |
2010 | -- The range of Index_Type has fewer values than in Count_Type, | |
2011 | -- so the maximum number of items is computed from the range of | |
2012 | -- the Index_Type. | |
2013 | ||
2014 | Max_Length := Count_Type'Base (Index_Type'Last - No_Index); | |
2015 | end if; | |
dc6b9ba2 MH |
2016 | end if; |
2017 | ||
5bec9717 | 2018 | elsif Index_Type'First <= 0 then |
0b5b2bbc | 2019 | |
5bec9717 AC |
2020 | -- We know that No_Index (the same as Index_Type'First - 1) is less |
2021 | -- than 0, so it is safe to compute the following sum without fear of | |
2022 | -- overflow. | |
dc6b9ba2 | 2023 | |
5bec9717 AC |
2024 | J := Count_Type'Base (No_Index) + Count_Type'Last; |
2025 | ||
2026 | if J <= Count_Type'Base (Index_Type'Last) then | |
0b5b2bbc | 2027 | |
5bec9717 AC |
2028 | -- We have determined that range of Index_Type has at least as |
2029 | -- many values as in Count_Type, so Count_Type'Last is the maximum | |
2030 | -- number of items that are allowed. | |
2031 | ||
2032 | Max_Length := Count_Type'Last; | |
2033 | ||
2034 | else | |
2035 | -- The range of Index_Type has fewer values than Count_Type does, | |
2036 | -- so the maximum number of items is computed from the range of | |
2037 | -- the Index_Type. | |
2038 | ||
2039 | Max_Length := | |
2040 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
d43d5ef7 MH |
2041 | end if; |
2042 | ||
5bec9717 AC |
2043 | else |
2044 | -- No_Index is equal or greater than 0, so we can safely compute the | |
2045 | -- difference without fear of overflow (which we would have to worry | |
2046 | -- about if No_Index were less than 0, but that case is handled | |
2047 | -- above). | |
4c2d6a70 | 2048 | |
5bec9717 AC |
2049 | Max_Length := |
2050 | Count_Type'Base (Index_Type'Last) - Count_Type'Base (No_Index); | |
2051 | end if; | |
2052 | ||
2053 | -- We have just computed the maximum length (number of items). We must | |
2054 | -- now compare the requested length to the maximum length, as we do not | |
2055 | -- allow a vector expand beyond the maximum (because that would create | |
2056 | -- an internal array with a last index value greater than | |
2057 | -- Index_Type'Last, with no way to index those elements). | |
2058 | ||
e9f97e79 | 2059 | if Checks and then New_Length > Max_Length then |
5bec9717 AC |
2060 | raise Constraint_Error with "Count is out of range"; |
2061 | end if; | |
2062 | ||
2063 | -- New_Last is the last index value of the items in the container after | |
2064 | -- insertion. Use the wider of Index_Type'Base and Count_Type'Base to | |
2065 | -- compute its value from the New_Length. | |
2066 | ||
e9f97e79 | 2067 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 2068 | New_Last := No_Index + Index_Type'Base (New_Length); |
5bec9717 AC |
2069 | else |
2070 | New_Last := Index_Type'Base (Count_Type'Base (No_Index) + New_Length); | |
4c2d6a70 AC |
2071 | end if; |
2072 | ||
8704d4b3 | 2073 | if Container.Elements = null then |
5bec9717 AC |
2074 | pragma Assert (Container.Last = No_Index); |
2075 | ||
2076 | -- This is the simplest case, with which we must always begin: we're | |
2077 | -- inserting items into an empty vector that hasn't allocated an | |
2078 | -- internal array yet. Note that we don't need to check the busy bit | |
2079 | -- here, because an empty container cannot be busy. | |
2080 | ||
2081 | -- In an indefinite vector, elements are allocated individually, and | |
2082 | -- stored as access values on the internal array (the length of which | |
0b5b2bbc AC |
2083 | -- represents the vector "capacity"), which is separately allocated. |
2084 | -- We have no elements here (because we're inserting "space"), so all | |
2085 | -- we need to do is allocate the backbone. | |
5bec9717 | 2086 | |
f97ccb3a | 2087 | Container.Elements := new Elements_Type (New_Last); |
d43d5ef7 | 2088 | Container.Last := New_Last; |
5bec9717 | 2089 | |
8704d4b3 MH |
2090 | return; |
2091 | end if; | |
4c2d6a70 | 2092 | |
5bec9717 AC |
2093 | -- The tampering bits exist to prevent an item from being harmfully |
2094 | -- manipulated while it is being visited. Query, Update, and Iterate | |
0b5b2bbc AC |
2095 | -- increment the busy count on entry, and decrement the count on exit. |
2096 | -- Insert checks the count to determine whether it is being called while | |
2097 | -- the associated callback procedure is executing. | |
5bec9717 | 2098 | |
e9f97e79 | 2099 | TC_Check (Container.TC); |
5bec9717 AC |
2100 | |
2101 | if New_Length <= Container.Elements.EA'Length then | |
2602b64e AC |
2102 | |
2103 | -- In this case, we are inserting elements into a vector that has | |
5bec9717 AC |
2104 | -- already allocated an internal array, and the existing array has |
2105 | -- enough unused storage for the new items. | |
2106 | ||
8704d4b3 | 2107 | declare |
f97ccb3a | 2108 | E : Elements_Array renames Container.Elements.EA; |
d43d5ef7 | 2109 | |
8704d4b3 | 2110 | begin |
d43d5ef7 | 2111 | if Before <= Container.Last then |
0b5b2bbc | 2112 | |
5bec9717 | 2113 | -- The new space is being inserted before some existing |
2602b64e AC |
2114 | -- elements, so we must slide the existing elements up to |
2115 | -- their new home. We use the wider of Index_Type'Base and | |
5bec9717 | 2116 | -- Count_Type'Base as the type for intermediate index values. |
4c2d6a70 | 2117 | |
e9f97e79 | 2118 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 2119 | Index := Before + Index_Type'Base (Count); |
5bec9717 AC |
2120 | else |
2121 | Index := Index_Type'Base (Count_Type'Base (Before) + Count); | |
2122 | end if; | |
2123 | ||
2124 | E (Index .. New_Last) := E (Before .. Container.Last); | |
2125 | E (Before .. Index - 1) := (others => null); | |
d43d5ef7 | 2126 | end if; |
4c2d6a70 AC |
2127 | end; |
2128 | ||
d43d5ef7 | 2129 | Container.Last := New_Last; |
8704d4b3 | 2130 | return; |
4c2d6a70 AC |
2131 | end if; |
2132 | ||
5bec9717 AC |
2133 | -- In this case, we're inserting elements into a vector that has already |
2134 | -- allocated an internal array, but the existing array does not have | |
2135 | -- enough storage, so we must allocate a new, longer array. In order to | |
2136 | -- guarantee that the amortized insertion cost is O(1), we always | |
2137 | -- allocate an array whose length is some power-of-two factor of the | |
2138 | -- current array length. (The new array cannot have a length less than | |
2139 | -- the New_Length of the container, but its last index value cannot be | |
2140 | -- greater than Index_Type'Last.) | |
2141 | ||
2142 | New_Capacity := Count_Type'Max (1, Container.Elements.EA'Length); | |
2143 | while New_Capacity < New_Length loop | |
2144 | if New_Capacity > Count_Type'Last / 2 then | |
2145 | New_Capacity := Count_Type'Last; | |
2146 | exit; | |
2147 | end if; | |
4c2d6a70 | 2148 | |
5bec9717 AC |
2149 | New_Capacity := 2 * New_Capacity; |
2150 | end loop; | |
4c2d6a70 | 2151 | |
5bec9717 | 2152 | if New_Capacity > Max_Length then |
0b5b2bbc | 2153 | |
5bec9717 AC |
2154 | -- We have reached the limit of capacity, so no further expansion |
2155 | -- will occur. (This is not a problem, as there is never a need to | |
2156 | -- have more capacity than the maximum container length.) | |
4c2d6a70 | 2157 | |
5bec9717 AC |
2158 | New_Capacity := Max_Length; |
2159 | end if; | |
4c2d6a70 | 2160 | |
5bec9717 AC |
2161 | -- We have computed the length of the new internal array (and this is |
2162 | -- what "vector capacity" means), so use that to compute its last index. | |
dc6b9ba2 | 2163 | |
e9f97e79 | 2164 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 2165 | Dst_Last := No_Index + Index_Type'Base (New_Capacity); |
5bec9717 AC |
2166 | else |
2167 | Dst_Last := | |
2168 | Index_Type'Base (Count_Type'Base (No_Index) + New_Capacity); | |
2169 | end if; | |
dc6b9ba2 | 2170 | |
5bec9717 AC |
2171 | -- Now we allocate the new, longer internal array. If the allocation |
2172 | -- fails, we have not changed any container state, so no side-effect | |
2173 | -- will occur as a result of propagating the exception. | |
2174 | ||
2175 | Dst := new Elements_Type (Dst_Last); | |
2176 | ||
2177 | -- We have our new internal array. All that needs to be done now is to | |
2178 | -- copy the existing items (if any) from the old array (the "source" | |
2179 | -- array) to the new array (the "destination" array), and then | |
2180 | -- deallocate the old array. | |
4c2d6a70 | 2181 | |
8704d4b3 | 2182 | declare |
d43d5ef7 | 2183 | Src : Elements_Access := Container.Elements; |
4c2d6a70 | 2184 | |
8704d4b3 | 2185 | begin |
5bec9717 AC |
2186 | Dst.EA (Index_Type'First .. Before - 1) := |
2187 | Src.EA (Index_Type'First .. Before - 1); | |
4c2d6a70 | 2188 | |
5bec9717 | 2189 | if Before <= Container.Last then |
0b5b2bbc | 2190 | |
5bec9717 AC |
2191 | -- The new items are being inserted before some existing elements, |
2192 | -- so we must slide the existing elements up to their new home. | |
