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1 | /////////////////////////////////////////////////////////////////////////////// |
2 | // dynamic.hpp | |
3 | // | |
4 | // Copyright 2008 Eric Niebler. Distributed under the Boost | |
5 | // Software License, Version 1.0. (See accompanying file | |
6 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
7 | ||
8 | #ifndef BOOST_XPRESSIVE_DETAIL_DYNAMIC_DYNAMIC_HPP_EAN_10_04_2005 | |
9 | #define BOOST_XPRESSIVE_DETAIL_DYNAMIC_DYNAMIC_HPP_EAN_10_04_2005 | |
10 | ||
11 | // MS compatible compilers support #pragma once | |
12 | #if defined(_MSC_VER) | |
13 | # pragma once | |
14 | #endif | |
15 | ||
16 | #include <vector> | |
17 | #include <utility> | |
18 | #include <algorithm> | |
19 | #include <boost/assert.hpp> | |
20 | #include <boost/mpl/int.hpp> | |
21 | #include <boost/mpl/assert.hpp> | |
22 | #include <boost/throw_exception.hpp> | |
23 | #include <boost/type_traits/is_same.hpp> | |
24 | #include <boost/xpressive/detail/detail_fwd.hpp> | |
25 | #include <boost/xpressive/detail/core/quant_style.hpp> | |
26 | #include <boost/xpressive/detail/dynamic/matchable.hpp> | |
27 | #include <boost/xpressive/detail/dynamic/sequence.hpp> | |
28 | #include <boost/xpressive/detail/core/icase.hpp> | |
29 | ||
30 | namespace boost { namespace xpressive { namespace detail | |
31 | { | |
32 | ||
33 | /////////////////////////////////////////////////////////////////////////////// | |
34 | // invalid_xpression | |
35 | template<typename BidiIter> | |
36 | struct invalid_xpression | |
37 | : matchable_ex<BidiIter> | |
38 | { | |
39 | invalid_xpression() | |
40 | : matchable_ex<BidiIter>() | |
41 | { | |
42 | intrusive_ptr_add_ref(this); // keep alive forever | |
43 | } | |
44 | ||
45 | bool match(match_state<BidiIter> &) const | |
46 | { | |
47 | BOOST_ASSERT(false); | |
48 | return false; | |
49 | } | |
50 | }; | |
51 | ||
52 | /////////////////////////////////////////////////////////////////////////////// | |
53 | // get_invalid_xpression | |
54 | template<typename BidiIter> | |
55 | inline shared_matchable<BidiIter> const &get_invalid_xpression() | |
56 | { | |
57 | static invalid_xpression<BidiIter> const invalid_xpr; | |
58 | static intrusive_ptr<matchable_ex<BidiIter> const> const invalid_ptr(&invalid_xpr); | |
59 | static shared_matchable<BidiIter> const invalid_matchable(invalid_ptr); | |
60 | return invalid_matchable; | |
61 | } | |
62 | ||
63 | /////////////////////////////////////////////////////////////////////////////// | |
64 | // dynamic_xpression | |
65 | template<typename Matcher, typename BidiIter> | |
66 | struct dynamic_xpression | |
67 | : Matcher | |
68 | , matchable_ex<BidiIter> | |
69 | { | |
70 | typedef typename iterator_value<BidiIter>::type char_type; | |
71 | ||
72 | dynamic_xpression(Matcher const &matcher = Matcher()) | |
73 | : Matcher(matcher) | |
74 | , next_(get_invalid_xpression<BidiIter>()) | |
75 | { | |
76 | } | |
77 | ||
78 | virtual bool match(match_state<BidiIter> &state) const | |
79 | { | |
80 | return this->Matcher::match(state, *this->next_.matchable()); | |
81 | } | |
82 | ||
83 | virtual void link(xpression_linker<char_type> &linker) const | |
84 | { | |
85 | linker.accept(*static_cast<Matcher const *>(this), this->next_.matchable().get()); | |
86 | this->next_.link(linker); | |
87 | } | |
88 | ||
89 | virtual void peek(xpression_peeker<char_type> &peeker) const | |
90 | { | |
91 | this->peek_next_(peeker.accept(*static_cast<Matcher const *>(this)), peeker); | |
92 | } | |
93 | ||
94 | virtual void repeat(quant_spec const &spec, sequence<BidiIter> &seq) const | |
95 | { | |
96 | this->repeat_(spec, seq, quant_type<Matcher>(), is_same<Matcher, mark_begin_matcher>()); | |
97 | } | |
98 | ||
99 | private: | |
100 | friend struct sequence<BidiIter>; | |
101 | ||
102 | void peek_next_(mpl::true_, xpression_peeker<char_type> &peeker) const | |
103 | { | |
104 | this->next_.peek(peeker); | |
105 | } | |
106 | ||
107 | void peek_next_(mpl::false_, xpression_peeker<char_type> &) const | |
108 | { | |
109 | // no-op | |
110 | } | |
111 | ||
