Chris@16: /*=============================================================================
Chris@16:     Boost.Wave: A Standard compliant C++ preprocessor library
Chris@16: 
Chris@16:     Grammar for universal character validation (see C++ standard: Annex E)
Chris@16:     
Chris@16:     http://www.boost.org/
Chris@16: 
Chris@16:     Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
Chris@16:     Software License, Version 1.0. (See accompanying file
Chris@16:     LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: #if !defined(CONVERT_TRIGRAPHS_HK050403_INCLUDED)
Chris@16: #define CONVERT_TRIGRAPHS_HK050403_INCLUDED
Chris@16: 
Chris@16: #include <boost/wave/wave_config.hpp>
Chris@16: #include <boost/wave/cpplexer/cpplexer_exceptions.hpp>
Chris@16: 
Chris@16: // this must occur after all of the includes and before any code appears
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost {
Chris@16: namespace wave {
Chris@16: namespace cpplexer {
Chris@16: namespace impl {
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  Test, whether the given string represents a valid trigraph sequence
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename StringT>
Chris@16: inline bool 
Chris@16: is_trigraph(StringT const& trigraph)
Chris@16: {
Chris@16:     if (trigraph.size() < 3 || '?' != trigraph[0] || '?' != trigraph[1])
Chris@16:         return false;
Chris@16:         
Chris@16:     switch (trigraph[2]) {
Chris@16:     case '\'': case '=': case '/': case '(':
Chris@16:     case ')':  case '<': case '>': case '!':
Chris@16:     case '-':
Chris@16:         break;
Chris@16: 
Chris@16:     default:
Chris@16:         return false;
Chris@16:     }
Chris@16: 
Chris@16:     return true;
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  convert_trigraph
Chris@16: //
Chris@16: //    The function convert_trigraph() converts a single trigraph character 
Chris@16: //    sequence into the corresponding character.
Chris@16: //
Chris@16: //    If the given character sequence doesn't form a valid trigraph sequence
Chris@16: //    no conversion is performed. 
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename StringT>
Chris@16: inline StringT
Chris@16: convert_trigraph(StringT const &trigraph)
Chris@16: {
Chris@16: StringT result (trigraph);
Chris@16: 
Chris@16:     if (is_trigraph(trigraph)) {
Chris@16:         switch (trigraph[2]) {
Chris@16:         case '\'':  result = "^"; break;
Chris@16:         case '=':   result = "#"; break;
Chris@16:         case '/':   result = "\\"; break;
Chris@16:         case '(':   result = "["; break;
Chris@16:         case ')':   result = "]"; break;
Chris@16:         case '<':   result = "{"; break;
Chris@16:         case '>':   result = "}"; break;
Chris@16:         case '!':   result = "|"; break;
Chris@16:         case '-':   result = "~"; break;
Chris@16:         }
Chris@16:     }
Chris@16:     return result;
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  convert_trigraphs
Chris@16: //
Chris@16: //    The function convert_trigraph() converts all trigraphs in the given 
Chris@16: //    string into the corresponding characters.
Chris@16: //
Chris@16: //    If one of the given character sequences doesn't form a valid trigraph 
Chris@16: //    sequence no conversion is performed. 
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <typename StringT>
Chris@16: inline StringT
Chris@16: convert_trigraphs(StringT const &value)
Chris@16: {
Chris@16:     StringT result;
Chris@16:     typename StringT::size_type pos = 0;
Chris@16:     typename StringT::size_type pos1 = value.find_first_of ("?", 0);
Chris@16:     if (StringT::npos != pos1) {
Chris@16:         do {
Chris@16:             result += value.substr(pos, pos1-pos);
Chris@16:             StringT trigraph (value.substr(pos1)); 
Chris@16:             if (is_trigraph(trigraph)) {
Chris@16:                 result += convert_trigraph(trigraph);
Chris@16:                 pos1 = value.find_first_of ("?", pos = pos1+3);
Chris@16:             }
Chris@16:             else {
Chris@16:                 result += value[pos1];
Chris@16:                 pos1 = value.find_first_of ("?", pos = pos1+1);
Chris@16:             }
Chris@16:         } while (StringT::npos != pos1);
Chris@16:         result += value.substr(pos);
Chris@16:     }
Chris@16:     else {
Chris@16:         result = value;
Chris@16:     }
Chris@16:     return result;
Chris@16: }
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: }   // namespace impl           
Chris@16: }   // namespace cpplexer
Chris@16: }   // namespace wave
Chris@16: }   // namespace boost
Chris@16: 
Chris@16: // the suffix header occurs after all of the code
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: 
Chris@16: #endif // !defined(CONVERT_TRIGRAPHS_HK050403_INCLUDED)
Chris@16: 
Chris@16: