// Copyright (c) 2001-2010 Hartmut Kaiser // // 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) // The purpose of this example is to show, how it is possible to use a lexer // token definition for two purposes: // // . To generate C++ code implementing a static lexical analyzer allowing // to recognize all defined tokens // . To integrate the generated C++ lexer into the /Spirit/ framework. // // #define BOOST_SPIRIT_LEXERTL_DEBUG #define BOOST_VARIANT_MINIMIZE_SIZE #include #include //[wc_static_include #include //] #include #include #include #include #include #include "../example.hpp" #include "word_count_tokens.hpp" // token definition #include "word_count_static.hpp" // generated tokenizer using namespace boost::spirit; using namespace boost::spirit::ascii; /////////////////////////////////////////////////////////////////////////////// // Grammar definition /////////////////////////////////////////////////////////////////////////////// //[wc_static_grammar // This is an ordinary grammar definition following the rules defined by // Spirit.Qi. There is nothing specific about it, except it gets the token // definition class instance passed to the constructor to allow accessing the // embedded token_def<> instances. template struct word_count_grammar : qi::grammar { template word_count_grammar(TokenDef const& tok) : word_count_grammar::base_type(start) , c(0), w(0), l(0) { using boost::phoenix::ref; using boost::phoenix::size; // associate the defined tokens with the lexer, at the same time // defining the actions to be executed start = *( tok.word [ ++ref(w), ref(c) += size(_1) ] | lit('\n') [ ++ref(l), ++ref(c) ] | qi::token(IDANY) [ ++ref(c) ] ) ; } std::size_t c, w, l; // counter for characters, words, and lines qi::rule start; }; //] /////////////////////////////////////////////////////////////////////////////// //[wc_static_main int main(int argc, char* argv[]) { // Define the token type to be used: 'std::string' is available as the type // of the token value. typedef lex::lexertl::token< char const*, boost::mpl::vector > token_type; // Define the lexer type to be used as the base class for our token // definition. // // This is the only place where the code is different from an equivalent // dynamic lexical analyzer. We use the `lexertl::static_lexer<>` instead of // the `lexertl::lexer<>` as the base class for our token defintion type. // // As we specified the suffix "wc" while generating the static tables we // need to pass the type lexertl::static_::lexer_wc as the second template // parameter below (see word_count_generate.cpp). typedef lex::lexertl::static_lexer< token_type, lex::lexertl::static_::lexer_wc > lexer_type; // Define the iterator type exposed by the lexer. typedef word_count_tokens::iterator_type iterator_type; // Now we use the types defined above to create the lexer and grammar // object instances needed to invoke the parsing process. word_count_tokens word_count; // Our lexer word_count_grammar g (word_count); // Our parser // Read in the file into memory. std::string str (read_from_file(1 == argc ? "word_count.input" : argv[1])); char const* first = str.c_str(); char const* last = &first[str.size()]; // Parsing is done based on the the token stream, not the character stream. bool r = lex::tokenize_and_parse(first, last, word_count, g); if (r) { // success std::cout << "lines: " << g.l << ", words: " << g.w << ", characters: " << g.c << "\n"; } else { std::string rest(first, last); std::cerr << "Parsing failed\n" << "stopped at: \"" << rest << "\"\n"; } return 0; } //]