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_core.hpp>
  13 #include <boost/spirit/include/phoenix_operator.hpp>
  14 #include <boost/spirit/include/phoenix_statement.hpp>
  15
  16 namespace lex = boost::spirit::lex;
  17 namespace phoenix = boost::phoenix;
  18
  19 ///////////////////////////////////////////////////////////////////////////////
  20 template <typename Lexer>
  21 struct multi_tokens : lex::lexer<Lexer>
  22 {
  23     int level;
  24
  25     multi_tokens() : level(0)
  26     {
  27         using lex::_state;
  28         using lex::_start;
  29         using lex::_end;
  30         using lex::_pass;
  31         using lex::pass_flags;
  32
  33         a = "A";
  34         b = "B";
  35         c = "C";
  36         this->self =
  37                 a [ ++phoenix::ref(level) ]
  38             |   b
  39             |   c [(
  40                       _state = "in_dedenting",
  41                       _end = _start,
  42                       _pass = pass_flags::pass_ignore
  43                   )]
  44             ;
  45
  46         d = ".";
  47         this->self("in_dedenting") =
  48                 d [
  49                       if_(--phoenix::ref(level)) [
  50                           _end = _start
  51                       ]
  52                       .else_ [
  53                           _state = "INITIAL"
  54                       ]
  55                   ]
  56             ;
  57     }
  58
  59     lex::token_def<> a, b, c, d;
  60 };
  61
  62 struct dumper
  63 {
  64     typedef bool result_type;
  65
  66     dumper(std::stringstream& strm) : strm(strm) {}
  67
  68     template <typename Token>
  69     bool operator () (Token const &t)
  70     {
  71         strm << (char)(t.id() - lex::min_token_id + 'a');
  72         return true;
  73     }
  74
  75     std::stringstream& strm;
  76
  77     // silence MSVC warning C4512: assignment operator could not be generated
  78     BOOST_DELETED_FUNCTION(dumper& operator= (dumper const&));
  79 };
  80
  81 ///////////////////////////////////////////////////////////////////////////////
  82 int main()
  83 {
  84     typedef lex::lexertl::token<std::string::iterator> token_type;
  85     typedef lex::lexertl::actor_lexer<token_type> base_lexer_type;
  86     typedef multi_tokens<base_lexer_type> lexer_type;
  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