ceph/src/boost/libs/wave/include/boost/wave/cpplexer/convert_trigraphs.hpp

   1 /*=============================================================================
   2     Boost.Wave: A Standard compliant C++ preprocessor library
   3
   4     Grammar for universal character validation (see C++ standard: Annex E)
   5
   6     http://www.boost.org/
   7
   8     Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
   9     Software License, Version 1.0. (See accompanying file
  10     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  11 =============================================================================*/
  12 #if !defined(CONVERT_TRIGRAPHS_HK050403_INCLUDED)
  13 #define CONVERT_TRIGRAPHS_HK050403_INCLUDED
  14
  15 #include <boost/wave/wave_config.hpp>
  16 #include <boost/wave/cpplexer/cpplexer_exceptions.hpp>
  17
  18 // this must occur after all of the includes and before any code appears
  19 #ifdef BOOST_HAS_ABI_HEADERS
  20 #include BOOST_ABI_PREFIX
  21 #endif
  22
  23 ///////////////////////////////////////////////////////////////////////////////
  24 namespace boost {
  25 namespace wave {
  26 namespace cpplexer {
  27 namespace impl {
  28
  29 ///////////////////////////////////////////////////////////////////////////////
  30 //
  31 //  Test, whether the given string represents a valid trigraph sequence
  32 //
  33 ///////////////////////////////////////////////////////////////////////////////
  34 template <typename StringT>
  35 inline bool
  36 is_trigraph(StringT const& trigraph)
  37 {
  38     if (trigraph.size() < 3 || '?' != trigraph[0] || '?' != trigraph[1])
  39         return false;
  40
  41     switch (trigraph[2]) {
  42     case '\'': case '=': case '/': case '(':
  43     case ')':  case '<': case '>': case '!':
  44     case '-':
  45         break;
  46
  47     default:
  48         return false;
  49     }
  50
  51     return true;
  52 }
  53
  54 ///////////////////////////////////////////////////////////////////////////////
  55 //
  56 //  convert_trigraph
  57 //
  58 //    The function convert_trigraph() converts a single trigraph character
  59 //    sequence into the corresponding character.
  60 //
  61 //    If the given character sequence doesn't form a valid trigraph sequence
  62 //    no conversion is performed.
  63 //
  64 ///////////////////////////////////////////////////////////////////////////////
  65 template <typename StringT>
  66 inline StringT
  67 convert_trigraph(StringT const &trigraph)
  68 {
  69 StringT result (trigraph);
  70
  71     if (is_trigraph(trigraph)) {
  72         switch (trigraph[2]) {
  73         case '\'':  result = "^"; break;
  74         case '=':   result = "#"; break;
  75         case '/':   result = "\\"; break;
  76         case '(':   result = "["; break;
  77         case ')':   result = "]"; break;
  78         case '<':   result = "{"; break;
  79         case '>':   result = "}"; break;
  80         case '!':   result = "|"; break;
  81         case '-':   result = "~"; break;
  82         }
  83     }
  84     return result;
  85 }
  86
  87 ///////////////////////////////////////////////////////////////////////////////
  88 //
  89 //  convert_trigraphs
  90 //
  91 //    The function convert_trigraph() converts all trigraphs in the given
  92 //    string into the corresponding characters.
  93 //
  94 //    If one of the given character sequences doesn't form a valid trigraph
  95 //    sequence no conversion is performed.
  96 //
  97 ///////////////////////////////////////////////////////////////////////////////
  98 template <typename StringT>
  99 inline StringT
 100 convert_trigraphs(StringT const &value)
 101 {
 102     StringT result;
 103     typename StringT::size_type pos = 0;
 104     typename StringT::size_type pos1 = value.find_first_of ("?", 0);
 105     if (StringT::npos != pos1) {
 106         do {
 107             result += value.substr(pos, pos1-pos);
 108             StringT trigraph (value.substr(pos1));
 109             if (is_trigraph(trigraph)) {
 110                 result += convert_trigraph(trigraph);
 111                 pos1 = value.find_first_of ("?", pos = pos1+3);
 112             }
 113             else {
 114                 result += value[pos1];
 115                 pos1 = value.find_first_of ("?", pos = pos1+1);
 116             }
 117         } while (StringT::npos != pos1);
 118         result += value.substr(pos);
 119     }
 120     else {
 121         result = value;
 122     }
 123     return result;
 124 }
 125
 126 ///////////////////////////////////////////////////////////////////////////////
 127 }   // namespace impl
 128 }   // namespace cpplexer
 129 }   // namespace wave
 130 }   // namespace boost
 131
 132 // the suffix header occurs after all of the code
 133 #ifdef BOOST_HAS_ABI_HEADERS
 134 #include BOOST_ABI_SUFFIX
 135 #endif
 136
 137 #endif // !defined(CONVERT_TRIGRAPHS_HK050403_INCLUDED)
 138
 139