1 | #pragma once |
---|
2 | |
---|
3 | #include "bits/collection.hfa" |
---|
4 | #include "bits/defs.hfa" |
---|
5 | |
---|
6 | struct Seqable { |
---|
7 | __cfa_anonymous_object(Colable); |
---|
8 | struct Seqable * back; // pointer to previous node in the list |
---|
9 | }; |
---|
10 | |
---|
11 | #ifdef __cforall |
---|
12 | static inline { |
---|
13 | // PUBLIC |
---|
14 | |
---|
15 | void ?{}( Seqable & sq ) with( sq ) { |
---|
16 | ((Colable &)sq){}; |
---|
17 | back = 0p; |
---|
18 | } // post: ! listed() |
---|
19 | |
---|
20 | Seqable & getBack( Seqable & sq ) with( sq ) { |
---|
21 | return *back; |
---|
22 | } |
---|
23 | |
---|
24 | // PRIVATE |
---|
25 | |
---|
26 | Seqable *& Back( Seqable * sq ) { |
---|
27 | return sq->back; |
---|
28 | } |
---|
29 | |
---|
30 | // // wrappers to make Collection have T |
---|
31 | // forall( dtype T ) { |
---|
32 | // T *& Back( T * n ) { |
---|
33 | // return (T *)Back( (Seqable *)n ); |
---|
34 | // } |
---|
35 | // } // distribution |
---|
36 | } // distribution |
---|
37 | |
---|
38 | forall( dtype T | { T *& Back ( T * ); T *& Next ( T * ); bool listed ( T * ); } ) { |
---|
39 | struct Sequence { |
---|
40 | inline Collection; // Plan 9 inheritance |
---|
41 | }; |
---|
42 | |
---|
43 | static inline { |
---|
44 | // wrappers to make Collection have T |
---|
45 | T & head( Sequence(T) & s ) with( s ) { |
---|
46 | return *(T *)head( (Collection &)s ); |
---|
47 | } // post: empty() & head() == 0 | !empty() & head() in *s |
---|
48 | |
---|
49 | void ?{}( Sequence(T) &, const Sequence(T) & ) = void; // no copy |
---|
50 | Sequence(T) & ?=?( const Sequence(T) & ) = void; // no assignment |
---|
51 | |
---|
52 | void ?{}( Sequence(T) & s ) with( s ) { |
---|
53 | ((Collection &)s){}; |
---|
54 | } // post: isEmpty(). |
---|
55 | |
---|
56 | // Return a pointer to the last sequence element, without removing it. |
---|
57 | T & tail( Sequence(T) & s ) with( s ) { |
---|
58 | return root ? (T &)*Back( &head( s ) ) : *0p; |
---|
59 | } // post: empty() & tail() == 0 | !empty() & tail() in *s |
---|
60 | |
---|
61 | // Return a pointer to the element after *n, or 0p if list empty. |
---|
62 | T * succ( Sequence(T) & s, T * n ) with( s ) { // pre: *n in *s |
---|
63 | #ifdef __CFA_DEBUG__ |
---|
64 | if ( ! listed( n ) ) abort( "(Sequence &)%p.succ( %p ) : Node is not on a list.", &s, n ); |
---|
65 | #endif // __CFA_DEBUG__ |
---|
66 | return Next( n ) == &head( s ) ? 0p : Next( n ); |
---|
67 | } // post: n == tail() & succ(n) == 0 | n != tail() & *succ(n) in *s |
---|
68 | |
---|
69 | // Return a pointer to the element before *n, or 0p if there isn't one. |
---|
70 | T * pred( Sequence(T) & s, T * n ) with( s ) { // pre: *n in *s |
---|
71 | #ifdef __CFA_DEBUG__ |
---|
72 | if ( ! listed( n ) ) abort( "(Sequence &)%p.pred( %p ) : Node is not on a list.", &s, n ); |
---|
73 | #endif // __CFA_DEBUG__ |
---|
74 | return n == &head( s ) ? 0p : Back( n ); |
---|
75 | } // post: n == head() & head(n) == 0 | n != head() & *pred(n) in *s |
---|
76 | |
---|
77 | |
---|
78 | // Insert *n into the sequence before *bef, or at the end if bef == 0. |
---|
79 | void insertBef( Sequence(T) & s, T & n, T & bef ) with( s ) { // pre: !n->listed() & *bef in *s |
