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afe17391 C |
1 | // This may look like C code, but it is really -*- C++ -*- |
2 | /* | |
3 | Copyright (C) 1988 Free Software Foundation | |
4 | written by Doug Lea (dl@rocky.oswego.edu) | |
5 | ||
6 | This file is part of GNU CC. | |
7 | ||
8 | GNU CC is distributed in the hope that it will be useful, | |
9 | but WITHOUT ANY WARRANTY. No author or distributor | |
10 | accepts responsibility to anyone for the consequences of using it | |
11 | or for whether it serves any particular purpose or works at all, | |
12 | unless he says so in writing. Refer to the GNU CC General Public | |
13 | License for full details. | |
14 | ||
15 | Everyone is granted permission to copy, modify and redistribute | |
16 | GNU CC, but only under the conditions described in the | |
17 | GNU CC General Public License. A copy of this license is | |
18 | supposed to have been given to you along with GNU CC so you | |
19 | can know your rights and responsibilities. It should be in a | |
20 | file named COPYING. Among other things, the copyright notice | |
21 | and this notice must be preserved on all copies. | |
22 | */ | |
23 | ||
24 | #ifdef __GNUG__ | |
25 | #pragma implementation | |
26 | #endif | |
27 | #include <values.h> | |
28 | #include <stream.h> | |
29 | #include "<T>.DLList.h" | |
30 | ||
31 | // error handling | |
32 | ||
33 | ||
34 | ||
35 | void <T>DLList::error(const char* msg) | |
36 | { | |
37 | (*lib_error_handler)("DLList", msg); | |
38 | } | |
39 | ||
40 | int <T>DLList::length() | |
41 | { | |
42 | int l = 0; | |
43 | <T>DLListNode* t = h; | |
44 | if (t != 0) do { ++l; t = t->fd; } while (t != h); | |
45 | return l; | |
46 | } | |
47 | ||
48 | <T>DLList::<T>DLList(<T>DLList& a) | |
49 | { | |
50 | if (a.h == 0) | |
51 | h = 0; | |
52 | else | |
53 | { | |
54 | <T>DLListNode* p = a.h; | |
55 | <T>DLListNode* t = new <T>DLListNode(p->hd); | |
56 | h = t; | |
57 | p = p->fd; | |
58 | while (p != a.h) | |
59 | { | |
60 | <T>DLListNode* n = new <T>DLListNode(p->hd); | |
61 | t->fd = n; | |
62 | n->bk = t; | |
63 | t = n; | |
64 | p = p->fd; | |
65 | } | |
66 | t->fd = h; | |
67 | h->bk = t; | |
68 | return; | |
69 | } | |
70 | } | |
71 | ||
72 | <T>DLList& <T>DLList::operator = (<T>DLList& a) | |
73 | { | |
74 | if (h != a.h) | |
75 | { | |
76 | clear(); | |
77 | if (a.h != 0) | |
78 | { | |
79 | <T>DLListNode* p = a.h; | |
80 | <T>DLListNode* t = new <T>DLListNode(p->hd); | |
81 | h = t; | |
82 | p = p->fd; | |
83 | while (p != a.h) | |
84 | { | |
85 | <T>DLListNode* n = new <T>DLListNode(p->hd); | |
86 | t->fd = n; | |
87 | n->bk = t; | |
88 | t = n; | |
89 | p = p->fd; | |
90 | } | |
91 | t->fd = h; | |
92 | h->bk = t; | |
93 | } | |
94 | } | |
95 | return *this; | |
96 | } | |
97 | ||
98 | void <T>DLList::clear() | |
99 | { | |
100 | if (h == 0) | |
101 | return; | |
102 | ||
103 | <T>DLListNode* p = h->fd; | |
104 | h->fd = 0; | |
105 | h = 0; | |
106 | ||
107 | while (p != 0) | |
108 | { | |
109 | <T>DLListNode* nxt = p->fd; | |
110 | delete(p); | |
111 | p = nxt; | |
112 | } | |
113 | } | |
114 | ||
115 | ||
116 | Pix <T>DLList::prepend(<T&> item) | |
117 | { | |
118 | <T>DLListNode* t = new <T>DLListNode(item); | |
119 | if (h == 0) | |
120 | t->fd = t->bk = h = t; | |
121 | else | |
122 | { | |
123 | t->fd = h; | |
124 | t->bk = h->bk; | |
125 | h->bk->fd = t; | |
126 | h->bk = t; | |
127 | h = t; | |
128 | } | |
129 | return Pix(t); | |
130 | } | |
131 | ||
132 | Pix <T>DLList::append(<T&> item) | |
133 | { | |
134 | <T>DLListNode* t = new <T>DLListNode(item); | |
135 | if (h == 0) | |
136 | t->fd = t->bk = h = t; | |
137 | else | |
138 | { | |
139 | t->bk = h->bk; | |
140 | t->bk->fd = t; | |
141 | t->fd = h; | |
142 | h->bk = t; | |
143 | } | |
144 | return Pix(t); | |
145 | } | |
146 | ||
147 | Pix <T>DLList::ins_after(Pix p, <T&> item) | |
