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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Christian Schulte <schulte@gecode.org>
5 *
6 * Copyright:
7 * Christian Schulte, 2004
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34#include <sstream>
35
36namespace Gecode {
37
38 /**
39 * \brief Data stored for a %DFA
40 *
41 */
42 class DFA::DFAI : public SharedHandle::Object {
43 public:
44 /// Number of states
45 int n_states;
46 /// Number of symbols
47 unsigned int n_symbols;
48 /// Number of transitions
49 int n_trans;
50 /// Maximal degree (in-degree and out-degree of any state) and maximal number of transitions per symbol
51 unsigned int max_degree;
52 /// First final state
53 int final_fst;
54 /// Last final state
55 int final_lst;
56 /// Hash key
57 std::size_t key;
58 /// The transitions
59 Transition* trans;
60 /// Specification of transition range
61 class HashEntry {
62 public:
63 int symbol; ///< Symbol
64 const Transition* fst; ///< First transition for the symbol
65 const Transition* lst; ///< Last transition for the symbol
66 };
67 /// The transition hash table by symbol
68 HashEntry* table;
69 /// Size of table (as binary logarithm)
70 int n_log;
71 /// Fill hash table
72 void fill(void);
73 /// Initialize automaton implementation with \a nt transitions
74 DFAI(int nt);
75 /// Initialize automaton implementation as empty
76 GECODE_INT_EXPORT DFAI(void);
77 /// Delete automaton implemenentation
78 virtual ~DFAI(void);
79 };
80
81 forceinline
82 DFA::DFAI::DFAI(int nt)
83 : trans(nt == 0 ? nullptr : heap.alloc<Transition>(nt)) {}
84
85 forceinline
86 DFA::DFAI::~DFAI(void) {
87 if (n_trans > 0)
88 heap.rfree(trans);
89 heap.rfree(table);
90 }
91
92 forceinline void
93 DFA::DFAI::fill(void) {
94 key = static_cast<std::size_t>(n_states);
95 cmb_hash(key, n_trans);
96 cmb_hash(key, n_symbols);
97 cmb_hash(key, final_fst);
98 cmb_hash(key, final_lst);
99 // Compute smallest logarithm larger than n_symbols
100 n_log = 1;
101 while (n_symbols >= static_cast<unsigned int>(1<<n_log))
102 n_log++;
103 // Allocate memory
104 table = heap.alloc<HashEntry>(1<<n_log);
105 // Initialize table
106 for (int i=(1<<n_log); i--; )
107 table[i].fst = table[i].lst = nullptr;
108 int mask = (1 << n_log) - 1;
109 // Enter transitions to table
110 for (int i = 0; i<n_trans; ) {
111 cmb_hash(key, trans[i].i_state);
112 cmb_hash(key, trans[i].symbol);
113 cmb_hash(key, trans[i].o_state);
114 int s = trans[i].symbol;
115 Transition* fst = &trans[i];
116 i++;
117 while ((i<n_trans) && (trans[i].symbol == s))
118 i++;
119 Transition* lst = &trans[i];
120 // Enter with linear collision resolution
121 int p = s & mask;
122 while (table[p].fst != nullptr)
123 p = (p+1) & mask;
124 table[p].symbol = s;
125 table[p].fst = fst;
126 table[p].lst = lst;
127 }
128 }
129
130 forceinline
131 DFA::DFA(void) {}
132
133
134 forceinline
135 DFA::DFA(const DFA& d)
136 : SharedHandle(d) {}
137
138 forceinline int
139 DFA::n_states(void) const {
140 const DFAI* d = static_cast<DFAI*>(object());
141 return (d == nullptr) ? 1 : d->n_states;
142 }
143
144 forceinline unsigned int
145 DFA::n_symbols(void) const {
146 const DFAI* d = static_cast<DFAI*>(object());
147 return (d == nullptr) ? 0 : d->n_symbols;
148 }
149
150 forceinline int
151 DFA::n_transitions(void) const {
152 const DFAI* d = static_cast<DFAI*>(object());
153 return (d == nullptr) ? 0 : d->n_trans;
154 }
155
156 forceinline unsigned int
157 DFA::max_degree(void) const {
158 const DFAI* d = static_cast<DFAI*>(object());
159 return (d == nullptr) ? 0 : d->max_degree;
160 }
161
162 forceinline int
163 DFA::final_fst(void) const {
164 const DFAI* d = static_cast<DFAI*>(object());
165 return (d == nullptr) ? 0 : d->final_fst;
166 }
167
168 forceinline int
169 DFA::final_lst(void) const {
170 const DFAI* d = static_cast<DFAI*>(object());
171 return (d == nullptr) ? 0 : d->final_lst;
172 }
173
174 forceinline int
175 DFA::symbol_min(void) const {
176 const DFAI* d = static_cast<DFAI*>(object());
177 return ((d != nullptr) && (d->n_trans > 0)) ?
