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1 | // tokeniser_helper.hpp |
2 | // Copyright (c) 2007-2009 Ben Hanson (http://www.benhanson.net/) | |
3 | // | |
4 | // Distributed under the Boost Software License, Version 1.0. (See accompanying | |
5 | // file licence_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
f67539c2 TL |
6 | #ifndef BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TOKENISER_RE_TOKENISER_HELPER_HPP |
7 | #define BOOST_SPIRIT_SUPPORT_DETAIL_LEXER_PARSER_TOKENISER_RE_TOKENISER_HELPER_HPP | |
7c673cae FG |
8 | |
9 | #include "../../char_traits.hpp" | |
10 | // strlen() | |
11 | #include <cstring> | |
12 | #include "../../size_t.hpp" | |
13 | #include "re_tokeniser_state.hpp" | |
14 | ||
15 | namespace boost | |
16 | { | |
17 | namespace lexer | |
18 | { | |
19 | namespace detail | |
20 | { | |
21 | template<typename CharT, typename Traits = char_traits<CharT> > | |
22 | class basic_re_tokeniser_helper | |
23 | { | |
24 | public: | |
25 | typedef basic_re_tokeniser_state<CharT> state; | |
26 | typedef std::basic_string<CharT> string; | |
27 | ||
28 | static const CharT *escape_sequence (state &state_, CharT &ch_, | |
29 | std::size_t &str_len_) | |
30 | { | |
31 | bool eos_ = state_.eos (); | |
32 | ||
33 | if (eos_) | |
34 | { | |
35 | throw runtime_error ("Unexpected end of regex " | |
36 | "following '\\'."); | |
37 | } | |
38 | ||
39 | const CharT *str_ = charset_shortcut (*state_._curr, str_len_); | |
40 | ||
41 | if (str_) | |
42 | { | |
43 | state_.increment (); | |
44 | } | |
45 | else | |
46 | { | |
47 | ch_ = chr (state_); | |
48 | } | |
49 | ||
50 | return str_; | |
51 | } | |
52 | ||
53 | // This function can call itself. | |
54 | static void charset (state &state_, string &chars_, bool &negated_) | |
55 | { | |
56 | CharT ch_ = 0; | |
57 | bool eos_ = state_.next (ch_); | |
58 | ||
59 | if (eos_) | |
60 | { | |
61 | // Pointless returning index if at end of string | |
62 | throw runtime_error ("Unexpected end of regex " | |
63 | "following '['."); | |
64 | } | |
65 | ||
66 | negated_ = ch_ == '^'; | |
67 | ||
68 | if (negated_) | |
69 | { | |
70 | eos_ = state_.next (ch_); | |
71 | ||
72 | if (eos_) | |
73 | { | |
74 | // Pointless returning index if at end of string | |
75 | throw runtime_error ("Unexpected end of regex " | |
76 | "following '^'."); | |
77 | } | |
78 | } | |
79 | ||
80 | bool chset_ = false; | |
81 | CharT prev_ = 0; | |
82 | ||
83 | while (ch_ != ']') | |
84 | { | |
85 | if (ch_ == '\\') | |
86 | { | |
87 | std::size_t str_len_ = 0; | |
88 | const CharT *str_ = escape_sequence (state_, prev_, str_len_); | |
89 | ||
90 | chset_ = str_ != 0; | |
91 | ||
92 | if (chset_) | |
93 | { | |
94 | state temp_state_ (str_ + 1, str_ + str_len_, | |
95 | state_._flags, state_._locale); | |
96 | string temp_chars_; | |
97 | bool temp_negated_ = false; | |
98 | ||
99 | charset (temp_state_, temp_chars_, temp_negated_); | |
100 | ||
101 | if (negated_ != temp_negated_) | |
102 | { | |
103 | std::ostringstream ss_; | |
104 | ||
105 | ss_ << "Mismatch in charset negation preceding " | |
106 | "index " << state_.index () << '.'; | |
107 | throw runtime_error (ss_.str ().c_str ()); | |
108 | } | |
109 | ||
110 | chars_ += temp_chars_; | |
111 | } | |
112 | } | |
113 | /* | |
114 | else if (ch_ == '[' && !state_.eos () && *state_._curr == ':') | |
115 | { | |
116 | // TODO: POSIX charsets | |
117 | } | |
118 | */ | |
119 | else | |
120 | { | |
121 | chset_ = false; | |
122 | prev_ = ch_; | |
123 | } | |
124 | ||
