ceph/src/boost/libs/spirit/example/x3/calc/calc7/main.cpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2014 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 ///////////////////////////////////////////////////////////////////////////////
   8 //
   9 //  Same as calc6, but this version also shows off grammar modularization.
  10 //  Here you will see how expressions is built as a modular grammars.
  11 //
  12 //  [ JDG Sometime 2000 ]       pre-boost
  13 //  [ JDG September 18, 2002 ]  spirit1
  14 //  [ JDG April 8, 2007 ]       spirit2
  15 //  [ JDG February 18, 2011 ]   Pure attributes. No semantic actions.
  16 //  [ JDG April 9, 2014 ]       Spirit X3 (from qi calc6)
  17 //  [ JDG May 2, 2014 ]         Modular grammar using BOOST_SPIRIT_DEFINE.
  18 //
  19 ///////////////////////////////////////////////////////////////////////////////
  20
  21 #include "ast.hpp"
  22 #include "vm.hpp"
  23 #include "compiler.hpp"
  24 #include "expression.hpp"
  25 #include "error_handler.hpp"
  26
  27 ///////////////////////////////////////////////////////////////////////////////
  28 //  Main program
  29 ///////////////////////////////////////////////////////////////////////////////
  30 int
  31 main()
  32 {
  33     std::cout << "/////////////////////////////////////////////////////////\n\n";
  34     std::cout << "Expression parser...\n\n";
  35     std::cout << "/////////////////////////////////////////////////////////\n\n";
  36     std::cout << "Type an expression...or [q or Q] to quit\n\n";
  37
  38     typedef std::string::const_iterator iterator_type;
  39     typedef client::ast::expression ast_expression;
  40     typedef client::compiler compiler;
  41
  42     std::string str;
  43     while (std::getline(std::cin, str))
  44     {
  45         if (str.empty() || str[0] == 'q' || str[0] == 'Q')
  46             break;
  47
  48         using boost::spirit::x3::ascii::space;
  49
  50         client::vmachine mach;                          // Our virtual machine
  51         std::vector<int> code;                          // Our VM code
  52         auto calc = client::expression();               // grammar
  53
  54         ast_expression ast;                             // Our program (AST)
  55         compiler compile(code);                         // Compiles the program
  56
  57         iterator_type iter = str.begin();
  58         iterator_type const end = str.end();
  59         bool r = phrase_parse(iter, end, calc, space, ast);
  60
  61         if (r && iter == end)
  62         {
  63             std::cout << "-------------------------\n";
  64             std::cout << "Parsing succeeded\n";
  65             compile(ast);
  66             mach.execute(code);
  67             std::cout << "\nResult: " << mach.top() << std::endl;
  68             std::cout << "-------------------------\n";
  69         }
  70         else
  71         {
  72             std::string rest(iter, end);
  73             std::cout << "-------------------------\n";
  74             std::cout << "Parsing failed\n";
  75             std::cout << "-------------------------\n";
  76         }
  77     }
  78
  79     std::cout << "Bye... :-) \n\n";
  80     return 0;
  81 }