178 d->trans[0].symbol : Int::Limits::min;
179 }
180
181 forceinline int
182 DFA::symbol_max(void) const {
183 const DFAI* d = static_cast<DFAI*>(object());
184 return ((d != nullptr) && (d->n_trans > 0)) ?
185 d->trans[d->n_trans-1].symbol : Int::Limits::max;
186 }
187
188 forceinline std::size_t
189 DFA::hash(void) const {
190 const DFAI* d = static_cast<DFAI*>(object());
191 return (d != nullptr) ? d->key : 0;
192 }
193
194
195 /*
196 * Constructing transitions
197 *
198 */
199
200 forceinline
201 DFA::Transition::Transition(void) {}
202
203 forceinline
204 DFA::Transition::Transition(int i_state0, int symbol0, int o_state0)
205 : i_state(i_state0), symbol(symbol0), o_state(o_state0) {}
206
207 /*
208 * Iterating over all transitions
209 *
210 */
211
212 forceinline
213 DFA::Transitions::Transitions(const DFA& d) {
214 const DFAI* o = static_cast<DFAI*>(d.object());
215 if (o != nullptr) {
216 c_trans = &o->trans[0];
217 e_trans = c_trans+o->n_trans;
218 } else {
219 c_trans = e_trans = nullptr;
220 }
221 }
222
223 forceinline
224 DFA::Transitions::Transitions(const DFA& d, int n) {
225 const DFAI* o = static_cast<DFAI*>(d.object());
226 if (o != nullptr) {
227 int mask = (1<<o->n_log)-1;
228 int p = n & mask;
229 while ((o->table[p].fst != nullptr) && (o->table[p].symbol != n))
230 p = (p+1) & mask;
231 c_trans = o->table[p].fst;
232 e_trans = o->table[p].lst;
233 } else {
234 c_trans = e_trans = nullptr;
235 }
236 }
237
238 forceinline bool
239 DFA::Transitions::operator ()(void) const {
240 return c_trans < e_trans;
241 }
242
243 forceinline void
244 DFA::Transitions::operator ++(void) {
245 c_trans++;
246 }
247
248 forceinline int
249 DFA::Transitions::i_state(void) const {
250 return c_trans->i_state;
251 }
252
253 forceinline int
254 DFA::Transitions::symbol(void) const {
255 return c_trans->symbol;
256 }
257
258 forceinline int
259 DFA::Transitions::o_state(void) const {
260 return c_trans->o_state;
261 }
262
263 /*
264 * Iterating over symbols
265 *
266 */
267
268 forceinline
269 DFA::Symbols::Symbols(const DFA& d) {
270 const DFAI* o = static_cast<DFAI*>(d.object());
271 if (o != nullptr) {
272 c_trans = &o->trans[0];
273 e_trans = c_trans+o->n_trans;
274 } else {
275 c_trans = e_trans = nullptr;
276 }
277 }
278
279 forceinline bool
280 DFA::Symbols::operator ()(void) const {
281 return c_trans < e_trans;
282 }
283
284 forceinline void
285 DFA::Symbols::operator ++(void) {
286 int s = c_trans->symbol;
287 do {
288 c_trans++;
289 } while ((c_trans < e_trans) && (s == c_trans->symbol));
290 }
291
292 forceinline int
293 DFA::Symbols::val(void) const {
294 return c_trans->symbol;
295 }
296
297
298 template<class Char, class Traits>
299 std::basic_ostream<Char,Traits>&
300 operator <<(std::basic_ostream<Char,Traits>& os, const DFA& d) {
301 std::basic_ostringstream<Char,Traits> st;
302 st.copyfmt(os); st.width(0);
303 st << "Start state: 0" << std::endl
304 << "States: 0..." << d.n_states()-1 << std::endl
305 << "Transitions:";
306 for (int s = 0; s < static_cast<int>(d.n_states()); s++) {
307 DFA::Transitions t(d);
308 int n = 0;
309 while (t()) {
310 if (t.i_state() == s) {
311 if ((n % 4) == 0)
312 st << std::endl << "\t";
313 st << "[" << t.i_state() << "]"
314 << "- " << t.symbol() << " >"
315 << "[" << t.o_state() << "] ";
316 ++n;
317 }
318 ++t;
319 }
320 }
321 st << std::endl << "Final states: "
322 << std::endl
323 << "\t[" << d.final_fst() << "] ... ["
324 << d.final_lst()-1 << "]"
325 << std::endl;
326 return os << st.str();
327 }
328
329 forceinline bool
330 DFA::operator ==(const DFA& d) const {
331 if (n_states() != d.n_states())
332 return false;
333 if (n_transitions() != d.n_transitions())
334 return false;
335 if (n_symbols() != d.n_symbols())
336 return false;
337 if (max_degree() != d.max_degree())
338 return false;
339 if (final_fst() != d.final_fst())
340 return false;
341 if (final_lst() != d.final_lst())
342 return false;
343 return equal(d);
344 }
345
346 forceinline bool
347 DFA::operator !=(const DFA& d) const {
348 return !(*this == d);
349 }
350
351
352}
353
354
355// STATISTICS: int-prop
356