source: NonGTP/Boost/boost/wave/cpplexer/convert_trigraphs.hpp @ 857

Revision 857, 4.1 KB checked in by igarcia, 19 years ago (diff)
Line 
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) 2001-2005 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/cpplexer/cpplexer_exceptions.hpp>
16
17///////////////////////////////////////////////////////////////////////////////
18namespace boost {
19namespace wave {
20namespace cpplexer {
21namespace impl {
22
23///////////////////////////////////////////////////////////////////////////////
24//
25//
26//
27///////////////////////////////////////////////////////////////////////////////
28template <typename StringT>
29inline bool
30is_trigraph(StringT const& trigraph)
31{
32    if (trigraph.size() < 3 || '?' != trigraph[0] || '?' != trigraph[1])
33        return false;
34       
35    switch (trigraph[2]) {
36    case '\'': case '=': case '/': case '(':
37    case ')':  case '<': case '>': case '!':
38    case '-':
39        break;
40
41    default:
42        return false;
43    }
44
45    return true;
46}
47
48///////////////////////////////////////////////////////////////////////////////
49//
50//  convert_trigraph
51//
52//    The function convert_trigraph() converts a single trigraph character
53//    sequence into the corresponding character.
54//
55//    If the given character sequence doesn't form a valid trigraph sequence
56//    no conversion is performed.
57//
58///////////////////////////////////////////////////////////////////////////////
59template <typename StringT>
60inline StringT
61convert_trigraph(StringT const &trigraph, int line, int column,
62    StringT const &file_name)
63{
64StringT result (trigraph);
65
66    if (is_trigraph(trigraph)) {
67        switch (trigraph[2]) {
68        case '\'':  result = "^"; break;
69        case '=':   result = "#"; break;
70        case '/':   result = "\\"; break;
71        case '(':   result = "["; break;
72        case ')':   result = "]"; break;
73        case '<':   result = "{"; break;
74        case '>':   result = "}"; break;
75        case '!':   result = "|"; break;
76        case '-':   result = "~"; break;
77        }
78    }
79    return result;
80}
81
82///////////////////////////////////////////////////////////////////////////////
83//
84//  convert_trigraphs
85//
86//    The function convert_trigraph() converts all trigraphs in the given
87//    string into the corresponding characters.
88//
89//    If one of the given character sequences doesn't form a valid trigraph
90//    sequence no conversion is performed.
91//
92///////////////////////////////////////////////////////////////////////////////
93template <typename StringT>
94inline StringT
95convert_trigraphs(StringT const &value, int line, int column,
96    StringT const &file_name)
97{
98    StringT result;
99    typename StringT::size_type pos = 0;
100    typename StringT::size_type pos1 = value.find_first_of ("?", 0);
101    if (StringT::npos != pos1) {
102        do {
103            result += value.substr(pos, pos1-pos);
104            StringT trigraph (value.substr(pos1));
105            if (is_trigraph(trigraph)) {
106                result += convert_trigraph(trigraph, line, column, file_name);
107                pos1 = value.find_first_of ("?", pos = pos1+3);
108            }
109            else {
110                result += value[pos1];
111                pos1 = value.find_first_of ("?", pos = pos1+1);
112            }
113        } while (StringT::npos != pos1);
114        result += value.substr(pos);
115    }
116    else {
117        result = value;
118    }
119    return result;
120}
121
122///////////////////////////////////////////////////////////////////////////////
123}   // namespace impl           
124}   // namespace cpplexer
125}   // namespace wave
126}   // namespace boost
127
128#endif // !defined(CONVERT_TRIGRAPHS_HK050403_INCLUDED)
129
130
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