1// This may look like C code, but it is really -*- C++ -*-
2/*
3Copyright (C) 1988 Free Software Foundation
4    written by Doug Lea (dl@rocky.oswego.edu)
5
6This file is part of GNU CC.
7
8GNU CC is distributed in the hope that it will be useful,
9but WITHOUT ANY WARRANTY.  No author or distributor
10accepts responsibility to anyone for the consequences of using it
11or for whether it serves any particular purpose or works at all,
12unless he says so in writing.  Refer to the GNU CC General Public
13License for full details.
14
15Everyone is granted permission to copy, modify and redistribute
16GNU CC, but only under the conditions described in the
17GNU CC General Public License.   A copy of this license is
18supposed to have been given to you along with GNU CC so you
19can know your rights and responsibilities.  It should be in a
20file named COPYING.  Among other things, the copyright notice
21and 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>.SLList.h"
30
31
32void <T>SLList::error(const char* msg)
33{
34  (*lib_error_handler)("SLList", msg);
35}
36
37int <T>SLList::length()
38{
39  int l = 0;
40  <T>SLListNode* t = last;
41  if (t != 0) do { ++l; t = t->tl; } while (t != last);
42  return l;
43}
44
45<T>SLList::<T>SLList(<T>SLList& a)
46{
47  if (a.last == 0)
48    last = 0;
49  else
50  {
51    <T>SLListNode* p = a.last->tl;
52    <T>SLListNode* h = new <T>SLListNode(p->hd);
53    last = h;
54    for (;;)
55    {
56      if (p == a.last)
57      {
58        last->tl = h;
59        return;
60      }
61      p = p->tl;
62      <T>SLListNode* n = new <T>SLListNode(p->hd);
63      last->tl = n;
64      last = n;
65    }
66  }
67}
68
69<T>SLList& <T>SLList::operator = (<T>SLList& a)
70{
71  if (last != a.last)
72  {
73    clear();
74    if (a.last != 0)
75    {
76      <T>SLListNode* p = a.last->tl;
77      <T>SLListNode* h = new <T>SLListNode(p->hd);
78      last = h;
79      for (;;)
80      {
81        if (p == a.last)
82        {
83          last->tl = h;
84          break;
85        }
86        p = p->tl;
87        <T>SLListNode* n = new <T>SLListNode(p->hd);
88        last->tl = n;
89        last = n;
90      }
91    }
92  }
93  return *this;
94}
95
96void <T>SLList::clear()
97{
98  if (last == 0)
99    return;
100
101  <T>SLListNode* p = last->tl;
102  last->tl = 0;
103  last = 0;
104
105  while (p != 0)
106  {
107    <T>SLListNode* nxt = p->tl;
108    delete(p);
109    p = nxt;
110  }
111}
112
113
114Pix <T>SLList::prepend(<T&> item)
115{
116  <T>SLListNode* t = new <T>SLListNode(item);
117  if (last == 0)
118    t->tl = last = t;
119  else
120  {
121    t->tl = last->tl;
122    last->tl = t;
123  }
124  return Pix(t);
125}
126
127
128Pix <T>SLList::prepend(<T>SLListNode* t)
129{
130  if (t == 0) return 0;
131  if (last == 0)
132    t->tl = last = t;
133  else
134  {
135    t->tl = last->tl;
136    last->tl = t;
137  }
138  return Pix(t);
139}
140
141
142Pix <T>SLList::append(<T&> item)
143{
144  <T>SLListNode* t = new <T>SLListNode(item);
145  if (last == 0)
146    t->tl = last = t;
147  else
148  {
149    t->tl = last->tl;
150    last->tl = t;
151    last = t;
152  }
153  return Pix(t);
154}
155
156Pix <T>SLList::append(<T>SLListNode* t)
157{
158  if (t == 0) return 0;
159  if (last == 0)
160    t->tl = last = t;
161  else
162  {
163    t->tl = last->tl;
164    last->tl = t;
165    last = t;
166  }
167  return Pix(t);
168}
169
170void <T>SLList::join(<T>SLList& b)
171{
172  <T>SLListNode* t = b.last;
173  b.last = 0;
174  if (last == 0)
175    last = t;
176  else if (t != 0)
177  {
178    <T>SLListNode* f = last->tl;
179    last->tl = t->tl;
180    t->tl = f;
181    last = t;
182  }
183}
184
185Pix <T>SLList::ins_after(Pix p, <T&> item)
186{
187  <T>SLListNode* u = (<T>SLListNode*)p;
188  <T>SLListNode* t = new <T>SLListNode(item);
189  if (last == 0)
190    t->tl = last = t;
191  else if (u == 0) // ins_after 0 means prepend
192  {
193    t->tl = last->tl;
194    last->tl = t;
195  }
196  else
197  {
198    t->tl = u->tl;
199    u->tl = t;
200    if (u == last)
201      last = t;
202  }
203  return Pix(t);
204}
205
206
207void <T>SLList::del_after(Pix p)
208{
209  <T>SLListNode* u = (<T>SLListNode*)p;
210  if (last == 0 || u == last) error("cannot del_after last");
211  if (u == 0) u = last; // del_after 0 means delete first
212  <T>SLListNode* t = u->tl;
213  if (u == t)
214    last = 0;
215  else
216  {
217    u->tl = t->tl;
218    if (last == t)
219      last = u;
220  }
221  delete t;
222}
223
224int <T>SLList::owns(Pix p)
225{
226  <T>SLListNode* t = last;
227  if (t != 0 && p != 0)
228  {
229    do
230    {
231      if (Pix(t) == p) return 1;
232      t = t->tl;
233    } while (t != last);
234  }
235  return 0;
236}
237
238<T> <T>SLList::remove_front()
239{
240  if (last == 0) error("remove_front of empty list");
241  <T>SLListNode* t = last->tl;
242  <T> res = t->hd;
243  if (t == last)
244    last = 0;
245  else
246    last->tl = t->tl;
247  delete t;
248  return res;
249}
250
251int <T>SLList::remove_front(<T>& x)
252{
253  if (last == 0)
254    return 0;
255  else
256  {
257    <T>SLListNode* t = last->tl;
258    x = t->hd;
259    if (t == last)
260      last = 0;
261    else
262      last->tl = t->tl;
263    delete t;
264    return 1;
265  }
266}
267
268
269void <T>SLList::del_front()
270{
271  if (last == 0) error("del_front of empty list");
272  <T>SLListNode* t = last->tl;
273  if (t == last)
274    last = 0;
275  else
276    last->tl = t->tl;
277  delete t;
278}
279
280int <T>SLList::OK()
281{
282  int v = 1;
283  if (last != 0)
284  {
285    <T>SLListNode* t = last;
286    long count = MAXLONG;      // Lots of chances to find last!
287    do
288    {
289      count--;
290      t = t->tl;
291    } while (count > 0 && t != last);
292    v &= count > 0;
293  }
294  if (!v) error("invariant failure");
295  return v;
296}
297