112 | void repeat_(quant_spec const &spec, sequence<BidiIter> &seq, mpl::int_<quant_none>, mpl::false_) const | |
113 | { | |
114 | if(quant_none == seq.quant()) | |
115 | { | |
116 | BOOST_THROW_EXCEPTION( | |
117 | regex_error(regex_constants::error_badrepeat, "expression cannot be quantified") | |
118 | ); | |
119 | } | |
120 | else | |
121 | { | |
122 | this->repeat_(spec, seq, mpl::int_<quant_variable_width>(), mpl::false_()); | |
123 | } | |
124 | } | |
125 | ||
126 | void repeat_(quant_spec const &spec, sequence<BidiIter> &seq, mpl::int_<quant_fixed_width>, mpl::false_) const | |
127 | { | |
128 | if(this->next_ == get_invalid_xpression<BidiIter>()) | |
129 | { | |
130 | make_simple_repeat(spec, seq, matcher_wrapper<Matcher>(*this)); | |
131 | } | |
132 | else | |
133 | { | |
134 | this->repeat_(spec, seq, mpl::int_<quant_variable_width>(), mpl::false_()); | |
135 | } | |
136 | } | |
137 | ||
138 | void repeat_(quant_spec const &spec, sequence<BidiIter> &seq, mpl::int_<quant_variable_width>, mpl::false_) const | |
139 | { | |
140 | if(!is_unknown(seq.width()) && seq.pure()) | |
141 | { | |
142 | make_simple_repeat(spec, seq); | |
143 | } | |
144 | else | |
145 | { | |
146 | make_repeat(spec, seq); | |
147 | } | |
148 | } | |
149 | ||
150 | void repeat_(quant_spec const &spec, sequence<BidiIter> &seq, mpl::int_<quant_fixed_width>, mpl::true_) const | |
151 | { | |
152 | make_repeat(spec, seq, this->mark_number_); | |
153 | } | |
154 | ||
155 | shared_matchable<BidiIter> next_; | |
156 | }; | |
157 | ||
158 | /////////////////////////////////////////////////////////////////////////////// | |
159 | // make_dynamic | |
160 | template<typename BidiIter, typename Matcher> | |
161 | inline sequence<BidiIter> make_dynamic(Matcher const &matcher) | |
162 | { | |
163 | typedef dynamic_xpression<Matcher, BidiIter> xpression_type; | |
164 | intrusive_ptr<xpression_type> xpr(new xpression_type(matcher)); | |
165 | return sequence<BidiIter>(xpr); | |
166 | } | |
167 | ||
168 | /////////////////////////////////////////////////////////////////////////////// | |
169 | // alternates_vector | |
170 | template<typename BidiIter> | |
171 | struct alternates_vector | |
172 | : std::vector<shared_matchable<BidiIter> > | |
173 | { | |
174 | BOOST_STATIC_CONSTANT(std::size_t, width = unknown_width::value); | |
175 | BOOST_STATIC_CONSTANT(bool, pure = false); | |
176 | }; | |
177 | ||
178 | /////////////////////////////////////////////////////////////////////////////// | |
179 | // matcher_wrapper | |
180 | template<typename Matcher> | |
181 | struct matcher_wrapper | |
182 | : Matcher | |
183 | { | |
184 | matcher_wrapper(Matcher const &matcher = Matcher()) | |
185 | : Matcher(matcher) | |
186 | { | |
187 | } | |
188 | ||
189 | template<typename BidiIter> | |
190 | bool match(match_state<BidiIter> &state) const | |
191 | { | |
192 | return this->Matcher::match(state, matcher_wrapper<true_matcher>()); | |
193 | } | |
194 | ||
195 | template<typename Char> | |
196 | void link(xpression_linker<Char> &linker) const | |
197 | { | |
198 | linker.accept(*static_cast<Matcher const *>(this), 0); | |
199 | } | |
200 | ||
201 | template<typename Char> | |
202 | void peek(xpression_peeker<Char> &peeker) const | |
203 | { | |
204 | peeker.accept(*static_cast<Matcher const *>(this)); | |
205 | } | |
206 | }; | |
207 | ||
208 | ////////////////////////////////////////////////////////////////////////// | |
209 | // make_simple_repeat | |
210 | template<typename BidiIter, typename Xpr> | |
211 | inline void | |
212 | make_simple_repeat(quant_spec const &spec, sequence<BidiIter> &seq, Xpr const &xpr) | |
213 | { | |
214 | if(spec.greedy_) | |
215 | { | |
216 | simple_repeat_matcher<Xpr, mpl::true_> quant(xpr, spec.min_, spec.max_, seq.width().value()); | |
217 | seq = make_dynamic<BidiIter>(quant); | |
218 | } | |
219 | else | |
220 | { | |
221 | simple_repeat_matcher<Xpr, mpl::false_> quant(xpr, spec.min_, spec.max_, seq.width().value()); | |
222 | seq = make_dynamic<BidiIter>(quant); | |
223 | } | |
224 | } | |
225 | ||
226 | ////////////////////////////////////////////////////////////////////////// | |
