| /*============================================================================= |
| Copyright (c) 2002-2003 Hartmut Kaiser |
| http://spirit.sourceforge.net/ |
| |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| =============================================================================*/ |
| #ifndef BOOST_SPIRIT_LISTS_HPP |
| #define BOOST_SPIRIT_LISTS_HPP |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| #include <boost/config.hpp> |
| #include <boost/spirit/home/classic/namespace.hpp> |
| #include <boost/spirit/home/classic/meta/as_parser.hpp> |
| #include <boost/spirit/home/classic/core/parser.hpp> |
| #include <boost/spirit/home/classic/core/composite/composite.hpp> |
| |
| #include <boost/spirit/home/classic/utility/lists_fwd.hpp> |
| #include <boost/spirit/home/classic/utility/impl/lists.ipp> |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| namespace boost { namespace spirit { |
| |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // |
| // list_parser class |
| // |
| // List parsers allow to parse constructs like |
| // |
| // item >> *(delim >> item) |
| // |
| // where 'item' is an auxiliary expression to parse and 'delim' is an |
| // auxiliary delimiter to parse. |
| // |
| // The list_parser class also can match an optional closing delimiter |
| // represented by the 'end' parser at the end of the list: |
| // |
| // item >> *(delim >> item) >> !end. |
| // |
| // If ItemT is an action_parser_category type (parser with an attached |
| // semantic action) we have to do something special. This happens, if the |
| // user wrote something like: |
| // |
| // list_p(item[f], delim) |
| // |
| // where 'item' is the parser matching one item of the list sequence and |
| // 'f' is a functor to be called after matching one item. If we would do |
| // nothing, the resulting code would parse the sequence as follows: |
| // |
| // (item[f] - delim) >> *(delim >> (item[f] - delim)) |
| // |
| // what in most cases is not what the user expects. |
| // (If this _is_ what you've expected, then please use one of the list_p |
| // generator functions 'direct()', which will inhibit re-attaching |
| // the actor to the item parser). |
| // |
| // To make the list parser behave as expected: |
| // |
| // (item - delim)[f] >> *(delim >> (item - delim)[f]) |
| // |
| // the actor attached to the 'item' parser has to be re-attached to the |
| // *(item - delim) parser construct, which will make the resulting list |
| // parser 'do the right thing'. |
| // |
| // Additionally special care must be taken, if the item parser is a |
| // unary_parser_category type parser as |
| // |
| // list_p(*anychar_p, ',') |
| // |
| // which without any refactoring would result in |
| // |
| // (*anychar_p - ch_p(',')) |
| // >> *( ch_p(',') >> (*anychar_p - ch_p(',')) ) |
| // |
| // and will not give the expected result (the first *anychar_p will eat up |
| // all the input up to the end of the input stream). So we have to |
| // refactor this into: |
| // |
| // *(anychar_p - ch_p(',')) |
| // >> *( ch_p(',') >> *(anychar_p - ch_p(',')) ) |
| // |
| // what will give the correct result. |
| // |
| // The case, where the item parser is a combination of the two mentioned |
| // problems (i.e. the item parser is a unary parser with an attached |
| // action), is handled accordingly too: |
| // |
| // list_p((*anychar_p)[f], ',') |
| // |
| // will be parsed as expected: |
| // |
| // (*(anychar_p - ch_p(',')))[f] |
| // >> *( ch_p(',') >> (*(anychar_p - ch_p(',')))[f] ). |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| template < |
| typename ItemT, typename DelimT, typename EndT, typename CategoryT |
| > |
| struct list_parser : |
| public parser<list_parser<ItemT, DelimT, EndT, CategoryT> > { |
| |
| typedef list_parser<ItemT, DelimT, EndT, CategoryT> self_t; |
