boost/spirit/repository/home/qi/nonterminal/subrule.hpp

   1 /*=============================================================================
   2     Copyright (c) 2009 Francois Barel
   3     Copyright (c) 2001-2011 Joel de Guzman
   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_REPOSITORY_QI_SUBRULE_AUGUST_06_2009_0239AM)
   9 #define BOOST_SPIRIT_REPOSITORY_QI_SUBRULE_AUGUST_06_2009_0239AM
  10
  11 #if defined(_MSC_VER)
  12 #pragma once
  13 #endif
  14
  15 #include <boost/spirit/home/qi/domain.hpp>
  16 #include <boost/spirit/home/qi/meta_compiler.hpp>
  17 #include <boost/spirit/home/qi/parser.hpp>
  18 #include <boost/spirit/home/qi/reference.hpp>
  19 #include <boost/spirit/home/qi/nonterminal/detail/parameterized.hpp>
  20 #include <boost/spirit/home/qi/nonterminal/detail/parser_binder.hpp>
  21 #include <boost/spirit/home/support/argument.hpp>
  22 #include <boost/spirit/home/support/assert_msg.hpp>
  23 #include <boost/spirit/home/qi/detail/attributes.hpp>
  24 #include <boost/spirit/home/support/info.hpp>
  25 #include <boost/spirit/home/support/unused.hpp>
  26 #include <boost/spirit/home/support/nonterminal/extract_param.hpp>
  27 #include <boost/spirit/home/support/nonterminal/locals.hpp>
  28 #include <boost/spirit/repository/home/support/subrule_context.hpp>
  29
  30 #include <boost/fusion/include/as_map.hpp>
  31 #include <boost/fusion/include/at_key.hpp>
  32 #include <boost/fusion/include/cons.hpp>
  33 #include <boost/fusion/include/front.hpp>
  34 #include <boost/fusion/include/has_key.hpp>
  35 #include <boost/fusion/include/join.hpp>
  36 #include <boost/fusion/include/make_map.hpp>
  37 #include <boost/fusion/include/make_vector.hpp>
  38 #include <boost/fusion/include/size.hpp>
  39 #include <boost/fusion/include/vector.hpp>
  40 #include <boost/mpl/bool.hpp>
  41 #include <boost/mpl/identity.hpp>
  42 #include <boost/mpl/int.hpp>
  43 #include <boost/mpl/vector.hpp>
  44 #include <boost/type_traits/add_reference.hpp>
  45 #include <boost/type_traits/is_same.hpp>
  46 #include <boost/type_traits/remove_reference.hpp>
  47
  48 #if defined(BOOST_MSVC)
  49 # pragma warning(push)
  50 # pragma warning(disable: 4355) // 'this' : used in base member initializer list warning
  51 #endif
  52
  53 ///////////////////////////////////////////////////////////////////////////////
  54 namespace boost { namespace spirit { namespace repository { namespace qi
  55 {
  56     ///////////////////////////////////////////////////////////////////////////
  57     // subrule_group:
  58     // - parser representing a group of subrule definitions (one or more),
  59     //   invokes first subrule on entry,
  60     // - also a Proto terminal, so that a group behaves like any Spirit
  61     //   expression.
  62     ///////////////////////////////////////////////////////////////////////////
  63     template <typename Defs>
  64     struct subrule_group
  65       : proto::extends<
  66             typename proto::terminal<
  67                 spirit::qi::reference<subrule_group<Defs> const>
  68             >::type
  69           , subrule_group<Defs>
  70         >
  71       , spirit::qi::parser<subrule_group<Defs> >
  72     {
  73         // Fusion associative sequence, associating each subrule ID in this
  74         // group (as an MPL integral constant) with its definition
  75         typedef Defs defs_type;
  76
  77         typedef subrule_group<Defs> this_type;
  78         typedef spirit::qi::reference<this_type const> reference_;
  79         typedef typename proto::terminal<reference_>::type terminal;
  80         typedef proto::extends<terminal, this_type> base_type;
  81
  82         static size_t const params_size =
  83             // Forward to first subrule.