d43d5ef7 | 2193 | |
e9f97e79 | 2194 | if Index_Type'Base'Last >= Count_Type_Last then |
5bec9717 | 2195 | Index := Before + Index_Type'Base (Count); |
5bec9717 AC |
2196 | else |
2197 | Index := Index_Type'Base (Count_Type'Base (Before) + Count); | |
2198 | end if; | |
d43d5ef7 | 2199 | |
5bec9717 | 2200 | Dst.EA (Index .. New_Last) := Src.EA (Before .. Container.Last); |
d43d5ef7 | 2201 | end if; |
4c2d6a70 | 2202 | |
5bec9717 AC |
2203 | -- We have copied the elements from to the old, source array to the |
2204 | -- new, destination array, so we can now restore invariants, and | |
2205 | -- deallocate the old array. | |
2206 | ||
8704d4b3 MH |
2207 | Container.Elements := Dst; |
2208 | Container.Last := New_Last; | |
d43d5ef7 | 2209 | Free (Src); |
4c2d6a70 | 2210 | end; |
8704d4b3 | 2211 | end Insert_Space; |
4c2d6a70 | 2212 | |
8704d4b3 MH |
2213 | procedure Insert_Space |
2214 | (Container : in out Vector; | |
2215 | Before : Cursor; | |
2216 | Position : out Cursor; | |
2217 | Count : Count_Type := 1) | |
2218 | is | |
2219 | Index : Index_Type'Base; | |
2220 | ||
2221 | begin | |
e9f97e79 | 2222 | if Checks and then Before.Container /= null |
ef992452 | 2223 | and then Before.Container /= Container'Unrestricted_Access |
8704d4b3 | 2224 | then |
dc6b9ba2 | 2225 | raise Program_Error with "Before cursor denotes wrong container"; |
8704d4b3 | 2226 | end if; |
4c2d6a70 | 2227 | |
8704d4b3 | 2228 | if Count = 0 then |
2602b64e | 2229 | if Before.Container = null or else Before.Index > Container.Last then |
8704d4b3 MH |
2230 | Position := No_Element; |
2231 | else | |
ef992452 | 2232 | Position := (Container'Unrestricted_Access, Before.Index); |
8704d4b3 | 2233 | end if; |
4c2d6a70 | 2234 | |
8704d4b3 MH |
2235 | return; |
2236 | end if; | |
4c2d6a70 | 2237 | |
e9f97e79 AC |
2238 | if Before.Container = null or else Before.Index > Container.Last then |
2239 | if Checks and then Container.Last = Index_Type'Last then | |
dc6b9ba2 MH |
2240 | raise Constraint_Error with |
2241 | "vector is already at its maximum length"; | |
d43d5ef7 MH |
2242 | end if; |
2243 | ||
2244 | Index := Container.Last + 1; | |
2245 | ||
8704d4b3 MH |
2246 | else |
2247 | Index := Before.Index; | |
2248 | end if; | |
4c2d6a70 | 2249 | |
8704d4b3 | 2250 | Insert_Space (Container, Index, Count); |
4c2d6a70 | 2251 | |
e9f97e79 | 2252 | Position := (Container'Unrestricted_Access, Index); |
8704d4b3 MH |
2253 | end Insert_Space; |
2254 | ||
2255 | -------------- | |
2256 | -- Is_Empty -- | |
2257 | -------------- | |
2258 | ||
2259 | function Is_Empty (Container : Vector) return Boolean is | |
4c2d6a70 | 2260 | begin |
8704d4b3 MH |
2261 | return Container.Last < Index_Type'First; |
2262 | end Is_Empty; | |
4c2d6a70 | 2263 | |
8704d4b3 MH |
2264 | ------------- |
2265 | -- Iterate -- | |
2266 | ------------- | |
2267 | ||
2268 | procedure Iterate | |
2269 | (Container : Vector; | |
0ae9f22f | 2270 | Process : not null access procedure (Position : Cursor)) |
8704d4b3 | 2271 | is |
e9f97e79 | 2272 | Busy : With_Busy (Container.TC'Unrestricted_Access); |
8704d4b3 | 2273 | begin |
e9f97e79 AC |
2274 | for Indx in Index_Type'First .. Container.Last loop |
2275 | Process (Cursor'(Container'Unrestricted_Access, Indx)); | |
2276 | end loop; | |
8704d4b3 | 2277 | end Iterate; |
4c2d6a70 | 2278 | |
e9f97e79 AC |
2279 | function Iterate |
2280 | (Container : Vector) | |
e8bd500e | 2281 | return Vector_Iterator_Interfaces.Reversible_Iterator'Class |
3e24afaa | 2282 | is |
e8bd500e | 2283 | V : constant Vector_Access := Container'Unrestricted_Access; |
3e24afaa | 2284 | begin |
e8bd500e AC |
2285 | -- The value of its Index component influences the behavior of the First |
2286 | -- and Last selector functions of the iterator object. When the Index | |
2287 | -- component is No_Index (as is the case here), this means the iterator | |
2288 | -- object was constructed without a start expression. This is a complete | |
2289 | -- iterator, meaning that the iteration starts from the (logical) | |
2290 | -- beginning of the sequence of items. | |
2291 | ||
2292 | -- Note: For a forward iterator, Container.First is the beginning, and | |
2293 | -- for a reverse iterator, Container.Last is the beginning. | |
2294 | ||
ef992452 | 2295 | return It : constant Iterator := |
15f0f591 AC |
2296 | (Limited_Controlled with |
2297 | Container => V, | |
2298 | Index => No_Index) | |
ef992452 | 2299 | do |
e9f97e79 | 2300 | Busy (Container.TC'Unrestricted_Access.all); |
ef992452 | 2301 | end return; |
3e24afaa AC |
2302 | end Iterate; |
2303 | ||
690943fc RD |
2304 | function Iterate |
2305 | (Container : Vector; | |
2306 | Start : Cursor) | |
e8bd500e | 2307 | return Vector_Iterator_Interfaces.Reversible_Iterator'Class |
3e24afaa | 2308 | is |
e8bd500e | 2309 | V : constant Vector_Access := Container'Unrestricted_Access; |
3e24afaa | 2310 | begin |
e8bd500e AC |
2311 | -- It was formerly the case that when Start = No_Element, the partial |
2312 | -- iterator was defined to behave the same as for a complete iterator, | |
2313 | -- and iterate over the entire sequence of items. However, those | |
2314 | -- semantics were unintuitive and arguably error-prone (it is too easy | |
2315 | -- to accidentally create an endless loop), and so they were changed, | |
2316 | -- per the ARG meeting in Denver on 2011/11. However, there was no | |
2317 | -- consensus about what positive meaning this corner case should have, | |
2318 | -- and so it was decided to simply raise an exception. This does imply, | |
2319 | -- however, that it is not possible to use a partial iterator to specify | |
2320 | -- an empty sequence of items. | |
2321 | ||
e9f97e79 AC |
2322 | if Checks then |
2323 | if Start.Container = null then | |
2324 | raise Constraint_Error with | |
2325 | "Start position for iterator equals No_Element"; | |
2326 | end if; | |
e8bd500e | 2327 | |
e9f97e79 AC |
2328 | if Start.Container /= V then |
2329 | raise Program_Error with | |
2330 | "Start cursor of Iterate designates wrong vector"; | |
2331 | end if; | |
e8bd500e | 2332 | |
e9f97e79 AC |
2333 | if Start.Index > V.Last then |
2334 | raise Constraint_Error with | |
2335 | "Start position for iterator equals No_Element"; | |
2336 | end if; | |
e8bd500e AC |
2337 | end if; |
2338 | ||
2339 | -- The value of its Index component influences the behavior of the First | |
2340 | -- and Last selector functions of the iterator object. When the Index | |
2341 | -- component is not No_Index (as is the case here), it means that this | |
2342 | -- is a partial iteration, over a subset of the complete sequence of | |
2343 | -- items. The iterator object was constructed with a start expression, | |
2344 | -- indicating the position from which the iteration begins. Note that | |
fe58fea7 AC |
2345 | -- the start position has the same value irrespective of whether this |
2346 | -- is a forward or reverse iteration. | |
e8bd500e | 2347 | |
ef992452 | 2348 | return It : constant Iterator := |
15f0f591 AC |
2349 | (Limited_Controlled with |
2350 | Container => V, | |
2351 | Index => Start.Index) | |
ef992452 | 2352 | do |
e9f97e79 | 2353 | Busy (Container.TC'Unrestricted_Access.all); |
ef992452 | 2354 | end return; |
3e24afaa AC |
2355 | end Iterate; |
2356 | ||
8704d4b3 MH |
2357 | ---------- |
2358 | -- Last -- | |
2359 | ---------- | |
4c2d6a70 | 2360 | |
8704d4b3 | 2361 | function Last (Container : Vector) return Cursor is |
4c2d6a70 | 2362 | begin |
8704d4b3 | 2363 | if Is_Empty (Container) then |
4c2d6a70 AC |
2364 | return No_Element; |
2365 | end if; | |
2366 | ||
ef992452 | 2367 | return (Container'Unrestricted_Access, Container.Last); |
8704d4b3 | 2368 | end Last; |
4c2d6a70 | 2369 | |
3e24afaa | 2370 | function Last (Object : Iterator) return Cursor is |
3e24afaa | 2371 | begin |
e8bd500e AC |
2372 | -- The value of the iterator object's Index component influences the |
2373 | -- behavior of the Last (and First) selector function. | |
2374 | ||
fe58fea7 AC |
2375 | -- When the Index component is No_Index, this means the iterator |
2376 | -- object was constructed without a start expression, in which case the | |
e8bd500e AC |
2377 | -- (reverse) iteration starts from the (logical) beginning of the entire |
2378 | -- sequence (corresponding to Container.Last, for a reverse iterator). | |
2379 | ||
fe58fea7 AC |
2380 | -- Otherwise, this is iteration over a partial sequence of items. |
2381 | -- When the Index component is not No_Index, the iterator object was | |
2382 | -- constructed with a start expression, that specifies the position | |
2383 | -- from which the (reverse) partial iteration begins. | |
e8bd500e AC |
2384 | |
2385 | if Object.Index = No_Index then | |
2386 | return Last (Object.Container.all); | |
2387 | else | |
2388 | return Cursor'(Object.Container, Object.Index); | |
2389 | end if; | |
3e24afaa AC |
2390 | end Last; |
2391 | ||
e9f97e79 | 2392 | ------------------ |