---|
80 | #ifdef __CFA_DEBUG__ |
---|
81 | if ( listed( &n ) ) abort( "(Sequence &)%p.insertBef( %p, %p ) : Node is already on another list.", &s, n, &bef ); |
---|
82 | #endif // __CFA_DEBUG__ |
---|
83 | if ( &bef == &head( s ) ) { // must change root |
---|
84 | if ( root ) { |
---|
85 | Next( &n ) = &head( s ); |
---|
86 | Back( &n ) = Back( &head( s ) ); |
---|
87 | // inserted node must be consistent before it is seen |
---|
88 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
89 | Back( &head( s ) ) = &n; |
---|
90 | Next( Back( &n ) ) = &n; |
---|
91 | } else { |
---|
92 | Next( &n ) = &n; |
---|
93 | Back( &n ) = &n; |
---|
94 | } // if |
---|
95 | // inserted node must be consistent before it is seen |
---|
96 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
97 | root = &n; |
---|
98 | } else { |
---|
99 | if ( ! &bef ) &bef = &head( s ); |
---|
100 | Next( &n ) = &bef; |
---|
101 | Back( &n ) = Back( &bef ); |
---|
102 | // inserted node must be consistent before it is seen |
---|
103 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
104 | Back( &bef ) = &n; |
---|
105 | Next( Back( &n ) ) = &n; |
---|
106 | } // if |
---|
107 | } // post: n->listed() & *n in *s & succ(n) == bef |
---|
108 | |
---|
109 | |
---|
110 | // Insert *n into the sequence after *aft, or at the beginning if aft == 0. |
---|
111 | void insertAft( Sequence(T) & s, T & aft, T & n ) with( s ) { // pre: !n->listed() & *aft in *s |
---|
112 | #ifdef __CFA_DEBUG__ |
---|
113 | if ( listed( &n ) ) abort( "(Sequence &)%p.insertAft( %p, %p ) : Node is already on another list.", &s, &aft, &n ); |
---|
114 | #endif // __CFA_DEBUG__ |
---|
115 | if ( ! &aft ) { // must change root |
---|
116 | if ( root ) { |
---|
117 | Next( &n ) = &head( s ); |
---|
118 | Back( &n ) = Back( &head( s ) ); |
---|
119 | // inserted node must be consistent before it is seen |
---|
120 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
121 | Back( &head( s ) ) = &n; |
---|
122 | Next( Back( &n ) ) = &n; |
---|
123 | } else { |
---|
124 | Next( &n ) = &n; |
---|
125 | Back( &n ) = &n; |
---|
126 | } // if |
---|
127 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
128 | root = &n; |
---|
129 | } else { |
---|
130 | Next( &n ) = Next( &aft ); |
---|
131 | Back( &n ) = &aft; |
---|
132 | // inserted node must be consistent before it is seen |
---|
133 | asm( "" : : : "memory" ); // prevent code movement across barrier |
---|
134 | Back( Next( &n ) ) = &n; |
---|
135 | Next( &aft ) = &n; |
---|
136 | } // if |
---|
137 | } // post: n->listed() & *n in *s & succ(n) == bef |
---|
138 | |
---|
139 | // pre: n->listed() & *n in *s |
---|
140 | void remove( Sequence(T) & s, T & n ) with( s ) { // O(1) |
---|
141 | #ifdef __CFA_DEBUG__ |
---|
142 | if ( ! listed( &n ) ) abort( "(Sequence &)%p.remove( %p ) : Node is not on a list.", &s, &n ); |
---|
143 | #endif // __CFA_DEBUG__ |
---|
144 | if ( &n == &head( s ) ) { |
---|
145 | if ( Next( &head( s ) ) == &head( s ) ) root = 0p; |
---|
146 | else root = Next( &head( s ) ); |
---|
147 | } // if |
---|
148 | Back( Next( &n ) ) = Back( &n ); |
---|
149 | Next( Back( &n ) ) = Next( &n ); |
---|
150 | Next( &n ) = Back( &n ) = 0p; |
---|