  84             remove_reference<
  85                 typename fusion::result_of::front<Defs>::type
  86             >::type::second_type::params_size;
  87
  88         subrule_group(subrule_group const& rhs)
  89           : base_type(terminal::make(reference_(*this)))
  90           , defs(rhs.defs)
  91         {
  92         }
  93
  94         explicit subrule_group(Defs const& defs)
  95           : base_type(terminal::make(reference_(*this)))
  96           , defs(defs)
  97         {
  98         }
  99
 100         // from a subrule ID, get the type of a reference to its definition
 101         template <int ID>
 102         struct def_type
 103         {
 104             typedef mpl::int_<ID> id_type;
 105
 106             // If you are seeing a compilation error here, you are trying
 107             // to use a subrule which was not defined in this group.
 108             BOOST_SPIRIT_ASSERT_MSG(
 109                 (fusion::result_of::has_key<
 110                     defs_type const, id_type>::type::value)
 111               , subrule_used_without_being_defined, (mpl::int_<ID>));
 112
 113             typedef typename
 114                 fusion::result_of::at_key<defs_type const, id_type>::type
 115             type;
 116         };
 117
 118         // from a subrule ID, get a reference to its definition
 119         template <int ID>
 120         typename def_type<ID>::type def() const
 121         {
 122             return fusion::at_key<mpl::int_<ID> >(defs);
 123         }
 124
 125         template <typename Context, typename Iterator>
 126         struct attribute
 127             // Forward to first subrule.
 128           : mpl::identity<
 129                 typename remove_reference<
 130                     typename fusion::result_of::front<Defs>::type
 131                 >::type::second_type::attr_type> {};
 132
 133         template <typename Iterator, typename Context
 134           , typename Skipper, typename Attribute>
 135         bool parse(Iterator& first, Iterator const& last
 136           , Context& context, Skipper const& skipper
 137           , Attribute& attr) const
 138         {
 139             // Forward to first subrule.
 140             return parse_subrule(fusion::front(defs).second
 141               , first, last, context, skipper, attr);
 142         }
 143
 144         template <typename Iterator, typename Context
 145           , typename Skipper, typename Attribute, typename Params>
 146         bool parse(Iterator& first, Iterator const& last
 147           , Context& context, Skipper const& skipper
 148           , Attribute& attr, Params const& params) const
 149         {
 150             // Forward to first subrule.
 151             return parse_subrule(fusion::front(defs).second
 152               , first, last, context, skipper, attr, params);
 153         }
 154
 155         template <int ID, typename Iterator, typename Context
 156           , typename Skipper, typename Attribute>
 157         bool parse_subrule_id(Iterator& first, Iterator const& last
 158           , Context& context, Skipper const& skipper
 159           , Attribute& attr) const
 160         {
 161             return parse_subrule(def<ID>()
 162               , first, last, context, skipper, attr);
 163         }
 164
 165         template <int ID, typename Iterator, typename Context
 166           , typename Skipper, typename Attribute, typename Params>
 167         bool parse_subrule_id(Iterator& first, Iterator const& last
 168           , Context& context, Skipper const& skipper
 169           , Attribute& attr, Params const& params) const
 170         {
 171             return parse_subrule(def<ID>()
 172               , first, last, context, skipper, attr, params);
 173         }
 174
 175         template <typename Def
 176           , typename Iterator, typename Context
 177           , typename Skipper, typename Attribute>
 178         bool parse_subrule(Def const& def
 179           , Iterator& first, Iterator const& last
 180           , Context& /*caller_context*/, Skipper const& skipper
 181           , Attribute& attr) const
 182         {
 183             // compute context type for this subrule
 184             typedef typename Def::locals_type subrule_locals_type;
 185             typedef typename Def::attr_type subrule_attr_type;
 186             typedef typename Def::attr_reference_type subrule_attr_reference_type;
 187             typedef typename Def::parameter_types subrule_parameter_types;
 188
 189             typedef
 190                 subrule_context<
 191                     this_type
 192                   , fusion::cons<
 193                         subrule_attr_reference_type, subrule_parameter_types>
 194                   , subrule_locals_type
 195                 >
 196             context_type;
 197
 198             // prepare attribute
 199             typedef traits::make_attribute<
 200                 subrule_attr_type, Attribute> make_attribute;
 201
 202             // do down-stream transformation, provides attribute for
 203             // rhs parser
 204             typedef traits::transform_attribute<
 205                 typename make_attribute::type, subrule_attr_type, spirit::qi::domain>
 206             transform;
 207
 208             typename make_attribute::type made_attr = make_attribute::call(attr);
 209             typename transform::type attr_ = transform::pre(made_attr);
 210
 211             // If you are seeing a compilation error here, you are probably
 212             // trying to use a subrule which has inherited attributes,
 213             // without passing values for them.