8704d4b3 MH |
2393 | -- Last_Element -- |
2394 | ------------------ | |
4c2d6a70 | 2395 | |
8704d4b3 | 2396 | function Last_Element (Container : Vector) return Element_Type is |
4c2d6a70 | 2397 | begin |
e9f97e79 | 2398 | if Checks and then Container.Last = No_Index then |
f97ccb3a BD |
2399 | raise Constraint_Error with "Container is empty"; |
2400 | end if; | |
2401 | ||
2402 | declare | |
2403 | EA : constant Element_Access := | |
2602b64e | 2404 | Container.Elements.EA (Container.Last); |
f97ccb3a | 2405 | begin |
e9f97e79 | 2406 | if Checks and then EA = null then |
f97ccb3a | 2407 | raise Constraint_Error with "last element is empty"; |
2602b64e AC |
2408 | else |
2409 | return EA.all; | |
f97ccb3a | 2410 | end if; |
f97ccb3a | 2411 | end; |
8704d4b3 | 2412 | end Last_Element; |
4c2d6a70 | 2413 | |
8704d4b3 MH |
2414 | ---------------- |
2415 | -- Last_Index -- | |
2416 | ---------------- | |
4c2d6a70 | 2417 | |
8704d4b3 MH |
2418 | function Last_Index (Container : Vector) return Extended_Index is |
2419 | begin | |
2420 | return Container.Last; | |
2421 | end Last_Index; | |
4c2d6a70 | 2422 | |
8704d4b3 MH |
2423 | ------------ |
2424 | -- Length -- | |
2425 | ------------ | |
4c2d6a70 | 2426 | |
8704d4b3 | 2427 | function Length (Container : Vector) return Count_Type is |
5bec9717 AC |
2428 | L : constant Index_Type'Base := Container.Last; |
2429 | F : constant Index_Type := Index_Type'First; | |
d43d5ef7 | 2430 | |
4c2d6a70 | 2431 | begin |
5bec9717 AC |
2432 | -- The base range of the index type (Index_Type'Base) might not include |
2433 | -- all values for length (Count_Type). Contrariwise, the index type | |
2434 | -- might include values outside the range of length. Hence we use | |
2435 | -- whatever type is wider for intermediate values when calculating | |
2436 | -- length. Note that no matter what the index type is, the maximum | |
2437 | -- length to which a vector is allowed to grow is always the minimum | |
2438 | -- of Count_Type'Last and (IT'Last - IT'First + 1). | |
2439 | ||
2440 | -- For example, an Index_Type with range -127 .. 127 is only guaranteed | |
2441 | -- to have a base range of -128 .. 127, but the corresponding vector | |
2442 | -- would have lengths in the range 0 .. 255. In this case we would need | |
2443 | -- to use Count_Type'Base for intermediate values. | |
2444 | ||
2445 | -- Another case would be the index range -2**63 + 1 .. -2**63 + 10. The | |
2446 | -- vector would have a maximum length of 10, but the index values lie | |
2447 | -- outside the range of Count_Type (which is only 32 bits). In this | |
2448 | -- case we would need to use Index_Type'Base for intermediate values. | |
2449 | ||
2450 | if Count_Type'Base'Last >= Index_Type'Pos (Index_Type'Base'Last) then | |
2451 | return Count_Type'Base (L) - Count_Type'Base (F) + 1; | |
2452 | else | |
2453 | return Count_Type (L - F + 1); | |
2454 | end if; | |
8704d4b3 | 2455 | end Length; |
4c2d6a70 | 2456 | |
8704d4b3 MH |
2457 | ---------- |
2458 | -- Move -- | |
2459 | ---------- | |
4c2d6a70 | 2460 | |
8704d4b3 MH |
2461 | procedure Move |
2462 | (Target : in out Vector; | |
2463 | Source : in out Vector) | |
2464 | is | |
4c2d6a70 | 2465 | begin |
8704d4b3 MH |
2466 | if Target'Address = Source'Address then |
2467 | return; | |
4c2d6a70 AC |
2468 | end if; |
2469 | ||
e9f97e79 | 2470 | TC_Check (Source.TC); |
4c2d6a70 | 2471 | |
dc6b9ba2 | 2472 | Clear (Target); -- Checks busy-bit |
4c2d6a70 | 2473 | |
8704d4b3 | 2474 | declare |
d43d5ef7 | 2475 | Target_Elements : constant Elements_Access := Target.Elements; |
8704d4b3 | 2476 | begin |
d43d5ef7 MH |
2477 | Target.Elements := Source.Elements; |
2478 | Source.Elements := Target_Elements; | |
8704d4b3 | 2479 | end; |
4c2d6a70 | 2480 | |
8704d4b3 | 2481 | Target.Last := Source.Last; |
8704d4b3 MH |
2482 | Source.Last := No_Index; |
2483 | end Move; | |
2484 | ||
2485 | ---------- | |
2486 | -- Next -- | |
2487 | ---------- | |
4c2d6a70 | 2488 | |
8704d4b3 MH |
2489 | function Next (Position : Cursor) return Cursor is |
2490 | begin | |
4c2d6a70 AC |
2491 | if Position.Container = null then |
2492 | return No_Element; | |
2602b64e | 2493 | elsif Position.Index < Position.Container.Last then |
d43d5ef7 | 2494 | return (Position.Container, Position.Index + 1); |
2602b64e AC |
2495 | else |
2496 | return No_Element; | |
4c2d6a70 | 2497 | end if; |
8704d4b3 | 2498 | end Next; |
4c2d6a70 | 2499 | |
3e24afaa AC |
2500 | function Next (Object : Iterator; Position : Cursor) return Cursor is |
2501 | begin | |
e8bd500e AC |
2502 | if Position.Container = null then |
2503 | return No_Element; | |
e9f97e79 | 2504 | elsif Checks and then Position.Container /= Object.Container then |
e8bd500e AC |
2505 | raise Program_Error with |
2506 | "Position cursor of Next designates wrong vector"; | |
2602b64e AC |
2507 | else |
2508 | return Next (Position); | |
e8bd500e | 2509 | end if; |
3e24afaa AC |
2510 | end Next; |
2511 | ||
4c2d6a70 AC |
2512 | procedure Next (Position : in out Cursor) is |
2513 | begin | |
4c2d6a70 AC |
2514 | if Position.Container = null then |
2515 | return; | |
2602b64e | 2516 | elsif Position.Index < Position.Container.Last then |
d43d5ef7 | 2517 | Position.Index := Position.Index + 1; |
4c2d6a70 AC |
2518 | else |
2519 | Position := No_Element; | |
2520 | end if; | |
4c2d6a70 AC |
2521 | end Next; |
2522 | ||
8704d4b3 MH |
2523 | ------------- |
2524 | -- Prepend -- | |
2525 | ------------- | |
4c2d6a70 | 2526 | |
8704d4b3 MH |
2527 | procedure Prepend (Container : in out Vector; New_Item : Vector) is |
2528 | begin | |
2529 | Insert (Container, Index_Type'First, New_Item); | |
2530 | end Prepend; | |
2531 | ||
2532 | procedure Prepend | |
2533 | (Container : in out Vector; | |
2534 | New_Item : Element_Type; | |
2535 | Count : Count_Type := 1) | |
2536 | is | |
4c2d6a70 | 2537 | begin |
2602b64e | 2538 | Insert (Container, Index_Type'First, New_Item, Count); |
8704d4b3 | 2539 | end Prepend; |
4c2d6a70 | 2540 | |
8704d4b3 MH |
2541 | -------------- |
2542 | -- Previous -- | |
2543 | -------------- | |
2544 | ||
8704d4b3 | 2545 | function Previous (Position : Cursor) return Cursor is |
4c2d6a70 | 2546 | begin |
4c2d6a70 | 2547 | if Position.Container = null then |
8704d4b3 | 2548 | return No_Element; |
2602b64e | 2549 | elsif Position.Index > Index_Type'First then |
d43d5ef7 | 2550 | return (Position.Container, Position.Index - 1); |
2602b64e AC |
2551 | else |
2552 | return No_Element; | |
8704d4b3 | 2553 | end if; |
8704d4b3 | 2554 | end Previous; |
4c2d6a70 | 2555 | |
3e24afaa AC |
2556 | function Previous (Object : Iterator; Position : Cursor) return Cursor is |
2557 | begin | |
e8bd500e | 2558 | if Position.Container = null then |
3e24afaa | 2559 | return No_Element; |
e9f97e79 | 2560 | elsif Checks and then Position.Container /= Object.Container then |
e8bd500e AC |
2561 | raise Program_Error with |
2562 | "Position cursor of Previous designates wrong vector"; | |
2602b64e AC |
2563 | else |
2564 | return Previous (Position); | |
e8bd500e | 2565 | end if; |
3e24afaa AC |
2566 | end Previous; |
2567 | ||
e9f97e79 AC |
2568 | procedure Previous (Position : in out Cursor) is |
2569 | begin | |
2570 | if Position.Container = null then | |
2571 | return; | |
2572 | elsif Position.Index > Index_Type'First then | |
2573 | Position.Index := Position.Index - 1; | |
2574 | else | |
2575 | Position := No_Element; | |
2576 | end if; | |
2577 | end Previous; | |
2578 | ||
2579 | ---------------------- | |
2580 | -- Pseudo_Reference -- | |
2581 | ---------------------- | |
2582 | ||
2583 | function Pseudo_Reference | |
2584 | (Container : aliased Vector'Class) return Reference_Control_Type | |
2585 | is | |
2586 | TC : constant Tamper_Counts_Access := Container.TC'Unrestricted_Access; | |
2587 | begin | |
2588 | return R : constant Reference_Control_Type := (Controlled with TC) do | |
2f26abcc | 2589 | Busy (TC.all); |
e9f97e79 AC |
2590 | end return; |
2591 | end Pseudo_Reference; | |
2592 | ||
8704d4b3 MH |
2593 | ------------------- |
2594 | -- Query_Element -- | |
2595 | ------------------- | |
4c2d6a70 | 2596 | |
8704d4b3 MH |
2597 | procedure Query_Element |
2598 | (Container : Vector; | |
2599 | Index : Index_Type; | |
0ae9f22f | 2600 | Process : not null access procedure (Element : Element_Type)) |
8704d4b3 | 2601 | is |
e9f97e79 | 2602 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
8704d4b3 | 2603 | V : Vector renames Container'Unrestricted_Access.all; |
4c2d6a70 | 2604 | |
4c2d6a70 | 2605 | begin |
e9f97e79 | 2606 | if Checks and then Index > Container.Last then |
dc6b9ba2 | 2607 | raise Constraint_Error with "Index is out of range"; |
d43d5ef7 MH |
2608 | end if; |
2609 | ||
e9f97e79 | 2610 | if Checks and then V.Elements.EA (Index) = null then |
dc6b9ba2 | 2611 | raise Constraint_Error with "element is null"; |
2368f04e MH |
2612 | end if; |
2613 | ||
e9f97e79 | 2614 | Process (V.Elements.EA (Index).all); |
