1/*=============================================================================
2 Copyright (c) 2001-2011 Joel de Guzman
3 Copyright (c) 2011 Bryce Lelbach
4
5 Distributed under the Boost Software License, Version 1.0. (See accompanying
6 file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7==============================================================================*/
8#if !defined(BOOST_SPIRIT_REAL_APRIL_18_2006_0850AM)
9#define BOOST_SPIRIT_REAL_APRIL_18_2006_0850AM
10
11#if defined(_MSC_VER)
12#pragma once
13#endif
14
15#include <boost/spirit/home/qi/skip_over.hpp>
16#include <boost/spirit/home/qi/detail/enable_lit.hpp>
17#include <boost/spirit/home/qi/meta_compiler.hpp>
18#include <boost/spirit/home/qi/parser.hpp>
19#include <boost/spirit/home/qi/numeric/real_policies.hpp>
20#include <boost/spirit/home/qi/numeric/numeric_utils.hpp>
21#include <boost/spirit/home/qi/numeric/detail/real_impl.hpp>
22#include <boost/spirit/home/support/common_terminals.hpp>
23#include <boost/type_traits/is_same.hpp>
24
25namespace boost { namespace spirit
26{
27 namespace qi
28 {
29 ///////////////////////////////////////////////////////////////////////
30 // forward declaration only
31 template <typename T>
32 struct real_policies;
33
34 ///////////////////////////////////////////////////////////////////////
35 // This is the class that the user can instantiate directly in
36 // order to create a customized real parser
37 template <typename T = double, typename Policies = real_policies<T> >
38 struct real_parser
39 : spirit::terminal<tag::stateful_tag<Policies, tag::double_, T> >
40 {
41 typedef tag::stateful_tag<Policies, tag::double_, T> tag_type;
42
43 real_parser() {}
44 real_parser(Policies const& p)
45 : spirit::terminal<tag_type>(p) {}
46 };
47 }
48
49 ///////////////////////////////////////////////////////////////////////////
50 // Enablers
51 ///////////////////////////////////////////////////////////////////////////
52 template <> // enables float_
53 struct use_terminal<qi::domain, tag::float_>
54 : mpl::true_ {};
55
56 template <> // enables double_
57 struct use_terminal<qi::domain, tag::double_>
58 : mpl::true_ {};
59
60 template <> // enables long_double
61 struct use_terminal<qi::domain, tag::long_double>
62 : mpl::true_ {};
63
64 ///////////////////////////////////////////////////////////////////////////
65 template <typename A0> // enables lit(n)
66 struct use_terminal<qi::domain
67 , terminal_ex<tag::lit, fusion::vector1<A0> >
68 , typename enable_if<is_same<A0, float> >::type>
69 : mpl::true_ {};
70
71 template <typename A0> // enables lit(n)
72 struct use_terminal<qi::domain
73 , terminal_ex<tag::lit, fusion::vector1<A0> >
74 , typename enable_if<is_same<A0, double> >::type>
75 : mpl::true_ {};
76
77 template <typename A0> // enables lit(n)
78 struct use_terminal<qi::domain
79 , terminal_ex<tag::lit, fusion::vector1<A0> >
80 , typename enable_if<is_same<A0, long double> >::type>
81 : mpl::true_ {};
82
83 ///////////////////////////////////////////////////////////////////////////
84 template <typename A0> // enables float_(...)
85 struct use_terminal<qi::domain
86 , terminal_ex<tag::float_, fusion::vector1<A0> >
87 > : mpl::true_ {};
88
89 template <typename A0> // enables double_(...)
90 struct use_terminal<qi::domain
91 , terminal_ex<tag::double_, fusion::vector1<A0> >
92 > : mpl::true_ {};
93
94 template <typename A0> // enables long_double(...)
95 struct use_terminal<qi::domain
96 , terminal_ex<tag::long_double, fusion::vector1<A0> >
97 > : mpl::true_ {};
98
99 template <> // enables *lazy* float_(...)
100 struct use_lazy_terminal<qi::domain, tag::float_, 1>
101 : mpl::true_ {};
102
103 template <> // enables *lazy* double_(...)
