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It is better to manage warnings on our side to know what warnings we need to fix or suppress, and the only thing that header does is disabling deprecation warnings on MSVC and ICC which we would prefer to not show to users.
84 lines
3.2 KiB
C++
84 lines
3.2 KiB
C++
// Copyright (c) 2001-2010 Hartmut Kaiser
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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// The purpose of this example is to show, how it is possible to use a lexer
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// token definition for two purposes:
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//
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// . To generate C++ code implementing a static lexical analyzer allowing
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// to recognize all defined tokens
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// . To integrate the generated C++ lexer into the /Spirit/ framework.
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//
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// #define BOOST_SPIRIT_DEBUG
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// #define BOOST_SPIRIT_LEXERTL_DEBUG
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#include <boost/spirit/include/lex_static_lexertl.hpp>
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#include <iostream>
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#include <string>
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#include "../example.hpp"
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#include "word_count_lexer_tokens.hpp" // token definition
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#include "word_count_lexer_static.hpp" // generated tokenizer
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using namespace boost::spirit;
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///////////////////////////////////////////////////////////////////////////////
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//[wcl_static_main
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int main(int argc, char* argv[])
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{
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// read input from the given file
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std::string str (read_from_file(1 == argc ? "word_count.input" : argv[1]));
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// Specifying 'omit' as the token attribute type generates a token class
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// notholding any token attribute at all (not even the iterator_range of the
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// matched input sequence), therefor optimizing the token, the lexer, and
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// possibly the parser implementation as much as possible.
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//
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// Specifying mpl::false_ as the 3rd template parameter generates a token
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// type and an iterator, both holding no lexer state, allowing for even more
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// aggressive optimizations.
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//
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// As a result the token instances contain the token ids as the only data
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// member.
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typedef lex::lexertl::token<char const*, lex::omit, boost::mpl::false_> token_type;
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// Define the lexer type to be used as the base class for our token
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// definition.
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//
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// This is the only place where the code is different from an equivalent
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// dynamic lexical analyzer. We use the `lexertl::static_lexer<>` instead of
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// the `lexertl::lexer<>` as the base class for our token definition type.
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//
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// As we specified the suffix "wcl" while generating the static tables we
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// need to pass the type lexertl::static_::lexer_wcl as the second template
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// parameter below (see word_count_lexer_generate.cpp).
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typedef lex::lexertl::static_actor_lexer<
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token_type, lex::lexertl::static_::lexer_wcl
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> lexer_type;
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// create the lexer object instance needed to invoke the lexical analysis
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word_count_lexer_tokens<lexer_type> word_count_lexer;
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// tokenize the given string, all generated tokens are discarded
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char const* first = str.c_str();
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char const* last = &first[str.size()];
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bool r = lex::tokenize(first, last, word_count_lexer);
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if (r) {
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std::cout << "lines: " << word_count_lexer.l
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<< ", words: " << word_count_lexer.w
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<< ", characters: " << word_count_lexer.c
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<< "\n";
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}
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else {
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std::string rest(first, last);
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std::cout << "Lexical analysis failed\n" << "stopped at: \""
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<< rest << "\"\n";
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}
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return 0;
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}
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//]
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