8704d4b3 | 2615 | end Query_Element; |
4c2d6a70 AC |
2616 | |
2617 | procedure Query_Element | |
8704d4b3 | 2618 | (Position : Cursor; |
0ae9f22f | 2619 | Process : not null access procedure (Element : Element_Type)) |
8704d4b3 | 2620 | is |
4c2d6a70 | 2621 | begin |
e9f97e79 | 2622 | if Checks and then Position.Container = null then |
dc6b9ba2 | 2623 | raise Constraint_Error with "Position cursor has no element"; |
2602b64e AC |
2624 | else |
2625 | Query_Element (Position.Container.all, Position.Index, Process); | |
d43d5ef7 | 2626 | end if; |
4c2d6a70 AC |
2627 | end Query_Element; |
2628 | ||
8704d4b3 MH |
2629 | ---------- |
2630 | -- Read -- | |
2631 | ---------- | |
4c2d6a70 | 2632 | |
8704d4b3 | 2633 | procedure Read |
dc6b9ba2 | 2634 | (Stream : not null access Root_Stream_Type'Class; |
8704d4b3 MH |
2635 | Container : out Vector) |
2636 | is | |
2637 | Length : Count_Type'Base; | |
2638 | Last : Index_Type'Base := Index_Type'Pred (Index_Type'First); | |
2602b64e | 2639 | B : Boolean; |
4c2d6a70 | 2640 | |
4c2d6a70 | 2641 | begin |
8704d4b3 | 2642 | Clear (Container); |
4c2d6a70 | 2643 | |
8704d4b3 | 2644 | Count_Type'Base'Read (Stream, Length); |
4c2d6a70 | 2645 | |
8704d4b3 MH |
2646 | if Length > Capacity (Container) then |
2647 | Reserve_Capacity (Container, Capacity => Length); | |
2648 | end if; | |
4c2d6a70 | 2649 | |
8704d4b3 | 2650 | for J in Count_Type range 1 .. Length loop |
d43d5ef7 | 2651 | Last := Last + 1; |
4c2d6a70 | 2652 | |
8704d4b3 | 2653 | Boolean'Read (Stream, B); |
4c2d6a70 | 2654 | |
8704d4b3 | 2655 | if B then |
f97ccb3a | 2656 | Container.Elements.EA (Last) := |
8704d4b3 MH |
2657 | new Element_Type'(Element_Type'Input (Stream)); |
2658 | end if; | |
2659 | ||
2660 | Container.Last := Last; | |
2661 | end loop; | |
2662 | end Read; | |
4c2d6a70 | 2663 | |
2368f04e | 2664 | procedure Read |
dc6b9ba2 | 2665 | (Stream : not null access Root_Stream_Type'Class; |
2368f04e MH |
2666 | Position : out Cursor) |
2667 | is | |
2668 | begin | |
dc6b9ba2 | 2669 | raise Program_Error with "attempt to stream vector cursor"; |
2368f04e MH |
2670 | end Read; |
2671 | ||
3e24afaa AC |
2672 | procedure Read |
2673 | (Stream : not null access Root_Stream_Type'Class; | |
2674 | Item : out Reference_Type) | |
2675 | is | |
2676 | begin | |
2677 | raise Program_Error with "attempt to stream reference"; | |
2678 | end Read; | |
2679 | ||
2680 | procedure Read | |
2681 | (Stream : not null access Root_Stream_Type'Class; | |
2682 | Item : out Constant_Reference_Type) | |
2683 | is | |
2684 | begin | |
2685 | raise Program_Error with "attempt to stream reference"; | |
2686 | end Read; | |
2687 | ||
2688 | --------------- | |
2689 | -- Reference -- | |
2690 | --------------- | |
2691 | ||
0b5b2bbc | 2692 | function Reference |
c9423ca3 | 2693 | (Container : aliased in out Vector; |
0b5b2bbc AC |
2694 | Position : Cursor) return Reference_Type |
2695 | is | |
c9423ca3 | 2696 | begin |
e9f97e79 AC |
2697 | if Checks then |
2698 | if Position.Container = null then | |
2699 | raise Constraint_Error with "Position cursor has no element"; | |
2700 | end if; | |
3e24afaa | 2701 | |
e9f97e79 AC |
2702 | if Position.Container /= Container'Unrestricted_Access then |
2703 | raise Program_Error with "Position cursor denotes wrong container"; | |
2704 | end if; | |
c9423ca3 | 2705 | |
e9f97e79 AC |
2706 | if Position.Index > Position.Container.Last then |
2707 | raise Constraint_Error with "Position cursor is out of range"; | |
2708 | end if; | |
c9423ca3 AC |
2709 | end if; |
2710 | ||
14f73211 BD |
2711 | declare |
2712 | TC : constant Tamper_Counts_Access := | |
2713 | Container.TC'Unrestricted_Access; | |
2714 | begin | |
2715 | -- The following will raise Constraint_Error if Element is null | |
2716 | ||
794b9b72 | 2717 | return R : constant Reference_Type := |
e9f97e79 | 2718 | (Element => Container.Elements.EA (Position.Index), |
14f73211 BD |
2719 | Control => (Controlled with TC)) |
2720 | do | |
2f26abcc | 2721 | Busy (TC.all); |
14f73211 BD |
2722 | end return; |
2723 | end; | |
3e24afaa AC |
2724 | end Reference; |
2725 | ||
0b5b2bbc | 2726 | function Reference |
c9423ca3 AC |
2727 | (Container : aliased in out Vector; |
2728 | Index : Index_Type) return Reference_Type | |
0b5b2bbc | 2729 | is |
3e24afaa | 2730 | begin |
e9f97e79 | 2731 | if Checks and then Index > Container.Last then |
3e24afaa AC |
2732 | raise Constraint_Error with "Index is out of range"; |
2733 | end if; | |
2734 | ||
14f73211 BD |
2735 | declare |
2736 | TC : constant Tamper_Counts_Access := | |
2737 | Container.TC'Unrestricted_Access; | |
2738 | begin | |
2739 | -- The following will raise Constraint_Error if Element is null | |
2740 | ||
794b9b72 | 2741 | return R : constant Reference_Type := |
e9f97e79 | 2742 | (Element => Container.Elements.EA (Index), |
14f73211 BD |
2743 | Control => (Controlled with TC)) |
2744 | do | |
2f26abcc | 2745 | Busy (TC.all); |
14f73211 BD |
2746 | end return; |
2747 | end; | |
3e24afaa AC |
2748 | end Reference; |
2749 | ||
8704d4b3 MH |
2750 | --------------------- |
2751 | -- Replace_Element -- | |
2752 | --------------------- | |
4c2d6a70 | 2753 | |
8704d4b3 | 2754 | procedure Replace_Element |
2368f04e | 2755 | (Container : in out Vector; |
8704d4b3 | 2756 | Index : Index_Type; |
2368f04e | 2757 | New_Item : Element_Type) |
8704d4b3 | 2758 | is |
4c2d6a70 | 2759 | begin |
e9f97e79 | 2760 | if Checks and then Index > Container.Last then |
dc6b9ba2 | 2761 | raise Constraint_Error with "Index is out of range"; |
d43d5ef7 MH |
2762 | end if; |
2763 | ||
e9f97e79 | 2764 | TE_Check (Container.TC); |
4c2d6a70 | 2765 | |
d43d5ef7 | 2766 | declare |
f97ccb3a | 2767 | X : Element_Access := Container.Elements.EA (Index); |
50878404 | 2768 | |
50878404 AC |
2769 | -- The element allocator may need an accessibility check in the case |
2770 | -- where the actual type is class-wide or has access discriminants | |
2771 | -- (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
2772 | |
2773 | pragma Unsuppress (Accessibility_Check); | |
2774 | ||
d43d5ef7 | 2775 | begin |
f97ccb3a | 2776 | Container.Elements.EA (Index) := new Element_Type'(New_Item); |
d43d5ef7 MH |
2777 | Free (X); |
2778 | end; | |
8704d4b3 | 2779 | end Replace_Element; |
4c2d6a70 | 2780 | |
2368f04e MH |
2781 | procedure Replace_Element |
2782 | (Container : in out Vector; | |
2783 | Position : Cursor; | |
2784 | New_Item : Element_Type) | |
2785 | is | |
8704d4b3 | 2786 | begin |
e9f97e79 AC |
2787 | if Checks then |
2788 | if Position.Container = null then | |
2789 | raise Constraint_Error with "Position cursor has no element"; | |
2790 | end if; | |
d43d5ef7 | 2791 | |
e9f97e79 AC |
2792 | if Position.Container /= Container'Unrestricted_Access then |
2793 | raise Program_Error with "Position cursor denotes wrong container"; | |
2794 | end if; | |
2368f04e | 2795 | |
e9f97e79 AC |
2796 | if Position.Index > Container.Last then |
2797 | raise Constraint_Error with "Position cursor is out of range"; | |
2798 | end if; | |
f97ccb3a BD |
2799 | end if; |
2800 | ||
e9f97e79 | 2801 | TE_Check (Container.TC); |
f97ccb3a BD |
2802 | |
2803 | declare | |
2804 | X : Element_Access := Container.Elements.EA (Position.Index); | |
50878404 | 2805 | |
50878404 AC |
2806 | -- The element allocator may need an accessibility check in the case |
2807 | -- where the actual type is class-wide or has access discriminants | |
2808 | -- (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
2809 | |
2810 | pragma Unsuppress (Accessibility_Check); | |
2811 | ||
f97ccb3a BD |
2812 | begin |
2813 | Container.Elements.EA (Position.Index) := new Element_Type'(New_Item); | |
2814 | Free (X); | |
2815 | end; | |
8704d4b3 | 2816 | end Replace_Element; |
4c2d6a70 | 2817 | |
8704d4b3 MH |
2818 | ---------------------- |
2819 | -- Reserve_Capacity -- | |
2820 | ---------------------- | |
4c2d6a70 | 2821 | |
8704d4b3 MH |
2822 | procedure Reserve_Capacity |
2823 | (Container : in out Vector; | |
2824 | Capacity : Count_Type) | |
2825 | is | |
2826 | N : constant Count_Type := Length (Container); | |
4c2d6a70 | 2827 | |
5bec9717 AC |
2828 | Index : Count_Type'Base; |
2829 | Last : Index_Type'Base; | |
2830 | ||
8704d4b3 | 2831 | begin |
5bec9717 AC |
2832 | -- Reserve_Capacity can be used to either expand the storage available |
2833 | -- for elements (this would be its typical use, in anticipation of | |
2834 | -- future insertion), or to trim back storage. In the latter case, | |
2835 | -- storage can only be trimmed back to the limit of the container | |
2836 | -- length. Note that Reserve_Capacity neither deletes (active) elements | |
2837 | -- nor inserts elements; it only affects container capacity, never | |
2838 | -- container length. | |
2839 | ||
8704d4b3 | 2840 | if Capacity = 0 then |
0b5b2bbc | 2841 | |
5bec9717 AC |
2842 | -- This is a request to trim back storage, to the minimum amount |