104 struct use_lazy_terminal<qi::domain, tag::double_, 1>
105 : mpl::true_ {};
106
107 template <> // enables *lazy* long_double_(...)
108 struct use_lazy_terminal<qi::domain, tag::long_double, 1>
109 : mpl::true_ {};
110
111 ///////////////////////////////////////////////////////////////////////////
112 // enables custom real_parser
113 template <typename T, typename Policies>
114 struct use_terminal<qi::domain
115 , tag::stateful_tag<Policies, tag::double_, T> >
116 : mpl::true_ {};
117
118 // enables custom real_parser(...)
119 template <typename T, typename Policies, typename A0>
120 struct use_terminal<qi::domain
121 , terminal_ex<tag::stateful_tag<Policies, tag::double_, T>
122 , fusion::vector1<A0> > >
123 : mpl::true_ {};
124
125 // enables *lazy* custom real_parser(...)
126 template <typename T, typename Policies>
127 struct use_lazy_terminal<
128 qi::domain
129 , tag::stateful_tag<Policies, tag::double_, T>
130 , 1 // arity
131 > : mpl::true_ {};
132}}
133
134namespace boost { namespace spirit { namespace qi
135{
136#ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
137 using spirit::float_;
138 using spirit::double_;
139 using spirit::long_double;
140 using spirit::lit; // lit(1.0) is equivalent to 1.0
141#endif
142
143 using spirit::float_type;
144 using spirit::double_type;
145 using spirit::long_double_type;
146 using spirit::lit_type;
147
148 ///////////////////////////////////////////////////////////////////////////
149 // This is the actual real number parser
150 ///////////////////////////////////////////////////////////////////////////
151 template <typename T, typename RealPolicies = real_policies<T> >
152 struct any_real_parser
153 : primitive_parser<any_real_parser<T, RealPolicies> >
154 {
155 template <typename Context, typename Iterator>
156 struct attribute
157 {
158 typedef T type;
159 };
160
161 template <typename Iterator, typename Context, typename Skipper>
162 bool parse(Iterator& first, Iterator const& last
163 , Context& /*context*/, Skipper const& skipper
164 , T& attr_) const
165 {
166 typedef detail::real_impl<T, RealPolicies> extract;
167 qi::skip_over(first, last, skipper);
168 return extract::parse(first, last, attr_, RealPolicies());
169 }
170
171 template <typename Iterator, typename Context
172 , typename Skipper, typename Attribute>
173 bool parse(Iterator& first, Iterator const& last
174 , Context& context, Skipper const& skipper
175 , Attribute& attr_param) const
176 {
177 // this case is called when Attribute is not T
178 T attr_;
179 if (parse(first, last, context, skipper, attr_))
180 {
181 traits::assign_to(attr_, attr_param);
182 return true;
183 }
184 return false;
185 }
186
187 template <typename Context>
188 info what(Context& /*context*/) const
189 {
190 return info("real");
191 }
192 };
193
194 template <typename T, typename RealPolicies = real_policies<T>
195 , bool no_attribute = true>
196 struct literal_real_parser
197 : primitive_parser<literal_real_parser<T, RealPolicies, no_attribute> >
198 {
199 template <typename Value>
200 literal_real_parser(Value const& n) : n_(n) {}
201
202 template <typename Context, typename Iterator>
203 struct attribute
204 : mpl::if_c<no_attribute, unused_type, T>
205 {};
206
207 template <typename Iterator, typename Context
208 , typename Skipper, typename Attribute>
209 bool parse(Iterator& first, Iterator const& last
210 , Context&, Skipper const& skipper
211 , Attribute& attr_param) const
212 {
213 typedef detail::real_impl<T, RealPolicies> extract;
214 qi::skip_over(first, last, skipper);
215
216 Iterator save = first;
217 T attr_;
218
219 if (extract::parse(first, last, attr_, RealPolicies()) &&
220 (attr_ == n_))
221 {
222 traits::assign_to(attr_, attr_param);
223 return true;
224 }
225
226 first = save;
227 return false;
228 }
229
230 template <typename Context>