 214             context_type context(*this, attr_);
 215
 216             if (def.binder(first, last, context, skipper))
 217             {
 218                 // do up-stream transformation, this integrates the results
 219                 // back into the original attribute value, if appropriate
 220                 traits::post_transform(attr, attr_);
 221                 return true;
 222             }
 223
 224             // inform attribute transformation of failed rhs
 225             traits::fail_transform(attr, attr_);
 226             return false;
 227         }
 228
 229         template <typename Def
 230           , typename Iterator, typename Context
 231           , typename Skipper, typename Attribute, typename Params>
 232         bool parse_subrule(Def const& def
 233           , Iterator& first, Iterator const& last
 234           , Context& caller_context, Skipper const& skipper
 235           , Attribute& attr, Params const& params) const
 236         {
 237             // compute context type for this subrule
 238             typedef typename Def::locals_type subrule_locals_type;
 239             typedef typename Def::attr_type subrule_attr_type;
 240             typedef typename Def::attr_reference_type subrule_attr_reference_type;
 241             typedef typename Def::parameter_types subrule_parameter_types;
 242
 243             typedef
 244                 subrule_context<
 245                     this_type
 246                   , fusion::cons<
 247                         subrule_attr_reference_type, subrule_parameter_types>
 248                   , subrule_locals_type
 249                 >
 250             context_type;
 251
 252             // prepare attribute
 253             typedef traits::make_attribute<
 254                 subrule_attr_type, Attribute> make_attribute;
 255
 256             // do down-stream transformation, provides attribute for
 257             // rhs parser
 258             typedef traits::transform_attribute<
 259                 typename make_attribute::type, subrule_attr_type, spirit::qi::domain>
 260             transform;
 261
 262             typename make_attribute::type made_attr = make_attribute::call(attr);
 263             typename transform::type attr_ = transform::pre(made_attr);
 264
 265             // If you are seeing a compilation error here, you are probably
 266             // trying to use a subrule which has inherited attributes,
 267             // passing values of incompatible types for them.
 268             context_type context(*this, attr_, params, caller_context);
 269
 270             if (def.binder(first, last, context, skipper))
 271             {
 272                 // do up-stream transformation, this integrates the results
 273                 // back into the original attribute value, if appropriate
 274                 traits::post_transform(attr, attr_);
 275                 return true;
 276             }
 277
 278             // inform attribute transformation of failed rhs
 279             traits::fail_transform(attr, attr_);
 280             return false;
 281         }
 282
 283         template <typename Context>
 284         info what(Context& context) const
 285         {
 286             // Forward to first subrule.
 287             return fusion::front(defs).second.binder.p.what(context);
 288         }
 289
 290         template <typename Defs2>
 291         subrule_group<
 292             typename fusion::result_of::as_map<
 293                 typename fusion::result_of::join<
 294                     Defs const, Defs2 const>::type>::type>
 295         operator,(subrule_group<Defs2> const& other) const
 296         {
 297             typedef subrule_group<
 298                 typename fusion::result_of::as_map<
 299                     typename fusion::result_of::join<
 300                         Defs const, Defs2 const>::type>::type> result_type;
 301             return result_type(fusion::as_map(fusion::join(defs, other.defs)));
 302         }
 303
 304         // bring in the operator() overloads
 305         this_type const& get_parameterized_subject() const { return *this; }
 306         typedef this_type parameterized_subject_type;
 307         #include <boost/spirit/home/qi/nonterminal/detail/fcall.hpp>
 308
 309         Defs defs;
 310     };
 311
 312     ///////////////////////////////////////////////////////////////////////////
 313     // subrule_definition: holds one particular definition of a subrule
 314     ///////////////////////////////////////////////////////////////////////////
 315     template <
 316         int ID_
 317       , typename Locals
 318       , typename Attr
 319       , typename AttrRef
 320       , typename Parameters
 321       , size_t ParamsSize
 322       , typename Subject
 323       , bool Auto_
 324     >
 325     struct subrule_definition
 326     {
 327         typedef mpl::int_<ID_> id_type;
 328         BOOST_STATIC_CONSTANT(int, ID = ID_);
 329
 330         typedef Locals locals_type;
 331         typedef Attr attr_type;
 332         typedef AttrRef attr_reference_type;
 333         typedef Parameters parameter_types;
 334         static size_t const params_size = ParamsSize;
 335
 336         typedef Subject subject_type;
 337         typedef mpl::bool_<Auto_> auto_type;
 338         BOOST_STATIC_CONSTANT(bool, Auto = Auto_);
 339
 340         typedef spirit::qi::detail::parser_binder<
 341             Subject, auto_type> binder_type;
 342
 343         subrule_definition(Subject const& subject, std::string const& name)
 344           : binder(subject), name(name)
 345         {
 346         }
 347
 348         binder_type const binder;
 349         std::string const name;
 350     };
 351
 352     ///////////////////////////////////////////////////////////////////////////
 353     // subrule placeholder:
 354     // - on subrule definition: helper for creation of subrule_group,
 355     // - on subrule invocation: Proto terminal and parser.