2843 | -- possible given the current state of the container. | |
2844 | ||
8704d4b3 | 2845 | if N = 0 then |
0b5b2bbc | 2846 | |
5bec9717 AC |
2847 | -- The container is empty, so in this unique case we can |
2848 | -- deallocate the entire internal array. Note that an empty | |
2849 | -- container can never be busy, so there's no need to check the | |
2850 | -- tampering bits. | |
2851 | ||
4c2d6a70 | 2852 | declare |
8704d4b3 | 2853 | X : Elements_Access := Container.Elements; |
0b5b2bbc | 2854 | |
4c2d6a70 | 2855 | begin |
5bec9717 AC |
2856 | -- First we remove the internal array from the container, to |
2857 | -- handle the case when the deallocation raises an exception | |
2858 | -- (although that's unlikely, since this is simply an array of | |
2859 | -- access values, all of which are null). | |
2860 | ||
8704d4b3 | 2861 | Container.Elements := null; |
5bec9717 AC |
2862 | |
2863 | -- Container invariants have been restored, so it is now safe | |
2864 | -- to attempt to deallocate the internal array. | |
2865 | ||
8704d4b3 | 2866 | Free (X); |
4c2d6a70 AC |
2867 | end; |
2868 | ||
f97ccb3a | 2869 | elsif N < Container.Elements.EA'Length then |
0b5b2bbc | 2870 | |
5bec9717 AC |
2871 | -- The container is not empty, and the current length is less than |
2872 | -- the current capacity, so there's storage available to trim. In | |
2873 | -- this case, we allocate a new internal array having a length | |
2874 | -- that exactly matches the number of items in the | |
2875 | -- container. (Reserve_Capacity does not delete active elements, | |
2876 | -- so this is the best we can do with respect to minimizing | |
2877 | -- storage). | |
2878 | ||
e9f97e79 | 2879 | TC_Check (Container.TC); |
8704d4b3 | 2880 | |
4c2d6a70 | 2881 | declare |
8704d4b3 MH |
2882 | subtype Array_Index_Subtype is Index_Type'Base range |
2883 | Index_Type'First .. Container.Last; | |
4c2d6a70 | 2884 | |
f97ccb3a BD |
2885 | Src : Elements_Array renames |
2886 | Container.Elements.EA (Array_Index_Subtype); | |
8704d4b3 MH |
2887 | |
2888 | X : Elements_Access := Container.Elements; | |
d43d5ef7 | 2889 | |
8704d4b3 | 2890 | begin |
5bec9717 AC |
2891 | -- Although we have isolated the old internal array that we're |
2892 | -- going to deallocate, we don't deallocate it until we have | |
2893 | -- successfully allocated a new one. If there is an exception | |
2894 | -- during allocation (because there is not enough storage), we | |
2895 | -- let it propagate without causing any side-effect. | |
2896 | ||
f97ccb3a | 2897 | Container.Elements := new Elements_Type'(Container.Last, Src); |
5bec9717 | 2898 | |
308e6f3a | 2899 | -- We have successfully allocated a new internal array (with a |
5bec9717 AC |
2900 | -- smaller length than the old one, and containing a copy of |
2901 | -- just the active elements in the container), so we can | |
2902 | -- deallocate the old array. | |
2903 | ||
8704d4b3 | 2904 | Free (X); |
4c2d6a70 | 2905 | end; |
8704d4b3 | 2906 | end if; |
4c2d6a70 | 2907 | |
8704d4b3 MH |
2908 | return; |
2909 | end if; | |
4c2d6a70 | 2910 | |
5bec9717 AC |
2911 | -- Reserve_Capacity can be used to expand the storage available for |
2912 | -- elements, but we do not let the capacity grow beyond the number of | |
2913 | -- values in Index_Type'Range. (Were it otherwise, there would be no way | |
2914 | -- to refer to the elements with index values greater than | |
2915 | -- Index_Type'Last, so that storage would be wasted.) Here we compute | |
2916 | -- the Last index value of the new internal array, in a way that avoids | |
2917 | -- any possibility of overflow. | |
2918 | ||
e9f97e79 | 2919 | if Index_Type'Base'Last >= Count_Type_Last then |
0b5b2bbc | 2920 | |
5bec9717 AC |
2921 | -- We perform a two-part test. First we determine whether the |
2922 | -- computed Last value lies in the base range of the type, and then | |
2923 | -- determine whether it lies in the range of the index (sub)type. | |
2924 | ||
2925 | -- Last must satisfy this relation: | |
2926 | -- First + Length - 1 <= Last | |
2927 | -- We regroup terms: | |
2928 | -- First - 1 <= Last - Length | |
2929 | -- Which can rewrite as: | |
2930 | -- No_Index <= Last - Length | |
2931 | ||
e9f97e79 AC |
2932 | if Checks and then |
2933 | Index_Type'Base'Last - Index_Type'Base (Capacity) < No_Index | |
2934 | then | |
5bec9717 AC |
2935 | raise Constraint_Error with "Capacity is out of range"; |
2936 | end if; | |
4c2d6a70 | 2937 | |
5bec9717 AC |
2938 | -- We now know that the computed value of Last is within the base |
2939 | -- range of the type, so it is safe to compute its value: | |
4c2d6a70 | 2940 | |
5bec9717 | 2941 | Last := No_Index + Index_Type'Base (Capacity); |
4c2d6a70 | 2942 | |
5bec9717 AC |
2943 | -- Finally we test whether the value is within the range of the |
2944 | -- generic actual index subtype: | |
2945 | ||
e9f97e79 | 2946 | if Checks and then Last > Index_Type'Last then |
5bec9717 AC |
2947 | raise Constraint_Error with "Capacity is out of range"; |
2948 | end if; | |
2949 | ||
2950 | elsif Index_Type'First <= 0 then | |
0b5b2bbc | 2951 | |
5bec9717 AC |
2952 | -- Here we can compute Last directly, in the normal way. We know that |
2953 | -- No_Index is less than 0, so there is no danger of overflow when | |
2954 | -- adding the (positive) value of Capacity. | |
2955 | ||
2956 | Index := Count_Type'Base (No_Index) + Capacity; -- Last | |
2957 | ||
e9f97e79 | 2958 | if Checks and then Index > Count_Type'Base (Index_Type'Last) then |
5bec9717 AC |
2959 | raise Constraint_Error with "Capacity is out of range"; |
2960 | end if; | |
2961 | ||
2962 | -- We know that the computed value (having type Count_Type) of Last | |
2963 | -- is within the range of the generic actual index subtype, so it is | |
2964 | -- safe to convert to Index_Type: | |
2965 | ||
2966 | Last := Index_Type'Base (Index); | |
2967 | ||
2968 | else | |
2969 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we | |
2970 | -- must test the length indirectly (by working backwards from the | |
2971 | -- largest possible value of Last), in order to prevent overflow. | |
2972 | ||
2973 | Index := Count_Type'Base (Index_Type'Last) - Capacity; -- No_Index | |
2974 | ||
e9f97e79 | 2975 | if Checks and then Index < Count_Type'Base (No_Index) then |
5bec9717 AC |
2976 | raise Constraint_Error with "Capacity is out of range"; |
2977 | end if; | |
4c2d6a70 | 2978 | |
5bec9717 AC |
2979 | -- We have determined that the value of Capacity would not create a |
2980 | -- Last index value outside of the range of Index_Type, so we can now | |
2981 | -- safely compute its value. | |
2982 | ||
2983 | Last := Index_Type'Base (Count_Type'Base (No_Index) + Capacity); | |
2984 | end if; | |
2985 | ||
2986 | -- The requested capacity is non-zero, but we don't know yet whether | |
2987 | -- this is a request for expansion or contraction of storage. | |
2988 | ||
2989 | if Container.Elements = null then | |
0b5b2bbc | 2990 | |
5bec9717 AC |
2991 | -- The container is empty (it doesn't even have an internal array), |
2992 | -- so this represents a request to allocate storage having the given | |
2993 | -- capacity. | |
2994 | ||
2995 | Container.Elements := new Elements_Type (Last); | |
4c2d6a70 AC |
2996 | return; |
2997 | end if; | |
2998 | ||
8704d4b3 | 2999 | if Capacity <= N then |
0b5b2bbc | 3000 | |
5bec9717 AC |
3001 | -- This is a request to trim back storage, but only to the limit of |
3002 | -- what's already in the container. (Reserve_Capacity never deletes | |
3003 | -- active elements, it only reclaims excess storage.) | |
3004 | ||
f97ccb3a | 3005 | if N < Container.Elements.EA'Length then |
0b5b2bbc | 3006 | |
5bec9717 AC |
3007 | -- The container is not empty (because the requested capacity is |
3008 | -- positive, and less than or equal to the container length), and | |
0b5b2bbc AC |
3009 | -- the current length is less than the current capacity, so there |
3010 | -- is storage available to trim. In this case, we allocate a new | |
3011 | -- internal array having a length that exactly matches the number | |
3012 | -- of items in the container. | |
5bec9717 | 3013 | |
e9f97e79 | 3014 | TC_Check (Container.TC); |
4c2d6a70 | 3015 | |
8704d4b3 MH |
3016 | declare |
3017 | subtype Array_Index_Subtype is Index_Type'Base range | |
3018 | Index_Type'First .. Container.Last; | |
4c2d6a70 | 3019 | |
f97ccb3a BD |
3020 | Src : Elements_Array renames |
3021 | Container.Elements.EA (Array_Index_Subtype); | |
4c2d6a70 | 3022 | |
8704d4b3 | 3023 | X : Elements_Access := Container.Elements; |
4c2d6a70 | 3024 | |
8704d4b3 | 3025 | begin |
5bec9717 AC |
3026 | -- Although we have isolated the old internal array that we're |
3027 | -- going to deallocate, we don't deallocate it until we have | |
3028 | -- successfully allocated a new one. If there is an exception | |
3029 | -- during allocation (because there is not enough storage), we | |
