ceph/src/boost/libs/spirit/example/qi/compiler_tutorial/calc8/error_handler.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 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 #if !defined(BOOST_SPIRIT_CALC8_ERROR_HANDLER_HPP)
   8 #define BOOST_SPIRIT_CALC8_ERROR_HANDLER_HPP
   9
  10 #include <iostream>
  11 #include <string>
  12 #include <vector>
  13
  14 namespace client
  15 {
  16     ///////////////////////////////////////////////////////////////////////////////
  17     //  The error handler
  18     ///////////////////////////////////////////////////////////////////////////////
  19     template <typename Iterator>
  20     struct error_handler
  21     {
  22         template <typename, typename, typename>
  23         struct result { typedef void type; };
  24
  25         error_handler(Iterator first, Iterator last)
  26           : first(first), last(last) {}
  27
  28         template <typename Message, typename What>
  29         void operator()(
  30             Message const& message,
  31             What const& what,
  32             Iterator err_pos) const
  33         {
  34             int line;
  35             Iterator line_start = get_pos(err_pos, line);
  36             if (err_pos != last)
  37             {
  38                 std::cout << message << what << " line " << line << ':' << std::endl;
  39                 std::cout << get_line(line_start) << std::endl;
  40                 for (; line_start != err_pos; ++line_start)
  41                     std::cout << ' ';
  42                 std::cout << '^' << std::endl;
  43             }
  44             else
  45             {
  46                 std::cout << "Unexpected end of file. ";
  47                 std::cout << message << what << " line " << line << std::endl;
  48             }
  49         }
  50
  51         Iterator get_pos(Iterator err_pos, int& line) const
  52         {
  53             line = 1;
  54             Iterator i = first;
  55             Iterator line_start = first;
  56             while (i != err_pos)
  57             {
  58                 bool eol = false;
  59                 if (i != err_pos && *i == '\r') // CR
  60                 {
  61                     eol = true;
  62                     line_start = ++i;
  63                 }
  64                 if (i != err_pos && *i == '\n') // LF
  65                 {
  66                     eol = true;
  67                     line_start = ++i;
  68                 }
  69                 if (eol)
  70                     ++line;
  71                 else
  72                     ++i;
  73             }
  74             return line_start;
  75         }
  76
  77         std::string get_line(Iterator err_pos) const
  78         {
  79             Iterator i = err_pos;
  80             // position i to the next EOL
  81             while (i != last && (*i != '\r' && *i != '\n'))
  82                 ++i;
  83             return std::string(err_pos, i);
  84         }
  85
  86         Iterator first;
  87         Iterator last;
  88         std::vector<Iterator> iters;
  89     };
  90 }
  91
  92 #endif
  93