bool.hpp 11 KB

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  1. /*=============================================================================
  2. Copyright (c) 2001-2011 Hartmut Kaiser
  3. Copyright (c) 2011 Bryce Lelbach
  4. Distributed under the Boost Software License, Version 1.0. (See accompanying
  5. file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  6. ==============================================================================*/
  7. #if !defined(SPIRIT_QI_BOOL_SEP_29_2009_0709AM)
  8. #define SPIRIT_QI_BOOL_SEP_29_2009_0709AM
  9. #if defined(_MSC_VER)
  10. #pragma once
  11. #endif
  12. #include <boost/spirit/home/qi/skip_over.hpp>
  13. #include <boost/spirit/home/qi/detail/enable_lit.hpp>
  14. #include <boost/spirit/home/qi/meta_compiler.hpp>
  15. #include <boost/spirit/home/qi/parser.hpp>
  16. #include <boost/spirit/home/qi/numeric/bool_policies.hpp>
  17. #include <boost/spirit/home/support/common_terminals.hpp>
  18. #include <boost/mpl/assert.hpp>
  19. #include <boost/detail/workaround.hpp>
  20. #include <boost/type_traits/is_same.hpp>
  21. namespace boost { namespace spirit
  22. {
  23. namespace qi
  24. {
  25. ///////////////////////////////////////////////////////////////////////
  26. // forward declaration only
  27. template <typename T>
  28. struct bool_policies;
  29. ///////////////////////////////////////////////////////////////////////
  30. // This is the class that the user can instantiate directly in
  31. // order to create a customized bool parser
  32. template <typename T, typename BoolPolicies = bool_policies<T> >
  33. struct bool_parser
  34. : spirit::terminal<tag::stateful_tag<BoolPolicies, tag::bool_, T> >
  35. {
  36. typedef tag::stateful_tag<BoolPolicies, tag::bool_, T> tag_type;
  37. bool_parser() {}
  38. bool_parser(BoolPolicies const& data)
  39. : spirit::terminal<tag_type>(data) {}
  40. };
  41. }
  42. ///////////////////////////////////////////////////////////////////////////
  43. // Enablers
  44. ///////////////////////////////////////////////////////////////////////////
  45. template <> // enables bool_
  46. struct use_terminal<qi::domain, tag::bool_>
  47. : mpl::true_ {};
  48. template <> // enables true_
  49. struct use_terminal<qi::domain, tag::true_>
  50. : mpl::true_ {};
  51. template <> // enables false_
  52. struct use_terminal<qi::domain, tag::false_>
  53. : mpl::true_ {};
  54. ///////////////////////////////////////////////////////////////////////////
  55. template <typename A0> // enables lit(...)
  56. struct use_terminal<qi::domain
  57. , terminal_ex<tag::lit, fusion::vector1<A0> >
  58. , typename enable_if<is_same<A0, bool> >::type>
  59. : mpl::true_ {};
  60. ///////////////////////////////////////////////////////////////////////////
  61. template <typename A0> // enables bool_(...)
  62. struct use_terminal<qi::domain
  63. , terminal_ex<tag::bool_, fusion::vector1<A0> >
  64. > : mpl::true_ {};
  65. template <> // enables *lazy* bool_(...)
  66. struct use_lazy_terminal<qi::domain, tag::bool_, 1>
  67. : mpl::true_ {};
  68. ///////////////////////////////////////////////////////////////////////////
  69. // enables any custom bool_parser
  70. template <typename T, typename BoolPolicies>
  71. struct use_terminal<qi::domain
  72. , tag::stateful_tag<BoolPolicies, tag::bool_, T> >
  73. : mpl::true_ {};
  74. // enables any custom bool_parser(...)
  75. template <typename T, typename BoolPolicies, typename A0>
  76. struct use_terminal<qi::domain
  77. , terminal_ex<tag::stateful_tag<BoolPolicies, tag::bool_, T>
  78. , fusion::vector1<A0> > >
  79. : mpl::true_ {};
  80. // enables *lazy* custom bool_parser(...)