3030 | -- let it propagate without causing any side-effect. | |
3031 | ||
f97ccb3a | 3032 | Container.Elements := new Elements_Type'(Container.Last, Src); |
5bec9717 | 3033 | |
308e6f3a | 3034 | -- We have successfully allocated a new internal array (with a |
5bec9717 AC |
3035 | -- smaller length than the old one, and containing a copy of |
3036 | -- just the active elements in the container), so it is now | |
3037 | -- safe to deallocate the old array. | |
3038 | ||
8704d4b3 MH |
3039 | Free (X); |
3040 | end; | |
4c2d6a70 AC |
3041 | end if; |
3042 | ||
3043 | return; | |
4c2d6a70 AC |
3044 | end if; |
3045 | ||
5bec9717 AC |
3046 | -- The requested capacity is larger than the container length (the |
3047 | -- number of active elements). Whether this represents a request for | |
3048 | -- expansion or contraction of the current capacity depends on what the | |
3049 | -- current capacity is. | |
3050 | ||
f97ccb3a | 3051 | if Capacity = Container.Elements.EA'Length then |
0b5b2bbc | 3052 | |
5bec9717 AC |
3053 | -- The requested capacity matches the existing capacity, so there's |
3054 | -- nothing to do here. We treat this case as a no-op, and simply | |
3055 | -- return without checking the busy bit. | |
3056 | ||
8704d4b3 | 3057 | return; |
4c2d6a70 AC |
3058 | end if; |
3059 | ||
5bec9717 AC |
3060 | -- There is a change in the capacity of a non-empty container, so a new |
3061 | -- internal array will be allocated. (The length of the new internal | |
3062 | -- array could be less or greater than the old internal array. We know | |
3063 | -- only that the length of the new internal array is greater than the | |
3064 | -- number of active elements in the container.) We must check whether | |
3065 | -- the container is busy before doing anything else. | |
3066 | ||
e9f97e79 | 3067 | TC_Check (Container.TC); |
4c2d6a70 | 3068 | |
5bec9717 AC |
3069 | -- We now allocate a new internal array, having a length different from |
3070 | -- its current value. | |
4c2d6a70 | 3071 | |
5bec9717 AC |
3072 | declare |
3073 | X : Elements_Access := Container.Elements; | |
4c2d6a70 | 3074 | |
5bec9717 AC |
3075 | subtype Index_Subtype is Index_Type'Base range |
3076 | Index_Type'First .. Container.Last; | |
4c2d6a70 | 3077 | |
5bec9717 AC |
3078 | begin |
3079 | -- We now allocate a new internal array, having a length different | |
3080 | -- from its current value. | |
4c2d6a70 | 3081 | |
5bec9717 | 3082 | Container.Elements := new Elements_Type (Last); |
4c2d6a70 | 3083 | |
5bec9717 AC |
3084 | -- We have successfully allocated the new internal array, so now we |
3085 | -- move the existing elements from the existing the old internal | |
3086 | -- array onto the new one. Note that we're just copying access | |
3087 | -- values, to this should not raise any exceptions. | |
d43d5ef7 | 3088 | |
5bec9717 | 3089 | Container.Elements.EA (Index_Subtype) := X.EA (Index_Subtype); |
d43d5ef7 | 3090 | |
308e6f3a | 3091 | -- We have moved the elements from the old internal array, so now we |
5bec9717 | 3092 | -- can deallocate it. |
d43d5ef7 | 3093 | |
5bec9717 | 3094 | Free (X); |
8704d4b3 MH |
3095 | end; |
3096 | end Reserve_Capacity; | |
4c2d6a70 | 3097 | |
2368f04e MH |
3098 | ---------------------- |
3099 | -- Reverse_Elements -- | |
3100 | ---------------------- | |
3101 | ||
3102 | procedure Reverse_Elements (Container : in out Vector) is | |
3103 | begin | |
3104 | if Container.Length <= 1 then | |
3105 | return; | |
3106 | end if; | |
3107 | ||
b727a82b AC |
3108 | -- The exception behavior for the vector container must match that for |
3109 | -- the list container, so we check for cursor tampering here (which will | |
3110 | -- catch more things) instead of for element tampering (which will catch | |
3111 | -- fewer things). It's true that the elements of this vector container | |
3112 | -- could be safely moved around while (say) an iteration is taking place | |
794b9b72 AC |
3113 | -- (iteration only increments the busy counter), and so technically all |
3114 | -- we would need here is a test for element tampering (indicated by the | |
3115 | -- lock counter), that's simply an artifact of our array-based | |
b727a82b AC |
3116 | -- implementation. Logically Reverse_Elements requires a check for |
3117 | -- cursor tampering. | |
3118 | ||
e9f97e79 | 3119 | TC_Check (Container.TC); |
2368f04e MH |
3120 | |
3121 | declare | |
dc6b9ba2 MH |
3122 | I : Index_Type; |
3123 | J : Index_Type; | |
f97ccb3a | 3124 | E : Elements_Array renames Container.Elements.EA; |
2368f04e MH |
3125 | |
3126 | begin | |
dc6b9ba2 MH |
3127 | I := Index_Type'First; |
3128 | J := Container.Last; | |
2368f04e MH |
3129 | while I < J loop |
3130 | declare | |
3131 | EI : constant Element_Access := E (I); | |
3132 | ||
3133 | begin | |
3134 | E (I) := E (J); | |
3135 | E (J) := EI; | |
3136 | end; | |
3137 | ||
3138 | I := I + 1; | |
3139 | J := J - 1; | |
3140 | end loop; | |
3141 | end; | |
3142 | end Reverse_Elements; | |
3143 | ||
8704d4b3 MH |
3144 | ------------------ |
3145 | -- Reverse_Find -- | |
3146 | ------------------ | |
4c2d6a70 | 3147 | |
8704d4b3 MH |
3148 | function Reverse_Find |
3149 | (Container : Vector; | |
3150 | Item : Element_Type; | |
3151 | Position : Cursor := No_Element) return Cursor | |
3152 | is | |
3153 | Last : Index_Type'Base; | |
4c2d6a70 | 3154 | |
8704d4b3 | 3155 | begin |
e9f97e79 | 3156 | if Checks and then Position.Container /= null |
ef992452 | 3157 | and then Position.Container /= Container'Unrestricted_Access |
8704d4b3 | 3158 | then |
dc6b9ba2 | 3159 | raise Program_Error with "Position cursor denotes wrong container"; |
4c2d6a70 AC |
3160 | end if; |
3161 | ||
e9f97e79 AC |
3162 | Last := |
3163 | (if Position.Container = null or else Position.Index > Container.Last | |
3164 | then Container.Last | |
3165 | else Position.Index); | |
4c2d6a70 | 3166 | |
2602b64e AC |
3167 | -- Per AI05-0022, the container implementation is required to detect |
3168 | -- element tampering by a generic actual subprogram. | |
3169 | ||
3170 | declare | |
e9f97e79 | 3171 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
2602b64e | 3172 | begin |
2602b64e AC |
3173 | for Indx in reverse Index_Type'First .. Last loop |
3174 | if Container.Elements.EA (Indx) /= null | |
3175 | and then Container.Elements.EA (Indx).all = Item | |
3176 | then | |
e9f97e79 | 3177 | return Cursor'(Container'Unrestricted_Access, Indx); |
2602b64e AC |
3178 | end if; |
3179 | end loop; | |
3180 | ||
e9f97e79 | 3181 | return No_Element; |
2602b64e | 3182 | end; |
8704d4b3 | 3183 | end Reverse_Find; |
4c2d6a70 | 3184 | |
8704d4b3 MH |
3185 | ------------------------ |
3186 | -- Reverse_Find_Index -- | |
3187 | ------------------------ | |
4c2d6a70 | 3188 | |
8704d4b3 MH |
3189 | function Reverse_Find_Index |
3190 | (Container : Vector; | |
3191 | Item : Element_Type; | |
3192 | Index : Index_Type := Index_Type'Last) return Extended_Index | |
3193 | is | |
2602b64e AC |
3194 | -- Per AI05-0022, the container implementation is required to detect |
3195 | -- element tampering by a generic actual subprogram. | |
3196 | ||
e9f97e79 AC |
3197 | Lock : With_Lock (Container.TC'Unrestricted_Access); |
3198 | ||
3199 | Last : constant Index_Type'Base := | |
3200 | Index_Type'Min (Container.Last, Index); | |
2602b64e | 3201 | |
e9f97e79 | 3202 | begin |
8704d4b3 | 3203 | for Indx in reverse Index_Type'First .. Last loop |
f97ccb3a BD |
3204 | if Container.Elements.EA (Indx) /= null |
3205 | and then Container.Elements.EA (Indx).all = Item | |
8704d4b3 | 3206 | then |
e9f97e79 | 3207 | return Indx; |
8704d4b3 MH |
3208 | end if; |
3209 | end loop; | |
4c2d6a70 | 3210 | |
e9f97e79 | 3211 | return No_Index; |
8704d4b3 | 3212 | end Reverse_Find_Index; |
4c2d6a70 | 3213 | |
8704d4b3 MH |
3214 | --------------------- |
3215 | -- Reverse_Iterate -- | |
3216 | --------------------- | |
4c2d6a70 | 3217 | |
8704d4b3 MH |
3218 | procedure Reverse_Iterate |
3219 | (Container : Vector; | |
0ae9f22f | 3220 | Process : not null access procedure (Position : Cursor)) |
8704d4b3 | 3221 | is |
e9f97e79 | 3222 | Busy : With_Busy (Container.TC'Unrestricted_Access); |
8704d4b3 | 3223 | begin |
e9f97e79 AC |
3224 | for Indx in reverse Index_Type'First .. Container.Last loop |
3225 | Process (Cursor'(Container'Unrestricted_Access, Indx)); | |
3226 | end loop; | |
8704d4b3 | 3227 | end Reverse_Iterate; |
4c2d6a70 | 3228 | |
8704d4b3 MH |
3229 | ---------------- |
3230 | -- Set_Length -- | |
3231 | ---------------- | |
4c2d6a70 | 3232 | |
e9f97e79 | 3233 | procedure Set_Length (Container : in out Vector; Length : Count_Type) is |
5bec9717 | 3234 | Count : constant Count_Type'Base := Container.Length - Length; |
4c2d6a70 AC |
3235 | |
3236 | begin | |
5bec9717 AC |
3237 | -- Set_Length allows the user to set the length explicitly, instead of |
3238 | -- implicitly as a side-effect of deletion or insertion. If the | |