231 info what(Context& /*context*/) const
232 {
233 return info("real");
234 }
235
236 T n_;
237 };
238
239 ///////////////////////////////////////////////////////////////////////////
240 // Parser generators: make_xxx function (objects)
241 ///////////////////////////////////////////////////////////////////////////
242 template <typename T, typename Policies = real_policies<T> >
243 struct make_real
244 {
245 typedef any_real_parser<T, Policies> result_type;
246
247 result_type operator()(unused_type, unused_type) const
248 {
249 return result_type();
250 }
251 };
252
253 template <typename T, typename Policies = real_policies<T> >
254 struct make_direct_real
255 {
256 typedef literal_real_parser<T, Policies, false> result_type;
257
258 template <typename Terminal>
259 result_type operator()(Terminal const& term, unused_type) const
260 {
261 return result_type(T(fusion::at_c<0>(term.args)));
262 }
263 };
264
265 template <typename T, typename Policies = real_policies<T> >
266 struct make_literal_real
267 {
268 typedef literal_real_parser<T, Policies> result_type;
269
270 template <typename Terminal>
271 result_type operator()(Terminal const& term, unused_type) const
272 {
273 return result_type(fusion::at_c<0>(term.args));
274 }
275 };
276
277 ///////////////////////////////////////////////////////////////////////////
278 template <typename Modifiers, typename A0>
279 struct make_primitive<
280 terminal_ex<tag::lit, fusion::vector1<A0> >
281 , Modifiers, typename enable_if<is_same<A0, float> >::type>
282 : make_literal_real<float> {};
283
284 template <typename Modifiers, typename A0>
285 struct make_primitive<
286 terminal_ex<tag::lit, fusion::vector1<A0> >
287 , Modifiers, typename enable_if<is_same<A0, double> >::type>
288 : make_literal_real<double> {};
289
290 template <typename Modifiers, typename A0>
291 struct make_primitive<
292 terminal_ex<tag::lit, fusion::vector1<A0> >
293 , Modifiers, typename enable_if<is_same<A0, long double> >::type>
294 : make_literal_real<long double> {};
295
296 ///////////////////////////////////////////////////////////////////////////
297 template <typename T, typename Policies, typename Modifiers>
298 struct make_primitive<
299 tag::stateful_tag<Policies, tag::double_, T>, Modifiers>
300 : make_real<T, Policies> {};
301
302 template <typename T, typename Policies, typename A0, typename Modifiers>
303 struct make_primitive<
304 terminal_ex<tag::stateful_tag<Policies, tag::double_, T>
305 , fusion::vector1<A0> >, Modifiers>
306 : make_direct_real<T, Policies> {};
307
308 ///////////////////////////////////////////////////////////////////////////
309 template <typename Modifiers>
310 struct make_primitive<tag::float_, Modifiers>
311 : make_real<float> {};
312
313 template <typename Modifiers, typename A0>
314 struct make_primitive<
315 terminal_ex<tag::float_
316 , fusion::vector1<A0> >, Modifiers>
317 : make_direct_real<float> {};
318
319 ///////////////////////////////////////////////////////////////////////////
320 template <typename Modifiers>
321 struct make_primitive<tag::double_, Modifiers>
322 : make_real<double> {};
323
324 template <typename Modifiers, typename A0>
325 struct make_primitive<
326 terminal_ex<tag::double_
327 , fusion::vector1<A0> >, Modifiers>
328 : make_direct_real<double> {};
329
330 ///////////////////////////////////////////////////////////////////////////
331 template <typename Modifiers>
332 struct make_primitive<tag::long_double, Modifiers>
333 : make_real<long double> {};
334
335 template <typename Modifiers, typename A0>
336 struct make_primitive<
337 terminal_ex<tag::long_double
338 , fusion::vector1<A0> >, Modifiers>
339 : make_direct_real<long double> {};
340}}}
341
342#endif
343

source code of boost/libs/spirit/include/boost/spirit/home/qi/numeric/real.hpp