151 | } // post: !n->listed(). |
---|
152 | |
---|
153 | // Add an element to the head of the sequence. |
---|
154 | void addHead( Sequence(T) & s, T & n ) { // pre: !n->listed(); post: n->listed() & head() == n |
---|
155 | insertAft( s, *0p, n ); |
---|
156 | } |
---|
157 | // Add an element to the tail of the sequence. |
---|
158 | void addTail( Sequence(T) & s, T & n ) { // pre: !n->listed(); post: n->listed() & head() == n |
---|
159 | insertBef( s, n, *0p ); |
---|
160 | } |
---|
161 | // Add an element to the tail of the sequence. |
---|
162 | void add( Sequence(T) & s, T & n ) { // pre: !n->listed(); post: n->listed() & head() == n |
---|
163 | addTail( s, n ); |
---|
164 | } |
---|
165 | // Remove and return the head element in the sequence. |
---|
166 | T & dropHead( Sequence(T) & s ) { |
---|
167 | T & n = head( s ); |
---|
168 | return &n ? remove( s, n ), n : *0p; |
---|
169 | } |
---|
170 | // Remove and return the head element in the sequence. |
---|
171 | T & drop( Sequence(T) & s ) { |
---|
172 | return dropHead( s ); |
---|
173 | } |
---|
174 | // Remove and return the tail element in the sequence. |
---|
175 | T & dropTail( Sequence(T) & s ) { |
---|
176 | T & n = tail( s ); |
---|
177 | return &n ? remove( s, n ), n : *0p; |
---|
178 | } |
---|
179 | |
---|
180 | // Transfer the "from" list to the end of s sequence; the "from" list is empty after the transfer. |
---|
181 | void transfer( Sequence(T) & s, Sequence(T) & from ) with( s ) { |
---|
182 | if ( empty( from ) ) return; // "from" list empty ? |
---|
183 | if ( empty( s ) ) { // "to" list empty ? |
---|
184 | root = from.root; |
---|
185 | } else { // "to" list not empty |
---|
186 | T * toEnd = Back( &head( s ) ); |
---|
187 | T * fromEnd = Back( &head( from ) ); |
---|
188 | Back( (T *)root ) = fromEnd; |
---|
189 | Next( fromEnd ) = &head( s ); |
---|
190 | Back( (T *)from.root ) = toEnd; |
---|
191 | Next( toEnd ) = &head( from ); |
---|
192 | } // if |
---|
193 | from.root = 0p; // mark "from" list empty |
---|
194 | } |
---|
195 | |
---|
196 | // Transfer the "from" list up to node "n" to the end of s list; the "from" list becomes the sequence after node "n". |
---|
197 | // Node "n" must be in the "from" list. |
---|
198 | void split( Sequence(T) & s, Sequence(T) & from, T & n ) with( s ) { |
---|
199 | #ifdef __CFA_DEBUG__ |
---|
200 | if ( ! listed( &n ) ) abort( "(Sequence &)%p.split( %p ) : Node is not on a list.", &s, &n ); |
---|
201 | #endif // __CFA_DEBUG__ |
---|
202 | Sequence(T) to; |
---|
203 | to.root = from.root; // start of "to" list |
---|
204 | from.root = Next( &n ); // start of "from" list |
---|
205 | if ( to.root == from.root ) { // last node in list ? |
---|
206 | from.root = 0p; // mark "from" list empty |
---|
207 | } else { |
---|
208 | Back( &head( from ) ) = Back( &head( to ) ); // fix "from" list |
---|
209 | Next( Back( &head( to ) ) ) = &head( from ); |
---|
210 | Next( &n ) = &head( to ); // fix "to" list |
---|
211 | Back( &head( to ) ) = &n; |
---|
212 | } // if |
---|
213 | transfer( s, to ); |
---|
214 | } |
---|
215 | } // distribution |
---|
216 | } // distribution |
---|
217 | |
---|
218 | forall( dtype T | { T *& Back ( T * ); T *& Next ( T * ); bool listed ( T * ); } ) { |