3239 | -- requested length is less than the current length, this is equivalent | |
3240 | -- to deleting items from the back end of the vector. If the requested | |
3241 | -- length is greater than the current length, then this is equivalent to | |
3242 | -- inserting "space" (nonce items) at the end. | |
4c2d6a70 | 3243 | |
5bec9717 AC |
3244 | if Count >= 0 then |
3245 | Container.Delete_Last (Count); | |
d43d5ef7 | 3246 | |
e9f97e79 | 3247 | elsif Checks and then Container.Last >= Index_Type'Last then |
5bec9717 | 3248 | raise Constraint_Error with "vector is already at its maximum length"; |
d43d5ef7 | 3249 | |
5bec9717 AC |
3250 | else |
3251 | Container.Insert_Space (Container.Last + 1, -Count); | |
d43d5ef7 | 3252 | end if; |
8704d4b3 | 3253 | end Set_Length; |
4c2d6a70 | 3254 | |
8704d4b3 MH |
3255 | ---------- |
3256 | -- Swap -- | |
3257 | ---------- | |
4c2d6a70 | 3258 | |
e9f97e79 | 3259 | procedure Swap (Container : in out Vector; I, J : Index_Type) is |
d43d5ef7 | 3260 | begin |
e9f97e79 AC |
3261 | if Checks then |
3262 | if I > Container.Last then | |
3263 | raise Constraint_Error with "I index is out of range"; | |
3264 | end if; | |
dc6b9ba2 | 3265 | |
e9f97e79 AC |
3266 | if J > Container.Last then |
3267 | raise Constraint_Error with "J index is out of range"; | |
3268 | end if; | |
d43d5ef7 | 3269 | end if; |
4c2d6a70 | 3270 | |
d43d5ef7 MH |
3271 | if I = J then |
3272 | return; | |
3273 | end if; | |
4c2d6a70 | 3274 | |
e9f97e79 | 3275 | TE_Check (Container.TC); |
4c2d6a70 | 3276 | |
8704d4b3 | 3277 | declare |
f97ccb3a BD |
3278 | EI : Element_Access renames Container.Elements.EA (I); |
3279 | EJ : Element_Access renames Container.Elements.EA (J); | |
d43d5ef7 MH |
3280 | |
3281 | EI_Copy : constant Element_Access := EI; | |
3282 | ||
8704d4b3 MH |
3283 | begin |
3284 | EI := EJ; | |
3285 | EJ := EI_Copy; | |
3286 | end; | |
3287 | end Swap; | |
3288 | ||
2368f04e MH |
3289 | procedure Swap |
3290 | (Container : in out Vector; | |
3291 | I, J : Cursor) | |
8704d4b3 MH |
3292 | is |
3293 | begin | |
e9f97e79 AC |
3294 | if Checks then |
3295 | if I.Container = null then | |
3296 | raise Constraint_Error with "I cursor has no element"; | |
3297 | end if; | |
4c2d6a70 | 3298 | |
e9f97e79 AC |
3299 | if J.Container = null then |
3300 | raise Constraint_Error with "J cursor has no element"; | |
3301 | end if; | |
dc6b9ba2 | 3302 | |
e9f97e79 AC |
3303 | if I.Container /= Container'Unrestricted_Access then |
3304 | raise Program_Error with "I cursor denotes wrong container"; | |
3305 | end if; | |
dc6b9ba2 | 3306 | |
e9f97e79 AC |
3307 | if J.Container /= Container'Unrestricted_Access then |
3308 | raise Program_Error with "J cursor denotes wrong container"; | |
3309 | end if; | |
4c2d6a70 AC |
3310 | end if; |
3311 | ||
2368f04e | 3312 | Swap (Container, I.Index, J.Index); |
8704d4b3 | 3313 | end Swap; |
4c2d6a70 | 3314 | |
8704d4b3 MH |
3315 | --------------- |
3316 | -- To_Cursor -- | |
3317 | --------------- | |
4c2d6a70 | 3318 | |
8704d4b3 MH |
3319 | function To_Cursor |
3320 | (Container : Vector; | |
3321 | Index : Extended_Index) return Cursor | |
3322 | is | |
4c2d6a70 | 3323 | begin |
8704d4b3 | 3324 | if Index not in Index_Type'First .. Container.Last then |
4c2d6a70 AC |
3325 | return No_Element; |
3326 | end if; | |
3327 | ||
ef992452 | 3328 | return Cursor'(Container'Unrestricted_Access, Index); |
8704d4b3 | 3329 | end To_Cursor; |
4c2d6a70 | 3330 | |
8704d4b3 MH |
3331 | -------------- |
3332 | -- To_Index -- | |
3333 | -------------- | |
4c2d6a70 | 3334 | |
8704d4b3 | 3335 | function To_Index (Position : Cursor) return Extended_Index is |
4c2d6a70 | 3336 | begin |
8704d4b3 MH |
3337 | if Position.Container = null then |
3338 | return No_Index; | |
2602b64e | 3339 | elsif Position.Index <= Position.Container.Last then |
8704d4b3 | 3340 | return Position.Index; |
2602b64e AC |
3341 | else |
3342 | return No_Index; | |
8704d4b3 | 3343 | end if; |
8704d4b3 | 3344 | end To_Index; |
4c2d6a70 | 3345 | |
8704d4b3 MH |
3346 | --------------- |
3347 | -- To_Vector -- | |
3348 | --------------- | |
4c2d6a70 | 3349 | |
8704d4b3 | 3350 | function To_Vector (Length : Count_Type) return Vector is |
5bec9717 AC |
3351 | Index : Count_Type'Base; |
3352 | Last : Index_Type'Base; | |
8255bc9d AC |
3353 | Elements : Elements_Access; |
3354 | ||
8704d4b3 MH |
3355 | begin |
3356 | if Length = 0 then | |
3357 | return Empty_Vector; | |
3358 | end if; | |
4c2d6a70 | 3359 | |
8255bc9d | 3360 | -- We create a vector object with a capacity that matches the specified |
5bec9717 | 3361 | -- Length, but we do not allow the vector capacity (the length of the |
8255bc9d AC |
3362 | -- internal array) to exceed the number of values in Index_Type'Range |
3363 | -- (otherwise, there would be no way to refer to those components via an | |
5bec9717 AC |
3364 | -- index). We must therefore check whether the specified Length would |
3365 | -- create a Last index value greater than Index_Type'Last. | |
3366 | ||
e9f97e79 | 3367 | if Index_Type'Base'Last >= Count_Type_Last then |
0b5b2bbc | 3368 | |
5bec9717 AC |
3369 | -- We perform a two-part test. First we determine whether the |
3370 | -- computed Last value lies in the base range of the type, and then | |
3371 | -- determine whether it lies in the range of the index (sub)type. | |
3372 | ||
3373 | -- Last must satisfy this relation: | |
3374 | -- First + Length - 1 <= Last | |
3375 | -- We regroup terms: | |
3376 | -- First - 1 <= Last - Length | |
3377 | -- Which can rewrite as: | |
3378 | -- No_Index <= Last - Length | |
3379 | ||
e9f97e79 AC |
3380 | if Checks and then |
3381 | Index_Type'Base'Last - Index_Type'Base (Length) < No_Index | |
3382 | then | |
dc6b9ba2 | 3383 | raise Constraint_Error with "Length is out of range"; |
d43d5ef7 MH |
3384 | end if; |
3385 | ||
5bec9717 AC |
3386 | -- We now know that the computed value of Last is within the base |
3387 | -- range of the type, so it is safe to compute its value: | |
3388 | ||
3389 | Last := No_Index + Index_Type'Base (Length); | |
3390 | ||
3391 | -- Finally we test whether the value is within the range of the | |
3392 | -- generic actual index subtype: | |
3393 | ||
e9f97e79 | 3394 | if Checks and then Last > Index_Type'Last then |
5bec9717 AC |
3395 | raise Constraint_Error with "Length is out of range"; |
3396 | end if; | |
3397 | ||
3398 | elsif Index_Type'First <= 0 then | |
0b5b2bbc | 3399 | |
5bec9717 AC |
3400 | -- Here we can compute Last directly, in the normal way. We know that |
3401 | -- No_Index is less than 0, so there is no danger of overflow when | |
3402 | -- adding the (positive) value of Length. | |
3403 | ||
3404 | Index := Count_Type'Base (No_Index) + Length; -- Last | |
3405 | ||
e9f97e79 | 3406 | if Checks and then Index > Count_Type'Base (Index_Type'Last) then |
5bec9717 AC |
3407 | raise Constraint_Error with "Length is out of range"; |
3408 | end if; | |
3409 | ||
3410 | -- We know that the computed value (having type Count_Type) of Last | |
3411 | -- is within the range of the generic actual index subtype, so it is | |
3412 | -- safe to convert to Index_Type: | |
3413 | ||
3414 | Last := Index_Type'Base (Index); | |
3415 | ||
8255bc9d | 3416 | else |
5bec9717 AC |
3417 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we |
3418 | -- must test the length indirectly (by working backwards from the | |
3419 | -- largest possible value of Last), in order to prevent overflow. | |
3420 | ||
3421 | Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index | |
3422 | ||
e9f97e79 | 3423 | if Checks and then Index < Count_Type'Base (No_Index) then |
8255bc9d AC |
3424 | raise Constraint_Error with "Length is out of range"; |
3425 | end if; | |
d43d5ef7 | 3426 | |
5bec9717 AC |
3427 | -- We have determined that the value of Length would not create a |
3428 | -- Last index value outside of the range of Index_Type, so we can now | |
3429 | -- safely compute its value. | |
3430 | ||
3431 | Last := Index_Type'Base (Count_Type'Base (No_Index) + Length); | |
8255bc9d AC |
3432 | end if; |
3433 | ||
8255bc9d AC |
3434 | Elements := new Elements_Type (Last); |
3435 | ||
e9f97e79 | 3436 | return Vector'(Controlled with Elements, Last, TC => <>); |
8704d4b3 | 3437 | end To_Vector; |
4c2d6a70 | 3438 | |
8704d4b3 MH |
3439 | function To_Vector |
3440 | (New_Item : Element_Type; | |
3441 | Length : Count_Type) return Vector | |
3442 | is | |
5bec9717 AC |
3443 | Index : Count_Type'Base; |
3444 | Last : Index_Type'Base; | |
8255bc9d AC |
3445 | Elements : Elements_Access; |
3446 | ||
8704d4b3 MH |
3447 | begin |
3448 | if Length = 0 then | |
3449 | return Empty_Vector; | |
3450 | end if; | |
4c2d6a70 | 3451 | |
8255bc9d | 3452 | -- We create a vector object with a capacity that matches the specified |
5bec9717 | 3453 | -- Length, but we do not allow the vector capacity (the length of the |
8255bc9d AC |
3454 | -- internal array) to exceed the number of values in Index_Type'Range |