 356     ///////////////////////////////////////////////////////////////////////////
 357     template <
 358         int ID_
 359       , typename T1 = unused_type
 360       , typename T2 = unused_type
 361     >
 362     struct subrule
 363       : proto::extends<
 364             typename proto::terminal<
 365                 spirit::qi::reference<subrule<ID_, T1, T2> const>
 366             >::type
 367           , subrule<ID_, T1, T2>
 368         >
 369       , spirit::qi::parser<subrule<ID_, T1, T2> >
 370     {
 371         typedef mpl::int_<ID_> id_type;
 372         BOOST_STATIC_CONSTANT(int, ID = ID_);
 373
 374         typedef subrule<ID_, T1, T2> this_type;
 375         typedef spirit::qi::reference<this_type const> reference_;
 376         typedef typename proto::terminal<reference_>::type terminal;
 377         typedef proto::extends<terminal, this_type> base_type;
 378
 379         typedef mpl::vector<T1, T2> template_params;
 380
 381         // locals_type is a sequence of types to be used as local variables
 382         typedef typename
 383             spirit::detail::extract_locals<template_params>::type
 384         locals_type;
 385
 386         typedef typename
 387             spirit::detail::extract_sig<template_params>::type
 388         sig_type;
 389
 390         // This is the subrule's attribute type
 391         typedef typename
 392             spirit::detail::attr_from_sig<sig_type>::type
 393         attr_type;
 394         typedef typename add_reference<attr_type>::type attr_reference_type;
 395
 396         // parameter_types is a sequence of types passed as parameters to the subrule
 397         typedef typename
 398             spirit::detail::params_from_sig<sig_type>::type
 399         parameter_types;
 400
 401         static size_t const params_size =
 402             fusion::result_of::size<parameter_types>::type::value;
 403
 404         explicit subrule(std::string const& name_ = "unnamed-subrule")
 405           : base_type(terminal::make(reference_(*this)))
 406           , name_(name_)
 407         {
 408         }
 409
 410         // compute type of this subrule's definition for expr type Expr
 411         template <typename Expr, bool Auto>
 412         struct def_type_helper
 413         {
 414             // Report invalid expression error as early as possible.
 415             // If you got an error_invalid_expression error message here,
 416             // then the expression (Expr) is not a valid spirit qi expression.
 417             BOOST_SPIRIT_ASSERT_MATCH(spirit::qi::domain, Expr);
 418
 419             typedef typename result_of::compile<
 420                 spirit::qi::domain, Expr>::type subject_type;
 421
 422             typedef subrule_definition<
 423                 ID_
 424               , locals_type
 425               , attr_type
 426               , attr_reference_type
 427               , parameter_types
 428               , params_size
 429               , subject_type
 430               , Auto
 431             > const type;
 432         };
 433
 434         // compute type of subrule group containing only this
 435         // subrule's definition for expr type Expr
 436         template <typename Expr, bool Auto>
 437         struct group_type_helper
 438         {
 439             typedef typename def_type_helper<Expr, Auto>::type def_type;
 440
 441             // create Defs map with only one entry: (ID -> def)
 442             typedef typename
 443                 fusion::result_of::make_map<id_type, def_type>::type
 444             defs_type;
 445
 446             typedef subrule_group<defs_type> type;
 447         };
 448
 449         template <typename Expr>
 450         typename group_type_helper<Expr, false>::type
 451         operator=(Expr const& expr) const
 452         {
 453             typedef group_type_helper<Expr, false> helper;
 454             typedef typename helper::def_type def_type;
 455             typedef typename helper::type result_type;
 456             return result_type(fusion::make_map<id_type>(
 457                 def_type(compile<spirit::qi::domain>(expr), name_)));
 458         }
 459
 460         template <typename Expr>
 461         friend typename group_type_helper<Expr, true>::type
 462         operator%=(subrule const& sr, Expr const& expr)
 463         {
 464             typedef group_type_helper<Expr, true> helper;
 465             typedef typename helper::def_type def_type;
 466             typedef typename helper::type result_type;
 467             return result_type(fusion::make_map<id_type>(