| typedef CategoryT parser_category_t; |
| |
| list_parser(ItemT const &item_, DelimT const &delim_, |
| EndT const& end_ = no_list_endtoken()) |
| : item(item_), delim(delim_), end(end_) |
| {} |
| |
| template <typename ScannerT> |
| typename parser_result<self_t, ScannerT>::type |
| parse(ScannerT const& scan) const |
| { |
| return impl::list_parser_type<CategoryT> |
| ::parse(scan, *this, item, delim, end); |
| } |
| |
| private: |
| typename as_parser<ItemT>::type::embed_t item; |
| typename as_parser<DelimT>::type::embed_t delim; |
| typename as_parser<EndT>::type::embed_t end; |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // |
| // List parser generator template |
| // |
| // This is a helper for generating a correct list_parser<> from |
| // auxiliary parameters. There are the following types supported as |
| // parameters yet: parsers, single characters and strings (see |
| // as_parser<> in meta/as_parser.hpp). |
| // |
| // The list_parser_gen by itself can be used for parsing comma separated |
| // lists without item formatting: |
| // |
| // list_p.parse(...) |
| // matches any comma separated list. |
| // |
| // If list_p is used with one parameter, this parameter is used to match |
| // the delimiter: |
| // |
| // list_p(';').parse(...) |
| // matches any semicolon separated list. |
| // |
| // If list_p is used with two parameters, the first parameter is used to |
| // match the items and the second parameter matches the delimiters: |
| // |
| // list_p(uint_p, ',').parse(...) |
| // matches comma separated unsigned integers. |
| // |
| // If list_p is used with three parameters, the first parameter is used |
| // to match the items, the second one is used to match the delimiters and |
| // the third one is used to match an optional ending token sequence: |
| // |
| // list_p(real_p, ';', eol_p).parse(...) |
| // matches a semicolon separated list of real numbers optionally |
| // followed by an end of line. |
| // |
| // The list_p in the previous examples denotes the predefined parser |
| // generator, which should be used to define list parsers (see below). |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| template <typename CharT = char> |
| struct list_parser_gen : |
| public list_parser<kleene_star<anychar_parser>, chlit<CharT> > |
| { |
| typedef list_parser_gen<CharT> self_t; |
| |
| // construct the list_parser_gen object as an list parser for comma separated |
| // lists without item formatting. |
| list_parser_gen() |
| : list_parser<kleene_star<anychar_parser>, chlit<CharT> > |
| (*anychar_p, chlit<CharT>(',')) |
| {} |
| |
| // The following generator functions should be used under normal circumstances. |
| // (the operator()(...) functions) |
| |
| // Generic generator functions for creation of concrete list parsers, which |
| // support 'normal' syntax: |
| // |
| // item >> *(delim >> item) |
| // |
| // If item isn't given, everything between two delimiters is matched. |
| |
| template<typename DelimT> |
| list_parser< |
| kleene_star<anychar_parser>, |
| typename as_parser<DelimT>::type, |
| no_list_endtoken, |
| unary_parser_category // there is no action to re-attach |
| > |
| operator()(DelimT const &delim_) const |
| { |
| typedef kleene_star<anychar_parser> item_t; |
| typedef typename as_parser<DelimT>::type delim_t; |
| |
| typedef |
| list_parser<item_t, delim_t, no_list_endtoken, unary_parser_category> |
| return_t; |
| |
| return return_t(*anychar_p, as_parser<DelimT>::convert(delim_)); |
| } |
| |
| template<typename ItemT, typename DelimT> |
| list_parser< |
| typename as_parser<ItemT>::type, |
| typename as_parser<DelimT>::type, |
| no_list_endtoken, |
| typename as_parser<ItemT>::type::parser_category_t |
| > |
| operator()(ItemT const &item_, DelimT const &delim_) const |
| { |
| typedef typename as_parser<ItemT>::type item_t; |