3455 | -- (otherwise, there would be no way to refer to those components via an | |
5bec9717 AC |
3456 | -- index). We must therefore check whether the specified Length would |
3457 | -- create a Last index value greater than Index_Type'Last. | |
3458 | ||
e9f97e79 | 3459 | if Index_Type'Base'Last >= Count_Type_Last then |
0b5b2bbc | 3460 | |
5bec9717 AC |
3461 | -- We perform a two-part test. First we determine whether the |
3462 | -- computed Last value lies in the base range of the type, and then | |
3463 | -- determine whether it lies in the range of the index (sub)type. | |
3464 | ||
3465 | -- Last must satisfy this relation: | |
3466 | -- First + Length - 1 <= Last | |
3467 | -- We regroup terms: | |
3468 | -- First - 1 <= Last - Length | |
3469 | -- Which can rewrite as: | |
3470 | -- No_Index <= Last - Length | |
3471 | ||
e9f97e79 AC |
3472 | if Checks and then |
3473 | Index_Type'Base'Last - Index_Type'Base (Length) < No_Index | |
3474 | then | |
dc6b9ba2 | 3475 | raise Constraint_Error with "Length is out of range"; |
d43d5ef7 | 3476 | end if; |
4c2d6a70 | 3477 | |
5bec9717 AC |
3478 | -- We now know that the computed value of Last is within the base |
3479 | -- range of the type, so it is safe to compute its value: | |
3480 | ||
3481 | Last := No_Index + Index_Type'Base (Length); | |
3482 | ||
3483 | -- Finally we test whether the value is within the range of the | |
3484 | -- generic actual index subtype: | |
3485 | ||
e9f97e79 | 3486 | if Checks and then Last > Index_Type'Last then |
5bec9717 AC |
3487 | raise Constraint_Error with "Length is out of range"; |
3488 | end if; | |
3489 | ||
3490 | elsif Index_Type'First <= 0 then | |
0b5b2bbc | 3491 | |
5bec9717 AC |
3492 | -- Here we can compute Last directly, in the normal way. We know that |
3493 | -- No_Index is less than 0, so there is no danger of overflow when | |
3494 | -- adding the (positive) value of Length. | |
3495 | ||
3496 | Index := Count_Type'Base (No_Index) + Length; -- Last | |
3497 | ||
e9f97e79 | 3498 | if Checks and then Index > Count_Type'Base (Index_Type'Last) then |
5bec9717 AC |
3499 | raise Constraint_Error with "Length is out of range"; |
3500 | end if; | |
3501 | ||
3502 | -- We know that the computed value (having type Count_Type) of Last | |
3503 | -- is within the range of the generic actual index subtype, so it is | |
3504 | -- safe to convert to Index_Type: | |
3505 | ||
3506 | Last := Index_Type'Base (Index); | |
3507 | ||
8255bc9d | 3508 | else |
5bec9717 AC |
3509 | -- Here Index_Type'First (and Index_Type'Last) is positive, so we |
3510 | -- must test the length indirectly (by working backwards from the | |
3511 | -- largest possible value of Last), in order to prevent overflow. | |
3512 | ||
3513 | Index := Count_Type'Base (Index_Type'Last) - Length; -- No_Index | |
3514 | ||
e9f97e79 | 3515 | if Checks and then Index < Count_Type'Base (No_Index) then |
8255bc9d AC |
3516 | raise Constraint_Error with "Length is out of range"; |
3517 | end if; | |
4c2d6a70 | 3518 | |
5bec9717 AC |
3519 | -- We have determined that the value of Length would not create a |
3520 | -- Last index value outside of the range of Index_Type, so we can now | |
3521 | -- safely compute its value. | |
3522 | ||
3523 | Last := Index_Type'Base (Count_Type'Base (No_Index) + Length); | |
8255bc9d | 3524 | end if; |
d43d5ef7 | 3525 | |
8255bc9d | 3526 | Elements := new Elements_Type (Last); |
f97ccb3a | 3527 | |
8255bc9d AC |
3528 | -- We use Last as the index of the loop used to populate the internal |
3529 | -- array with items. In general, we prefer to initialize the loop index | |
3530 | -- immediately prior to entering the loop. However, Last is also used in | |
5bec9717 | 3531 | -- the exception handler (to reclaim elements that have been allocated, |
8255bc9d AC |
3532 | -- before propagating the exception), and the initialization of Last |
3533 | -- after entering the block containing the handler confuses some static | |
3534 | -- analysis tools, with respect to whether Last has been properly | |
3535 | -- initialized when the handler executes. So here we initialize our loop | |
3536 | -- variable earlier than we prefer, before entering the block, so there | |
3537 | -- is no ambiguity. | |
0b5b2bbc | 3538 | |
8255bc9d | 3539 | Last := Index_Type'First; |
d43d5ef7 | 3540 | |
50878404 | 3541 | declare |
50878404 AC |
3542 | -- The element allocator may need an accessibility check in the case |
3543 | -- where the actual type is class-wide or has access discriminants | |
3544 | -- (see RM 4.8(10.1) and AI12-0035). | |
29ba9f52 RD |
3545 | |
3546 | pragma Unsuppress (Accessibility_Check); | |
3547 | ||
8255bc9d AC |
3548 | begin |
3549 | loop | |
3550 | Elements.EA (Last) := new Element_Type'(New_Item); | |
3551 | exit when Last = Elements.Last; | |
3552 | Last := Last + 1; | |
3553 | end loop; | |
4c2d6a70 | 3554 | |
8255bc9d AC |
3555 | exception |
3556 | when others => | |
3557 | for J in Index_Type'First .. Last - 1 loop | |
3558 | Free (Elements.EA (J)); | |
3559 | end loop; | |
3560 | ||
3561 | Free (Elements); | |
3562 | raise; | |
8704d4b3 | 3563 | end; |
8255bc9d | 3564 | |
e9f97e79 | 3565 | return (Controlled with Elements, Last, TC => <>); |
8704d4b3 | 3566 | end To_Vector; |
4c2d6a70 | 3567 | |
8704d4b3 MH |
3568 | -------------------- |
3569 | -- Update_Element -- | |
3570 | -------------------- | |
4c2d6a70 | 3571 | |
8704d4b3 | 3572 | procedure Update_Element |
2368f04e | 3573 | (Container : in out Vector; |
8704d4b3 MH |
3574 | Index : Index_Type; |
3575 | Process : not null access procedure (Element : in out Element_Type)) | |
3576 | is | |
e9f97e79 | 3577 | Lock : With_Lock (Container.TC'Unchecked_Access); |
4c2d6a70 | 3578 | begin |
e9f97e79 | 3579 | if Checks and then Index > Container.Last then |
dc6b9ba2 | 3580 | raise Constraint_Error with "Index is out of range"; |
d43d5ef7 MH |
3581 | end if; |
3582 | ||
e9f97e79 | 3583 | if Checks and then Container.Elements.EA (Index) = null then |
dc6b9ba2 | 3584 | raise Constraint_Error with "element is null"; |
2368f04e MH |
3585 | end if; |
3586 | ||
e9f97e79 | 3587 | Process (Container.Elements.EA (Index).all); |
8704d4b3 | 3588 | end Update_Element; |
4c2d6a70 | 3589 | |
8704d4b3 | 3590 | procedure Update_Element |
2368f04e MH |
3591 | (Container : in out Vector; |
3592 | Position : Cursor; | |
3593 | Process : not null access procedure (Element : in out Element_Type)) | |
8704d4b3 MH |
3594 | is |
3595 | begin | |
e9f97e79 AC |
3596 | if Checks then |
3597 | if Position.Container = null then | |
3598 | raise Constraint_Error with "Position cursor has no element"; | |
3599 | elsif Position.Container /= Container'Unrestricted_Access then | |
3600 | raise Program_Error with "Position cursor denotes wrong container"; | |
3601 | end if; | |
2602b64e | 3602 | end if; |
e9f97e79 AC |
3603 | |
3604 | Update_Element (Container, Position.Index, Process); | |
8704d4b3 | 3605 | end Update_Element; |
4c2d6a70 | 3606 | |
8704d4b3 MH |
3607 | ----------- |
3608 | -- Write -- | |
3609 | ----------- | |
4c2d6a70 | 3610 | |
8704d4b3 | 3611 | procedure Write |
dc6b9ba2 | 3612 | (Stream : not null access Root_Stream_Type'Class; |
8704d4b3 MH |
3613 | Container : Vector) |
3614 | is | |
3615 | N : constant Count_Type := Length (Container); | |
4c2d6a70 AC |
3616 | |
3617 | begin | |
8704d4b3 | 3618 | Count_Type'Base'Write (Stream, N); |
4c2d6a70 | 3619 | |
8704d4b3 MH |
3620 | if N = 0 then |
3621 | return; | |
4c2d6a70 AC |
3622 | end if; |
3623 | ||
8704d4b3 | 3624 | declare |
f97ccb3a | 3625 | E : Elements_Array renames Container.Elements.EA; |
4c2d6a70 | 3626 | |
8704d4b3 MH |
3627 | begin |
3628 | for Indx in Index_Type'First .. Container.Last loop | |
8704d4b3 MH |
3629 | if E (Indx) = null then |
3630 | Boolean'Write (Stream, False); | |
3631 | else | |
3632 | Boolean'Write (Stream, True); | |
3633 | Element_Type'Output (Stream, E (Indx).all); | |
3634 | end if; | |
3635 | end loop; | |
3636 | end; | |
3637 | end Write; | |
4c2d6a70 | 3638 | |
2368f04e | 3639 | procedure Write |
dc6b9ba2 | 3640 | (Stream : not null access Root_Stream_Type'Class; |
2368f04e MH |
3641 | Position : Cursor) |
3642 | is | |
3643 | begin | |
dc6b9ba2 | 3644 | raise Program_Error with "attempt to stream vector cursor"; |
2368f04e MH |
3645 | end Write; |
3646 | ||
3e24afaa AC |
3647 | procedure Write |
3648 | (Stream : not null access Root_Stream_Type'Class; | |
3649 | Item : Reference_Type) | |
3650 | is | |
3651 | begin | |
3652 | raise Program_Error with "attempt to stream reference"; | |
3653 | end Write; | |
3654 | ||
3655 | procedure Write | |
3656 | (Stream : not null access Root_Stream_Type'Class; | |
3657 | Item : Constant_Reference_Type) | |
3658 | is | |
3659 | begin | |
3660 | raise Program_Error with "attempt to stream reference"; | |
3661 | end Write; | |
3662 | ||
4c2d6a70 | 3663 | end Ada.Containers.Indefinite_Vectors; |