---|
219 | // SeqIter(T) is used to iterate over a Sequence(T) in head-to-tail order. |
---|
220 | struct SeqIter { |
---|
221 | inline ColIter; |
---|
222 | // The Sequence must be passed to pred and succ to check for the end of the Sequence and return 0p. Without |
---|
223 | // passing the sequence, traversing would require its length. Thus the iterator needs a pointer to the sequence |
---|
224 | // to pass to succ/pred. Both stack and queue just encounter 0p since the lists are not circular. |
---|
225 | Sequence(T) * seq; // FIX ME: cannot be reference |
---|
226 | }; |
---|
227 | |
---|
228 | static inline { |
---|
229 | void ?{}( SeqIter(T) & si ) with( si ) { |
---|
230 | ((ColIter &)si){}; |
---|
231 | seq = 0p; |
---|
232 | } // post: elts = null. |
---|
233 | |
---|
234 | void ?{}( SeqIter(T) & si, Sequence(T) & s ) with( si ) { |
---|
235 | ((ColIter &)si){}; |
---|
236 | seq = &s; |
---|
237 | curr = &head( s ); |
---|
238 | } // post: elts = null. |
---|
239 | |
---|
240 | void ?{}( SeqIter(T) & si, Sequence(T) & s, T & start ) with( si ) { |
---|
241 | ((ColIter &)si){}; |
---|
242 | seq = &s; |
---|
243 | curr = &start; |
---|
244 | } // post: elts = null. |
---|
245 | |
---|
246 | void over( SeqIter(T) & si, Sequence(T) & s ) with( si ) { |
---|
247 | seq = &s; |
---|
248 | curr = &head( s ); |
---|
249 | } // post: elts = {e in s}. |
---|
250 | |
---|
251 | bool ?>>?( SeqIter(T) & si, T && tp ) with( si ) { |
---|
252 | if ( curr ) { |
---|
253 | &tp = Curr( si ); |
---|
254 | T * n = succ( *seq, Curr( si ) ); |
---|
255 | curr = n == &head( *seq ) ? 0p : n; |
---|
256 | } else &tp = 0p; |
---|
257 | return &tp != 0p; |
---|
258 | } |
---|
259 | } // distribution |
---|
260 | |
---|
261 | |
---|
262 | // A SeqIterRev(T) is used to iterate over a Sequence(T) in tail-to-head order. |
---|
263 | struct SeqIterRev { |
---|
264 | inline ColIter; |
---|
265 | // See above for explanation. |
---|
266 | Sequence(T) * seq; // FIX ME: cannot be reference |
---|
267 | }; |
---|
268 | |
---|
269 | static inline { |
---|
270 | void ?{}( SeqIterRev(T) & si ) with( si ) { |
---|
271 | ((ColIter &)si){}; |
---|
272 | seq = 0p; |
---|
273 | } // post: elts = null. |
---|
274 | |
---|
275 | void ?{}( SeqIterRev(T) & si, Sequence(T) & s ) with( si ) { |
---|
276 | ((ColIter &)si){}; |
---|
277 | seq = &s; |
---|
278 | curr = &tail( s ); |
---|
279 | } // post: elts = null. |
---|
280 | |
---|
281 | void ?{}( SeqIterRev(T) & si, Sequence(T) & s, T & start ) with( si ) { |
---|
282 | ((ColIter &)si){}; |
---|
283 | seq = &s; |
---|
284 | curr = &start; |
---|
285 | } // post: elts = null. |
---|
286 | |
---|
287 | void over( SeqIterRev(T) & si, Sequence(T) & s ) with( si ) { |
---|
288 | seq = &s; |
---|
289 | curr = &tail( s ); |
---|
290 | } // post: elts = {e in s}. |
---|
291 | |
---|
292 | bool ?>>?( SeqIterRev(T) & si, T && tp ) with( si ) { |
---|
293 | if ( curr ) { |
---|
294 | &tp = Curr( si ); |
---|
295 | T * n = pred( *seq, Curr( si ) ); |
---|
296 | curr = n == &tail( *seq ) ? 0p : n; |
---|
297 | } else &tp = 0p; |
---|
298 | return &tp != 0p; |
---|
299 | } |
---|
300 | } // distribution |
---|
301 | } // distribution |
---|
302 | |
---|
303 | #endif |
---|