125 | eos_ = state_.next (ch_); | |
126 | ||
127 | // Covers preceding if, else if and else | |
128 | if (eos_) | |
129 | { | |
130 | // Pointless returning index if at end of string | |
131 | throw runtime_error ("Unexpected end of regex " | |
132 | "(missing ']')."); | |
133 | } | |
134 | ||
135 | if (ch_ == '-') | |
136 | { | |
137 | charset_range (chset_, state_, eos_, ch_, prev_, chars_); | |
138 | } | |
139 | else if (!chset_) | |
140 | { | |
141 | if ((state_._flags & icase) && | |
142 | (std::isupper (prev_, state_._locale) || | |
143 | std::islower (prev_, state_._locale))) | |
144 | { | |
145 | CharT upper_ = std::toupper (prev_, state_._locale); | |
146 | CharT lower_ = std::tolower (prev_, state_._locale); | |
147 | ||
148 | chars_ += upper_; | |
149 | chars_ += lower_; | |
150 | } | |
151 | else | |
152 | { | |
153 | chars_ += prev_; | |
154 | } | |
155 | } | |
156 | } | |
157 | ||
158 | if (!negated_ && chars_.empty ()) | |
159 | { | |
160 | throw runtime_error ("Empty charsets not allowed."); | |
161 | } | |
162 | } | |
163 | ||
164 | static CharT chr (state &state_) | |
165 | { | |
166 | CharT ch_ = 0; | |
167 | ||
168 | // eos_ has already been checked for. | |
169 | switch (*state_._curr) | |
170 | { | |
171 | case '0': | |
172 | case '1': | |
173 | case '2': | |
174 | case '3': | |
175 | case '4': | |
176 | case '5': | |
177 | case '6': | |
178 | case '7': | |
179 | ch_ = decode_octal (state_); | |
180 | break; | |
181 | case 'a': | |
182 | ch_ = '\a'; | |
183 | state_.increment (); | |
184 | break; | |
185 | case 'b': | |
186 | ch_ = '\b'; | |
187 | state_.increment (); | |
188 | break; | |
189 | case 'c': | |
190 | ch_ = decode_control_char (state_); | |
191 | break; | |
192 | case 'e': | |
193 | ch_ = 27; // '\e' not recognised by compiler | |
194 | state_.increment (); | |
195 | break; | |
196 | case 'f': | |
197 | ch_ = '\f'; | |
198 | state_.increment (); | |
199 | break; | |
200 | case 'n': | |
201 | ch_ = '\n'; | |
202 | state_.increment (); | |
203 | break; | |
204 | case 'r': | |
205 | ch_ = '\r'; | |
206 | state_.increment (); | |
207 | break; | |
208 | case 't': | |
209 | ch_ = '\t'; | |
210 | state_.increment (); | |
211 | break; | |
212 | case 'v': | |
213 | ch_ = '\v'; | |
214 | state_.increment (); | |
215 | break; | |
216 | case 'x': | |
217 | ch_ = decode_hex (state_); | |
218 | break; | |
219 | default: | |
220 | ch_ = *state_._curr; | |
221 | state_.increment (); | |
222 | break; | |
223 | } | |
224 | ||
225 | return ch_; | |
226 | } | |
227 | ||
228 | private: | |
229 | static const char *charset_shortcut (const char ch_, | |
230 | std::size_t &str_len_) | |
231 | { | |
232 | const char *str_ = 0; | |
233 | ||
234 | switch (ch_) | |
235 | { | |
236 | case 'd': | |
237 | str_ = "[0-9]"; | |
238 | break; | |
239 | case 'D': | |
240 | str_ = "[^0-9]"; | |
241 | break; | |
242 | case 's': | |
243 | str_ = "[ \t\n\r\f\v]"; | |
244 | break; | |
245 | case 'S': | |
246 | str_ = "[^ \t\n\r\f\v]"; | |
247 | break; | |
248 | case 'w': | |
249 | str_ = "[_0-9A-Za-z]"; | |
250 | break; | |
251 | case 'W': | |
252 | str_ = "[^_0-9A-Za-z]"; | |
253 | break; | |
254 | } | |
255 | ||
256 | if (str_) | |
257 | { | |
258 | // Some systems have strlen in namespace std. | |
259 | using namespace std; | |
260 | ||
261 | str_len_ = strlen (str_); | |
262 | } | |
263 | else | |
264 | { | |
265 | str_len_ = 0; | |
266 | } | |
267 | ||
268 | return str_; | |
269 | } | |
270 | ||
271 | static const wchar_t *charset_shortcut (const wchar_t ch_, | |
272 | std::size_t &str_len_) | |