 468                 def_type(compile<spirit::qi::domain>(expr), sr.name_)));
 469         }
 470
 471         // non-const versions needed to suppress proto's %= kicking in
 472         template <typename Expr>
 473         friend typename group_type_helper<Expr, true>::type
 474         operator%=(subrule const& sr, Expr& expr)
 475         {
 476             return operator%=(
 477                 sr
 478               , static_cast<Expr const&>(expr));
 479         }
 480         template <typename Expr>
 481         friend typename group_type_helper<Expr, true>::type
 482         operator%=(subrule& sr, Expr const& expr)
 483         {
 484             return operator%=(
 485                 static_cast<subrule const&>(sr)
 486               , expr);
 487         }
 488         template <typename Expr>
 489         friend typename group_type_helper<Expr, true>::type
 490         operator%=(subrule& sr, Expr& expr)
 491         {
 492             return operator%=(
 493                 static_cast<subrule const&>(sr)
 494               , static_cast<Expr const&>(expr));
 495         }
 496
 497         std::string const& name() const
 498         {
 499             return name_;
 500         }
 501
 502         void name(std::string const& str)
 503         {
 504             name_ = str;
 505         }
 506
 507         template <typename Context, typename Iterator>
 508         struct attribute
 509         {
 510             typedef attr_type type;
 511         };
 512
 513         template <typename Iterator, typename Group
 514           , typename Attributes, typename Locals
 515           , typename Skipper, typename Attribute>
 516         bool parse(Iterator& first, Iterator const& last
 517           , subrule_context<Group, Attributes, Locals>& context
 518           , Skipper const& skipper, Attribute& attr) const
 519         {
 520             return context.group.template parse_subrule_id<ID_>(
 521                 first, last, context, skipper, attr);
 522         }
 523
 524         template <typename Iterator, typename Context
 525           , typename Skipper, typename Attribute>
 526         bool parse(Iterator& /*first*/, Iterator const& /*last*/
 527           , Context& /*context*/
 528           , Skipper const& /*skipper*/, Attribute& /*attr*/) const
 529         {
 530             // If you are seeing a compilation error here, you are trying
 531             // to use a subrule as a parser outside of a subrule group.
 532             BOOST_SPIRIT_ASSERT_FAIL(Iterator
 533               , subrule_used_outside_subrule_group, (id_type));
 534
 535             return false;
 536         }
 537
 538         template <typename Iterator, typename Group
 539           , typename Attributes, typename Locals
 540           , typename Skipper, typename Attribute
 541           , typename Params>
 542         bool parse(Iterator& first, Iterator const& last
 543           , subrule_context<Group, Attributes, Locals>& context
 544           , Skipper const& skipper, Attribute& attr
 545           , Params const& params) const
 546         {
 547             return context.group.template parse_subrule_id<ID_>(
 548                 first, last, context, skipper, attr, params);
 549         }
 550
 551         template <typename Iterator, typename Context
 552           , typename Skipper, typename Attribute
 553           , typename Params>
 554         bool parse(Iterator& /*first*/, Iterator const& /*last*/
 555           , Context& /*context*/
 556           , Skipper const& /*skipper*/, Attribute& /*attr*/
 557           , Params const& /*params*/) const
 558         {
 559             // If you are seeing a compilation error here, you are trying
 560             // to use a subrule as a parser outside of a subrule group.
 561             BOOST_SPIRIT_ASSERT_FAIL(Iterator
 562               , subrule_used_outside_subrule_group, (id_type));
 563
 564             return false;
 565         }
 566
 567         template <typename Context>
 568         info what(Context& /*context*/) const
 569         {
 570             return info(name_);
 571         }
 572
 573         // bring in the operator() overloads
 574         this_type const& get_parameterized_subject() const { return *this; }
 575         typedef this_type parameterized_subject_type;
 576         #include <boost/spirit/home/qi/nonterminal/detail/fcall.hpp>
 577
 578         std::string name_;
 579     };
 580 }}}}
 581
 582 #if defined(BOOST_MSVC)
 583 # pragma warning(pop)
 584 #endif
 585
 586 #endif