  81. template <typename T, typename BoolPolicies>
  82. struct use_lazy_terminal<
  83. qi::domain
  84. , tag::stateful_tag<BoolPolicies, tag::bool_, T>
  85. , 1 // arity
  86. > : mpl::true_ {};
  87. }}
  88. namespace boost { namespace spirit { namespace qi
  89. {
  90. #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
  91. using spirit::bool_;
  92. using spirit::true_;
  93. using spirit::false_;
  94. using spirit::lit; // lit(true) is equivalent to true
  95. #endif
  96. using spirit::bool_type;
  97. using spirit::true_type;
  98. using spirit::false_type;
  99. using spirit::lit_type;
  100. namespace detail
  101. {
  102. template <typename T, typename BoolPolicies>
  103. struct bool_impl
  104. {
  105. template <typename Iterator, typename Attribute>
  106. static bool parse(Iterator& first, Iterator const& last
  107. , Attribute& attr, BoolPolicies const& p, bool allow_true = true
  108. , bool disallow_false = false)
  109. {
  110. if (first == last)
  111. return false;
  112. #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
  113. p; // suppresses warning: C4100: 'p' : unreferenced formal parameter
  114. #endif
  115. return (allow_true && p.parse_true(first, last, attr)) ||
  116. (!disallow_false && p.parse_false(first, last, attr));
  117. }
  118. };
  119. }
  120. ///////////////////////////////////////////////////////////////////////////
  121. // This actual boolean parser
  122. ///////////////////////////////////////////////////////////////////////////
  123. template <typename T, typename BoolPolicies = bool_policies<T> >
  124. struct any_bool_parser
  125. : primitive_parser<any_bool_parser<T, BoolPolicies> >
  126. {
  127. template <typename Context, typename Iterator>
  128. struct attribute
  129. {
  130. typedef T type;
  131. };
  132. template <typename Iterator, typename Context
  133. , typename Skipper, typename Attribute>
  134. bool parse(Iterator& first, Iterator const& last
  135. , Context& /*context*/, Skipper const& skipper
  136. , Attribute& attr_) const
  137. {
  138. typedef detail::bool_impl<T, BoolPolicies> extract;
  139. qi::skip_over(first, last, skipper);
  140. return extract::parse(first, last, attr_, BoolPolicies());
  141. }
  142. template <typename Context>
  143. info what(Context& /*context*/) const
  144. {
  145. return info("boolean");
  146. }
  147. };
  148. template <typename T, typename BoolPolicies = bool_policies<T>
  149. , bool no_attribute = true>
  150. struct literal_bool_parser
  151. : primitive_parser<literal_bool_parser<T, BoolPolicies, no_attribute> >
  152. {
  153. template <typename Value>
  154. literal_bool_parser(Value const& n) : n_(n) {}
  155. template <typename Context, typename Iterator>
  156. struct attribute
  157. : mpl::if_c<no_attribute, unused_type, T>
  158. {};
  159. template <typename Iterator, typename Context
  160. , typename Skipper, typename Attribute>
  161. bool parse(Iterator& first, Iterator const& last
  162. , Context& /*context*/, Skipper const& skipper
  163. , Attribute& attr_) const
  164. {
  165. typedef detail::bool_impl<T, BoolPolicies> extract;
  166. qi::skip_over(first, last, skipper);
  167. return extract::parse(first, last, attr_, BoolPolicies(), n_, n_);
  168. }
  169. template <typename Context>
  170. info what(Context& /*context*/) const
  171. {
  172. return info("boolean");
  173. }
  174. T n_;
  175. };
  176. ///////////////////////////////////////////////////////////////////////////
  177. // Parser generators: make_xxx function (objects)
  178. ///////////////////////////////////////////////////////////////////////////
  179. template <typename T, typename Modifiers
  180. , typename Policies = bool_policies<T> >
  181. struct make_bool
  182. {
  183. typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
  184. no_case;
  185. typedef typename mpl::if_<
  186. mpl::and_<
  187. no_case
  188. , is_same<bool_policies<T>, Policies>