273 | { | |
274 | const wchar_t *str_ = 0; | |
275 | ||
276 | switch (ch_) | |
277 | { | |
278 | case 'd': | |
279 | str_ = L"[0-9]"; | |
280 | break; | |
281 | case 'D': | |
282 | str_ = L"[^0-9]"; | |
283 | break; | |
284 | case 's': | |
285 | str_ = L"[ \t\n\r\f\v]"; | |
286 | break; | |
287 | case 'S': | |
288 | str_ = L"[^ \t\n\r\f\v]"; | |
289 | break; | |
290 | case 'w': | |
291 | str_ = L"[_0-9A-Za-z]"; | |
292 | break; | |
293 | case 'W': | |
294 | str_ = L"[^_0-9A-Za-z]"; | |
295 | break; | |
296 | } | |
297 | ||
298 | if (str_) | |
299 | { | |
300 | // Some systems have wcslen in namespace std. | |
301 | using namespace std; | |
302 | ||
303 | str_len_ = wcslen (str_); | |
304 | } | |
305 | else | |
306 | { | |
307 | str_len_ = 0; | |
308 | } | |
309 | ||
310 | return str_; | |
311 | } | |
312 | ||
313 | static CharT decode_octal (state &state_) | |
314 | { | |
315 | std::size_t accumulator_ = 0; | |
316 | CharT ch_ = *state_._curr; | |
317 | unsigned short count_ = 3; | |
318 | bool eos_ = false; | |
319 | ||
320 | for (;;) | |
321 | { | |
322 | accumulator_ *= 8; | |
323 | accumulator_ += ch_ - '0'; | |
324 | --count_; | |
325 | state_.increment (); | |
326 | eos_ = state_.eos (); | |
327 | ||
328 | if (!count_ || eos_) break; | |
329 | ||
330 | ch_ = *state_._curr; | |
331 | ||
332 | // Don't consume invalid chars! | |
333 | if (ch_ < '0' || ch_ > '7') | |
334 | { | |
335 | break; | |
336 | } | |
337 | } | |
338 | ||
339 | return static_cast<CharT> (accumulator_); | |
340 | } | |
341 | ||
342 | static CharT decode_control_char (state &state_) | |
343 | { | |
344 | // Skip over 'c' | |
345 | state_.increment (); | |
346 | ||
347 | CharT ch_ = 0; | |
348 | bool eos_ = state_.next (ch_); | |
349 | ||
350 | if (eos_) | |
351 | { | |
352 | // Pointless returning index if at end of string | |
353 | throw runtime_error ("Unexpected end of regex following \\c."); | |
354 | } | |
355 | else | |
356 | { | |
357 | if (ch_ >= 'a' && ch_ <= 'z') | |
358 | { | |
359 | ch_ -= 'a' - 1; | |
360 | } | |
361 | else if (ch_ >= 'A' && ch_ <= 'Z') | |
362 | { | |
363 | ch_ -= 'A' - 1; | |
364 | } | |
365 | else if (ch_ == '@') | |
366 | { | |
367 | // Apparently... | |
368 | ch_ = 0; | |
369 | } | |
370 | else | |
371 | { | |
372 | std::ostringstream ss_; | |
373 | ||
374 | ss_ << "Invalid control char at index " << | |
375 | state_.index () - 1 << '.'; | |
376 | throw runtime_error (ss_.str ().c_str ()); | |
377 | } | |
378 | } | |
379 | ||
380 | return ch_; | |
381 | } | |
382 | ||
383 | static CharT decode_hex (state &state_) | |
384 | { | |
385 | // Skip over 'x' | |
386 | state_.increment (); | |
387 | ||
388 | CharT ch_ = 0; | |
389 | bool eos_ = state_.next (ch_); | |
390 | ||
391 | if (eos_) | |
392 | { | |
393 | // Pointless returning index if at end of string | |
394 | throw runtime_error ("Unexpected end of regex following \\x."); | |
395 | } | |
396 | ||
397 | if (!((ch_ >= '0' && ch_ <= '9') || (ch_ >= 'a' && ch_ <= 'f') || | |
398 | (ch_ >= 'A' && ch_ <= 'F'))) | |
399 | { | |
400 | std::ostringstream ss_; | |
401 | ||
402 | ss_ << "Illegal char following \\x at index " << | |
403 | state_.index () - 1 << '.'; | |
404 | throw runtime_error (ss_.str ().c_str ()); | |
405 | } | |
406 | ||
407 | std::size_t hex_ = 0; | |
408 | ||
409 | do | |
410 | { | |
411 | hex_ *= 16; | |
412 | ||
413 | if (ch_ >= '0' && ch_ <= '9') | |
414 | { | |
415 | hex_ += ch_ - '0'; | |
416 | } | |
417 | else if (ch_ >= 'a' && ch_ <= 'f') | |
418 | { | |
419 | hex_ += 10 + (ch_ - 'a'); | |