| typedef typename as_parser<DelimT>::type delim_t; |
| typedef list_parser<item_t, delim_t, no_list_endtoken, |
| BOOST_DEDUCED_TYPENAME item_t::parser_category_t> |
| return_t; |
| |
| return return_t( |
| as_parser<ItemT>::convert(item_), |
| as_parser<DelimT>::convert(delim_) |
| ); |
| } |
| |
| // Generic generator function for creation of concrete list parsers, which |
| // support 'extended' syntax: |
| // |
| // item >> *(delim >> item) >> !end |
| |
| template<typename ItemT, typename DelimT, typename EndT> |
| list_parser< |
| typename as_parser<ItemT>::type, |
| typename as_parser<DelimT>::type, |
| typename as_parser<EndT>::type, |
| typename as_parser<ItemT>::type::parser_category_t |
| > |
| operator()( |
| ItemT const &item_, DelimT const &delim_, EndT const &end_) const |
| { |
| typedef typename as_parser<ItemT>::type item_t; |
| typedef typename as_parser<DelimT>::type delim_t; |
| typedef typename as_parser<EndT>::type end_t; |
| |
| typedef list_parser<item_t, delim_t, end_t, |
| BOOST_DEDUCED_TYPENAME item_t::parser_category_t> |
| return_t; |
| |
| return return_t( |
| as_parser<ItemT>::convert(item_), |
| as_parser<DelimT>::convert(delim_), |
| as_parser<EndT>::convert(end_) |
| ); |
| } |
| |
| // The following functions should be used, if the 'item' parser has an attached |
| // semantic action or is a unary_parser_category type parser and the structure |
| // of the resulting list parser should _not_ be refactored during parser |
| // construction (see comment above). |
| |
| // Generic generator function for creation of concrete list parsers, which |
| // support 'normal' syntax: |
| // |
| // item >> *(delim >> item) |
| |
| template<typename ItemT, typename DelimT> |
| list_parser< |
| typename as_parser<ItemT>::type, |
| typename as_parser<DelimT>::type, |
| no_list_endtoken, |
| plain_parser_category // inhibit action re-attachment |
| > |
| direct(ItemT const &item_, DelimT const &delim_) const |
| { |
| typedef typename as_parser<ItemT>::type item_t; |
| typedef typename as_parser<DelimT>::type delim_t; |
| typedef list_parser<item_t, delim_t, no_list_endtoken, |
| plain_parser_category> |
| return_t; |
| |
| return return_t( |
| as_parser<ItemT>::convert(item_), |
| as_parser<DelimT>::convert(delim_) |
| ); |
| } |
| |
| // Generic generator function for creation of concrete list parsers, which |
| // support 'extended' syntax: |
| // |
| // item >> *(delim >> item) >> !end |
| |
| template<typename ItemT, typename DelimT, typename EndT> |
| list_parser< |
| typename as_parser<ItemT>::type, |
| typename as_parser<DelimT>::type, |
| typename as_parser<EndT>::type, |
| plain_parser_category // inhibit action re-attachment |
| > |
| direct( |
| ItemT const &item_, DelimT const &delim_, EndT const &end_) const |
| { |
| typedef typename as_parser<ItemT>::type item_t; |
| typedef typename as_parser<DelimT>::type delim_t; |
| typedef typename as_parser<EndT>::type end_t; |
| |
| typedef |
| list_parser<item_t, delim_t, end_t, plain_parser_category> |
| return_t; |
| |
| return return_t( |
| as_parser<ItemT>::convert(item_), |
| as_parser<DelimT>::convert(delim_), |
| as_parser<EndT>::convert(end_) |
| ); |
| } |
| }; |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| // |
| // Predefined list parser generator |
| // |
| // The list_p parser generator can be used |
| // - by itself for parsing comma separated lists without item formatting |
| // or |
| // - for generating list parsers with auxiliary parser parameters |
| // for the 'item', 'delim' and 'end' subsequences. |
| // (see comment above) |
| // |
| /////////////////////////////////////////////////////////////////////////////// |
| const list_parser_gen<> list_p = list_parser_gen<>(); |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_END |
| |
| }} // namespace BOOST_SPIRIT_CLASSIC_NS |
| |
| #endif |