ceph/src/boost/libs/spirit/test/lex/dedent_handling_phoenix.cpp

   1 //  Copyright (c) 2009 Carl Barron
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #include <iostream>
   7 #include <sstream>
   8
   9 #include <boost/detail/lightweight_test.hpp>
  10 #include <boost/spirit/include/lex.hpp>
  11 #include <boost/spirit/include/lex_lexertl.hpp>
  12 #include <boost/spirit/include/phoenix.hpp>
  13
  14 namespace lex = boost::spirit::lex;
  15 namespace phoenix = boost::phoenix;
  16
  17 ///////////////////////////////////////////////////////////////////////////////
  18 template <typename Lexer>
  19 struct multi_tokens : lex::lexer<Lexer>
  20 {
  21     int level;
  22
  23     multi_tokens() : level(0)
  24     {
  25         using lex::_state;
  26         using lex::_start;
  27         using lex::_end;
  28         using lex::_pass;
  29         using lex::pass_flags;
  30
  31         a = "A";
  32         b = "B";
  33         c = "C";
  34         this->self =
  35                 a [ ++phoenix::ref(level) ]
  36             |   b
  37             |   c [
  38                       _state = "in_dedenting",
  39                       _end = _start,
  40                       _pass = pass_flags::pass_ignore
  41                   ]
  42             ;
  43
  44         d = ".";
  45         this->self("in_dedenting") =
  46                 d [
  47                       if_(--phoenix::ref(level)) [
  48                           _end = _start
  49                       ]
  50                       .else_ [
  51                           _state = "INITIAL"
  52                       ]
  53                   ]
  54             ;
  55     }
  56
  57     lex::token_def<> a, b, c, d;
  58 };
  59
  60 struct dumper
  61 {
  62     typedef bool result_type;
  63
  64     dumper(std::stringstream& strm) : strm(strm) {}
  65
  66     template <typename Token>
  67     bool operator () (Token const &t)
  68     {
  69         strm << (char)(t.id() - lex::min_token_id + 'a');
  70         return true;
  71     }
  72
  73     std::stringstream& strm;
  74
  75 private:
  76     // silence MSVC warning C4512: assignment operator could not be generated
  77     dumper& operator= (dumper const&);
  78 };
  79
  80 ///////////////////////////////////////////////////////////////////////////////
  81 int main()
  82 {
  83     typedef lex::lexertl::token<std::string::iterator> token_type;
  84     typedef lex::lexertl::actor_lexer<token_type> base_lexer_type;
  85     typedef multi_tokens<base_lexer_type> lexer_type;
  86     typedef lexer_type::iterator_type iterator;
  87
  88     std::string in("AAABBC");
  89     std::string::iterator first(in.begin());
  90     std::stringstream strm;
  91
  92     lexer_type the_lexer;
  93     BOOST_TEST(lex::tokenize(first, in.end(), the_lexer, dumper(strm)));
  94     BOOST_TEST(strm.str() == "aaabbddd");
  95
  96     return boost::report_errors();
  97 }
  98