420 | } | |
421 | else | |
422 | { | |
423 | hex_ += 10 + (ch_ - 'A'); | |
424 | } | |
425 | ||
426 | eos_ = state_.eos (); | |
427 | ||
428 | if (!eos_) | |
429 | { | |
430 | ch_ = *state_._curr; | |
431 | ||
432 | // Don't consume invalid chars! | |
433 | if (((ch_ >= '0' && ch_ <= '9') || | |
434 | (ch_ >= 'a' && ch_ <= 'f') || (ch_ >= 'A' && ch_ <= 'F'))) | |
435 | { | |
436 | state_.increment (); | |
437 | } | |
438 | else | |
439 | { | |
440 | eos_ = true; | |
441 | } | |
442 | } | |
443 | } while (!eos_); | |
444 | ||
445 | return static_cast<CharT> (hex_); | |
446 | } | |
447 | ||
448 | static void charset_range (const bool chset_, state &state_, bool &eos_, | |
449 | CharT &ch_, const CharT prev_, string &chars_) | |
450 | { | |
451 | if (chset_) | |
452 | { | |
453 | std::ostringstream ss_; | |
454 | ||
455 | ss_ << "Charset cannot form start of range preceding " | |
456 | "index " << state_.index () - 1 << '.'; | |
457 | throw runtime_error (ss_.str ().c_str ()); | |
458 | } | |
459 | ||
460 | eos_ = state_.next (ch_); | |
461 | ||
462 | if (eos_) | |
463 | { | |
464 | // Pointless returning index if at end of string | |
465 | throw runtime_error ("Unexpected end of regex " | |
466 | "following '-'."); | |
467 | } | |
468 | ||
469 | CharT curr_ = 0; | |
470 | ||
471 | if (ch_ == '\\') | |
472 | { | |
473 | std::size_t str_len_ = 0; | |
474 | ||
475 | if (escape_sequence (state_, curr_, str_len_)) | |
476 | { | |
477 | std::ostringstream ss_; | |
478 | ||
479 | ss_ << "Charset cannot form end of range preceding index " | |
480 | << state_.index () << '.'; | |
481 | throw runtime_error (ss_.str ().c_str ()); | |
482 | } | |
483 | } | |
484 | /* | |
485 | else if (ch_ == '[' && !state_.eos () && *state_._curr == ':') | |
486 | { | |
487 | std::ostringstream ss_; | |
488 | ||
489 | ss_ << "POSIX char class cannot form end of range at " | |
490 | "index " << state_.index () - 1 << '.'; | |
491 | throw runtime_error (ss_.str ().c_str ()); | |
492 | } | |
493 | */ | |
494 | else | |
495 | { | |
496 | curr_ = ch_; | |
497 | } | |
498 | ||
499 | eos_ = state_.next (ch_); | |
500 | ||
501 | // Covers preceding if and else | |
502 | if (eos_) | |
503 | { | |
504 | // Pointless returning index if at end of string | |
505 | throw runtime_error ("Unexpected end of regex " | |
506 | "(missing ']')."); | |
507 | } | |
508 | ||
509 | std::size_t start_ = static_cast<typename Traits::index_type> (prev_); | |
510 | std::size_t end_ = static_cast<typename Traits::index_type> (curr_); | |
511 | ||
512 | // Semanic check | |
513 | if (end_ < start_) | |
514 | { | |
515 | std::ostringstream ss_; | |
516 | ||
517 | ss_ << "Invalid range in charset preceding index " << | |
518 | state_.index () - 1 << '.'; | |
519 | throw runtime_error (ss_.str ().c_str ()); | |
520 | } | |
521 | ||
522 | chars_.reserve (chars_.size () + (end_ + 1 - start_)); | |
523 | ||
524 | for (; start_ <= end_; ++start_) | |
525 | { | |
526 | CharT ch_ = static_cast<CharT> (start_); | |
527 | ||
528 | if ((state_._flags & icase) && | |
529 | (std::isupper (ch_, state_._locale) || | |
530 | std::islower (ch_, state_._locale))) | |
531 | { | |
532 | CharT upper_ = std::toupper (ch_, state_._locale); | |
533 | CharT lower_ = std::tolower (ch_, state_._locale); | |
534 | ||
535 | chars_ += (upper_); | |
536 | chars_ += (lower_); | |
537 | } | |
538 | else | |
539 | { | |
540 | chars_ += (ch_); | |
541 | } | |
542 | } | |
543 | } | |
544 | }; | |
545 | } | |
546 | } | |
547 | } | |
548 | ||
549 | #endif |