227 | // make_simple_repeat | |
228 | template<typename BidiIter> | |
229 | inline void | |
230 | make_simple_repeat(quant_spec const &spec, sequence<BidiIter> &seq) | |
231 | { | |
232 | seq += make_dynamic<BidiIter>(true_matcher()); | |
233 | make_simple_repeat(spec, seq, seq.xpr()); | |
234 | } | |
235 | ||
236 | ////////////////////////////////////////////////////////////////////////// | |
237 | // make_optional | |
238 | template<typename BidiIter> | |
239 | inline void | |
240 | make_optional(quant_spec const &spec, sequence<BidiIter> &seq) | |
241 | { | |
242 | typedef shared_matchable<BidiIter> xpr_type; | |
243 | seq += make_dynamic<BidiIter>(alternate_end_matcher()); | |
244 | if(spec.greedy_) | |
245 | { | |
246 | optional_matcher<xpr_type, mpl::true_> opt(seq.xpr()); | |
247 | seq = make_dynamic<BidiIter>(opt); | |
248 | } | |
249 | else | |
250 | { | |
251 | optional_matcher<xpr_type, mpl::false_> opt(seq.xpr()); | |
252 | seq = make_dynamic<BidiIter>(opt); | |
253 | } | |
254 | } | |
255 | ||
256 | ////////////////////////////////////////////////////////////////////////// | |
257 | // make_optional | |
258 | template<typename BidiIter> | |
259 | inline void | |
260 | make_optional(quant_spec const &spec, sequence<BidiIter> &seq, int mark_nbr) | |
261 | { | |
262 | typedef shared_matchable<BidiIter> xpr_type; | |
263 | seq += make_dynamic<BidiIter>(alternate_end_matcher()); | |
264 | if(spec.greedy_) | |
265 | { | |
266 | optional_mark_matcher<xpr_type, mpl::true_> opt(seq.xpr(), mark_nbr); | |
267 | seq = make_dynamic<BidiIter>(opt); | |
268 | } | |
269 | else | |
270 | { | |
271 | optional_mark_matcher<xpr_type, mpl::false_> opt(seq.xpr(), mark_nbr); | |
272 | seq = make_dynamic<BidiIter>(opt); | |
273 | } | |
274 | } | |
275 | ||
276 | ////////////////////////////////////////////////////////////////////////// | |
277 | // make_repeat | |
278 | template<typename BidiIter> | |
279 | inline void | |
280 | make_repeat(quant_spec const &spec, sequence<BidiIter> &seq) | |
281 | { | |
282 | // only bother creating a repeater if max is greater than one | |
283 | if(1 < spec.max_) | |
284 | { | |
285 | // create a hidden mark so this expression can be quantified | |
286 | int mark_nbr = -static_cast<int>(++*spec.hidden_mark_count_); | |
287 | seq = make_dynamic<BidiIter>(mark_begin_matcher(mark_nbr)) + seq | |
288 | + make_dynamic<BidiIter>(mark_end_matcher(mark_nbr)); | |
289 | make_repeat(spec, seq, mark_nbr); | |
290 | return; | |
291 | } | |
292 | ||
293 | // if min is 0, the repeat must be made optional | |
294 | if(0 == spec.min_) | |
295 | { | |
296 | make_optional(spec, seq); | |
297 | } | |
298 | } | |
299 | ||
300 | ////////////////////////////////////////////////////////////////////////// | |
301 | // make_repeat | |
302 | template<typename BidiIter> | |
303 | inline void | |
304 | make_repeat(quant_spec const &spec, sequence<BidiIter> &seq, int mark_nbr) | |
305 | { | |
306 | BOOST_ASSERT(spec.max_); // we should never get here if max is 0 | |
307 | ||
308 | // only bother creating a repeater if max is greater than one | |
309 | if(1 < spec.max_) | |
310 | { | |
311 | // TODO: statically bind the repeat matchers to the mark matchers for better perf | |
312 | unsigned int min = spec.min_ ? spec.min_ : 1U; | |
313 | repeat_begin_matcher repeat_begin(mark_nbr); | |
314 | if(spec.greedy_) | |
315 | { | |
316 | repeat_end_matcher<mpl::true_> repeat_end(mark_nbr, min, spec.max_); | |
317 | seq = make_dynamic<BidiIter>(repeat_begin) + seq | |
318 | + make_dynamic<BidiIter>(repeat_end); | |
319 | } | |
320 | else | |
321 | { | |
322 | repeat_end_matcher<mpl::false_> repeat_end(mark_nbr, min, spec.max_); | |
323 | seq = make_dynamic<BidiIter>(repeat_begin) + seq | |
324 | + make_dynamic<BidiIter>(repeat_end); | |
325 | } | |
326 | } | |
327 | ||
328 | // if min is 0, the repeat must be made optional | |
329 | if(0 == spec.min_) | |
330 | { | |
331 | make_optional(spec, seq, mark_nbr); | |
332 | } | |
333 | } | |
334 | ||
335 | }}} // namespace boost::xpressive::detail | |
336 | ||
337 | #endif |