Chris@16: // Copyright Vladimir Prus 2002-2004.
Chris@16: // Distributed under the Boost Software License, Version 1.0.
Chris@16: // (See accompanying file LICENSE_1_0.txt
Chris@16: // or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: 
Chris@16: #ifndef BOOST_CONFIG_FILE_VP_2003_01_02
Chris@16: #define BOOST_CONFIG_FILE_VP_2003_01_02
Chris@16: 
Chris@16: #include <iosfwd>
Chris@16: #include <string>
Chris@16: #include <set>
Chris@16: 
Chris@16: #include <boost/noncopyable.hpp>
Chris@16: #include <boost/program_options/config.hpp>
Chris@16: #include <boost/program_options/option.hpp>
Chris@16: #include <boost/program_options/eof_iterator.hpp>
Chris@16: 
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: #include <boost/program_options/detail/convert.hpp>
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042))
Chris@16: #include <istream> // std::getline
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/static_assert.hpp>
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/shared_ptr.hpp>
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: namespace boost { namespace program_options { namespace detail {
Chris@16: 
Chris@16:     /** Standalone parser for config files in ini-line format.
Chris@16:         The parser is a model of single-pass lvalue iterator, and
Chris@16:         default constructor creates past-the-end-iterator. The typical usage is:
Chris@16:         config_file_iterator i(is, ... set of options ...), e;
Chris@16:         for(; i !=e; ++i) {
Chris@16:             *i;
Chris@16:         }
Chris@16:         
Chris@16:         Syntax conventions:
Chris@16: 
Chris@16:         - config file can not contain positional options
Chris@16:         - '#' is comment character: it is ignored together with
Chris@16:           the rest of the line.
Chris@16:         - variable assignments are in the form
Chris@16:           name '=' value.
Chris@16:           spaces around '=' are trimmed.
Chris@16:         - Section names are given in brackets. 
Chris@16: 
Chris@16:          The actual option name is constructed by combining current section
Chris@16:          name and specified option name, with dot between. If section_name 
Chris@16:          already contains dot at the end, new dot is not inserted. For example:
Chris@16:          @verbatim
Chris@16:          [gui.accessibility]
Chris@16:          visual_bell=yes
Chris@16:          @endverbatim
Chris@16:          will result in option "gui.accessibility.visual_bell" with value
Chris@16:          "yes" been returned.
Chris@16: 
Chris@16:          TODO: maybe, we should just accept a pointer to options_description
Chris@16:          class.
Chris@16:      */    
Chris@16:     class common_config_file_iterator 
Chris@16:         : public eof_iterator<common_config_file_iterator, option>
Chris@16:     {
Chris@16:     public:
Chris@16:         common_config_file_iterator() { found_eof(); }
Chris@16:         common_config_file_iterator(
Chris@16:             const std::set<std::string>& allowed_options,
Chris@16:             bool allow_unregistered = false);
Chris@16: 
Chris@16:         virtual ~common_config_file_iterator() {}
Chris@16: 
Chris@16:     public: // Method required by eof_iterator
Chris@16:         
Chris@16:         void get();
Chris@16:         
Chris@16:     protected: // Stubs for derived classes
Chris@16: 
Chris@16:         // Obtains next line from the config file
Chris@16:         // Note: really, this design is a bit ugly
Chris@16:         // The most clean thing would be to pass 'line_iterator' to
Chris@16:         // constructor of this class, but to avoid templating this class
Chris@16:         // we'd need polymorphic iterator, which does not exist yet.
Chris@16:         virtual bool getline(std::string&) { return false; }
Chris@16:         
Chris@16:     private:
Chris@16:         /** Adds another allowed option. If the 'name' ends with
Chris@16:             '*', then all options with the same prefix are
Chris@16:             allowed. For example, if 'name' is 'foo*', then 'foo1' and
Chris@16:             'foo_bar' are allowed. */
Chris@16:         void add_option(const char* name);
Chris@16: 
Chris@16:         // Returns true if 's' is a registered option name.
Chris@16:         bool allowed_option(const std::string& s) const; 
Chris@16: 
Chris@16:         // That's probably too much data for iterator, since
Chris@16:         // it will be copied, but let's not bother for now.
Chris@16:         std::set<std::string> allowed_options;
Chris@16:         // Invariant: no element is prefix of other element.
Chris@16:         std::set<std::string> allowed_prefixes;
Chris@16:         std::string m_prefix;
Chris@16:         bool m_allow_unregistered;
Chris@16:     };
Chris@16: 
Chris@16:     template<class charT>
Chris@16:     class basic_config_file_iterator : public common_config_file_iterator {
Chris@16:     public:
Chris@16:         basic_config_file_iterator()
Chris@16:         {
Chris@16:             found_eof();
Chris@16:         }
Chris@16: 
Chris@16:         /** Creates a config file parser for the specified stream.            
Chris@16:         */
Chris@16:         basic_config_file_iterator(std::basic_istream<charT>& is, 
Chris@16:                                    const std::set<std::string>& allowed_options,
Chris@16:                                    bool allow_unregistered = false); 
Chris@16: 
Chris@16:     private: // base overrides
Chris@16: 
Chris@16:         bool getline(std::string&);
Chris@16: 
Chris@16:     private: // internal data
Chris@16:         shared_ptr<std::basic_istream<charT> > is;
Chris@16:     };
Chris@16:     
Chris@16:     typedef basic_config_file_iterator<char> config_file_iterator;
Chris@16:     typedef basic_config_file_iterator<wchar_t> wconfig_file_iterator;
Chris@16: 
Chris@16: 
Chris@16:     struct null_deleter
Chris@16:     {
Chris@16:         void operator()(void const *) const {}
Chris@16:     };
Chris@16: 
Chris@16: 
Chris@16:     template<class charT>
Chris@16:     basic_config_file_iterator<charT>::
Chris@16:     basic_config_file_iterator(std::basic_istream<charT>& is, 
Chris@16:                                const std::set<std::string>& allowed_options,
Chris@16:                                bool allow_unregistered)
Chris@16:     : common_config_file_iterator(allowed_options, allow_unregistered)
Chris@16:     {
Chris@16:         this->is.reset(&is, null_deleter());                 
Chris@16:         get();
Chris@16:     }
Chris@16: 
Chris@16:     // Specializing this function for wchar_t causes problems on
Chris@16:     // borland and vc7, as well as on metrowerks. On the first two
Chris@16:     // I don't know a workaround, so make use of 'to_internal' to
Chris@16:     // avoid specialization.
Chris@16:     template<class charT>
Chris@16:     bool
Chris@16:     basic_config_file_iterator<charT>::getline(std::string& s)
Chris@16:     {
Chris@16:         std::basic_string<charT> in;
Chris@16:         if (std::getline(*is, in)) {
Chris@16:             s = to_internal(in);
Chris@16:             return true;
Chris@16:         } else {
Chris@16:             return false;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     // Specialization is needed to workaround getline bug on Comeau.
Chris@16: #if BOOST_WORKAROUND(__COMO_VERSION__, BOOST_TESTED_AT(4303)) || \
Chris@16:         (defined(__sgi) && BOOST_WORKAROUND(_COMPILER_VERSION, BOOST_TESTED_AT(741)))
Chris@16:     template<>
Chris@16:     bool
Chris@16:     basic_config_file_iterator<wchar_t>::getline(std::string& s);
Chris@16: #endif
Chris@16: 
Chris@16:     
Chris@16: 
Chris@16: }}}
Chris@16: 
Chris@16: #endif