  189. >
  190. , any_bool_parser<T, no_case_bool_policies<T> >
  191. , any_bool_parser<T, Policies> >::type
  192. result_type;
  193. result_type operator()(unused_type, unused_type) const
  194. {
  195. return result_type();
  196. }
  197. };
  198. template <typename T, typename Modifiers
  199. , typename Policies = bool_policies<T> >
  200. struct make_direct_bool
  201. {
  202. typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
  203. no_case;
  204. typedef typename mpl::if_<
  205. mpl::and_<
  206. no_case
  207. , is_same<bool_policies<T>, Policies>
  208. >
  209. , literal_bool_parser<T, no_case_bool_policies<T>, false>
  210. , literal_bool_parser<T, Policies, false> >::type
  211. result_type;
  212. template <typename Terminal>
  213. result_type operator()(Terminal const& term, unused_type) const
  214. {
  215. return result_type(fusion::at_c<0>(term.args));
  216. }
  217. };
  218. template <typename T, typename Modifiers, bool b
  219. , typename Policies = bool_policies<T> >
  220. struct make_predefined_direct_bool
  221. {
  222. typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
  223. no_case;
  224. typedef typename mpl::if_<
  225. mpl::and_<
  226. no_case
  227. , is_same<bool_policies<T>, Policies>
  228. >
  229. , literal_bool_parser<T, no_case_bool_policies<T>, false>
  230. , literal_bool_parser<T, Policies, false> >::type
  231. result_type;
  232. result_type operator()(unused_type, unused_type) const
  233. {
  234. return result_type(b);
  235. }
  236. };
  237. template <typename T, typename Modifiers
  238. , typename Policies = bool_policies<T> >
  239. struct make_literal_bool
  240. {
  241. typedef has_modifier<Modifiers, tag::char_code_base<tag::no_case> >
  242. no_case;
  243. typedef typename mpl::if_<
  244. mpl::and_<
  245. no_case
  246. , is_same<bool_policies<T>, Policies>
  247. >
  248. , literal_bool_parser<T, no_case_bool_policies<T> >
  249. , literal_bool_parser<T, Policies> >::type
  250. result_type;
  251. template <typename Terminal>
  252. result_type operator()(Terminal const& term, unused_type) const
  253. {
  254. return result_type(fusion::at_c<0>(term.args));
  255. }
  256. };
  257. ///////////////////////////////////////////////////////////////////////////
  258. template <typename Modifiers, typename A0>
  259. struct make_primitive<
  260. terminal_ex<tag::lit, fusion::vector1<A0> >
  261. , Modifiers, typename enable_if<is_same<A0, bool> >::type>
  262. : make_literal_bool<bool, Modifiers> {};
  263. ///////////////////////////////////////////////////////////////////////////
  264. template <typename Modifiers>
  265. struct make_primitive<tag::false_, Modifiers>
  266. : make_predefined_direct_bool<bool, Modifiers, false>
  267. {};
  268. template <typename Modifiers>
  269. struct make_primitive<tag::true_, Modifiers>
  270. : make_predefined_direct_bool<bool, Modifiers, true>
  271. {};
  272. ///////////////////////////////////////////////////////////////////////////
  273. template <typename T, typename Policies, typename Modifiers>
  274. struct make_primitive<
  275. tag::stateful_tag<Policies, tag::bool_, T>, Modifiers>
  276. : make_bool<T, Modifiers, Policies> {};
  277. template <typename T, typename Policies, typename A0, typename Modifiers>
  278. struct make_primitive<
  279. terminal_ex<tag::stateful_tag<Policies, tag::bool_, T>
  280. , fusion::vector1<A0> >, Modifiers>
  281. : make_direct_bool<T, Modifiers, Policies> {};
  282. ///////////////////////////////////////////////////////////////////////////
  283. template <typename Modifiers>
  284. struct make_primitive<tag::bool_, Modifiers>
  285. : make_bool<bool, Modifiers> {};
  286. template <typename Modifiers, typename A0>
  287. struct make_primitive<
  288. terminal_ex<tag::bool_
  289. , fusion::vector1<A0> >, Modifiers>
  290. : make_direct_bool<bool, Modifiers> {};
  291. }}}
  292. #endif