148 | { | |
149 | if (p == 0) return prepend(item); | |
150 | <T>DLListNode* u = (<T>DLListNode*) p; | |
151 | <T>DLListNode* t = new <T>DLListNode(item, u, u->fd); | |
152 | u->fd->bk = t; | |
153 | u->fd = t; | |
154 | return Pix(t); | |
155 | } | |
156 | ||
157 | Pix <T>DLList::ins_before(Pix p, <T&> item) | |
158 | { | |
159 | if (p == 0) error("null Pix"); | |
160 | <T>DLListNode* u = (<T>DLListNode*) p; | |
161 | <T>DLListNode* t = new <T>DLListNode(item, u->bk, u); | |
162 | u->bk->fd = t; | |
163 | u->bk = t; | |
164 | if (u == h) h = t; | |
165 | return Pix(t); | |
166 | } | |
167 | ||
168 | void <T>DLList::join(<T>DLList& b) | |
169 | { | |
170 | <T>DLListNode* t = b.h; | |
171 | b.h = 0; | |
172 | if (h == 0) | |
173 | h = t; | |
174 | else if (t != 0) | |
175 | { | |
176 | <T>DLListNode* l = t->bk; | |
177 | h->bk->fd = t; | |
178 | t->bk = h->bk; | |
179 | h->bk = l; | |
180 | l->fd = h; | |
181 | } | |
182 | } | |
183 | ||
184 | int <T>DLList::owns(Pix p) | |
185 | { | |
186 | <T>DLListNode* t = h; | |
187 | if (t != 0 && p != 0) | |
188 | { | |
189 | do | |
190 | { | |
191 | if (Pix(t) == p) return 1; | |
192 | t = t->fd; | |
193 | } while (t != h); | |
194 | } | |
195 | return 0; | |
196 | } | |
197 | ||
198 | void <T>DLList::del(Pix& p, int dir) | |
199 | { | |
200 | if (p == 0) error("null Pix"); | |
201 | <T>DLListNode* t = (<T>DLListNode*) p; | |
202 | if (t->fd == t) | |
203 | { | |
204 | h = 0; | |
205 | p = 0; | |
206 | } | |
207 | else | |
208 | { | |
209 | if (dir < 0) | |
210 | { | |
211 | if (t == h) | |
212 | p = 0; | |
213 | else | |
214 | p = Pix(t->bk); | |
215 | } | |
216 | else | |
217 | { | |
218 | if (t == h->bk) | |
219 | p = 0; | |
220 | else | |
221 | p = Pix(t->fd); | |
222 | } | |
223 | t->bk->fd = t->fd; | |
224 | t->fd->bk = t->bk; | |
225 | if (t == h) h = t->fd; | |
226 | } | |
227 | delete t; | |
228 | } | |
229 | ||
230 | <T> <T>DLList::remove_front() | |
231 | { | |
232 | if (h == 0) | |
233 | error("remove_front of empty list"); | |
234 | <T>DLListNode* t = h; | |
235 | <T> res = t->hd; | |
236 | if (h->fd == h) | |
237 | h = 0; | |
238 | else | |
239 | { | |
240 | h->fd->bk = h->bk; | |
241 | h->bk->fd = h->fd; | |
242 | h = h->fd; | |
243 | } | |
244 | delete t; | |
245 | return res; | |
246 | } | |
247 | ||
248 | ||
249 | void <T>DLList::del_front() | |
250 | { | |
251 | if (h == 0) | |
252 | error("del_front of empty list"); | |
253 | <T>DLListNode* t = h; | |
254 | if (h->fd == h) | |
255 | h = 0; | |
256 | else | |
257 | { | |
258 | h->fd->bk = h->bk; | |
259 | h->bk->fd = h->fd; | |
260 | h = h->fd; | |
261 | } | |
262 | delete t; | |
263 | } | |
264 | ||
265 | <T> <T>DLList::remove_rear() | |
266 | { | |
267 | if (h == 0) | |
268 | error("remove_rear of empty list"); | |
269 | <T>DLListNode* t = h->bk; | |
270 | <T> res = t->hd; | |
271 | if (h->fd == h) | |
272 | h = 0; | |
273 | else | |
274 | { | |
275 | t->fd->bk = t->bk; | |
276 | t->bk->fd = t->fd; | |
277 | } | |
278 | delete t; | |
279 | return res; | |
280 | } | |
281 | ||
282 | ||
283 | void <T>DLList::del_rear() | |
284 | { | |
285 | if (h == 0) | |
286 | error("del_rear of empty list"); | |
287 | <T>DLListNode* t = h->bk; | |
288 | if (h->fd == h) | |
289 | h = 0; | |
290 | else | |
291 | { | |
292 | t->fd->bk = t->bk; | |
293 | t->bk->fd = t->fd; | |
294 | } | |
295 | delete t; | |
296 | } | |
297 | ||
298 | ||
299 | int <T>DLList::OK() | |
300 | { | |
301 | int v = 1; | |
302 | if (h != 0) | |
303 | { | |
304 | <T>DLListNode* t = h; | |
305 | long count = MAXLONG; // Lots of chances to find h! | |
306 | do | |
307 | { | |
308 | count--; | |
309 | v &= t->bk->fd == t; | |
310 | v &= t->fd->bk == t; | |
311 | t = t->fd; | |
312 | } while (v && count > 0 && t != h); | |
313 | v &= count > 0; | |
314 | } | |
315 | if (!v) error("invariant failure"); | |
316 | return v; | |
317 | } |