/* | |
* | |
* Copyright (c) 1998-2002 | |
* John Maddock | |
* | |
* Use, modification and distribution are subject to the | |
* Boost Software License, Version 1.0. (See accompanying file | |
* LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
* | |
*/ | |
/* | |
* LOCATION: see http://www.boost.org for most recent version. | |
* FILE: primary_transform.hpp | |
* VERSION: see <boost/version.hpp> | |
* DESCRIPTION: Heuristically determines the sort string format in use | |
* by the current locale. | |
*/ | |
#ifndef BOOST_REGEX_PRIMARY_TRANSFORM | |
#define BOOST_REGEX_PRIMARY_TRANSFORM | |
#ifdef BOOST_MSVC | |
#pragma warning(push) | |
#pragma warning(disable: 4103) | |
#endif | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_PREFIX | |
#endif | |
#ifdef BOOST_MSVC | |
#pragma warning(pop) | |
#endif | |
namespace boost{ | |
namespace re_detail{ | |
enum{ | |
sort_C, | |
sort_fixed, | |
sort_delim, | |
sort_unknown | |
}; | |
template <class S, class charT> | |
unsigned count_chars(const S& s, charT c) | |
{ | |
// | |
// Count how many occurances of character c occur | |
// in string s: if c is a delimeter between collation | |
// fields, then this should be the same value for all | |
// sort keys: | |
// | |
unsigned int count = 0; | |
for(unsigned pos = 0; pos < s.size(); ++pos) | |
{ | |
if(s[pos] == c) ++count; | |
} | |
return count; | |
} | |
template <class traits, class charT> | |
unsigned find_sort_syntax(const traits* pt, charT* delim) | |
{ | |
// | |
// compare 'a' with 'A' to see how similar they are, | |
// should really use a-accute but we can't portably do that, | |
// | |
typedef typename traits::string_type string_type; | |
typedef typename traits::char_type char_type; | |
// Suppress incorrect warning for MSVC | |
(void)pt; | |
char_type a[2] = {'a', '\0', }; | |
string_type sa(pt->transform(a, a+1)); | |
if(sa == a) | |
{ | |
*delim = 0; | |
return sort_C; | |
} | |
char_type A[2] = { 'A', '\0', }; | |
string_type sA(pt->transform(A, A+1)); | |
char_type c[2] = { ';', '\0', }; | |
string_type sc(pt->transform(c, c+1)); | |
int pos = 0; | |
while((pos <= static_cast<int>(sa.size())) && (pos <= static_cast<int>(sA.size())) && (sa[pos] == sA[pos])) ++pos; | |
--pos; | |
if(pos < 0) | |
{ | |
*delim = 0; | |
return sort_unknown; | |
} | |
// | |
// at this point sa[pos] is either the end of a fixed width field | |
// or the character that acts as a delimiter: | |
// | |
charT maybe_delim = sa[pos]; | |
if((pos != 0) && (count_chars(sa, maybe_delim) == count_chars(sA, maybe_delim)) && (count_chars(sa, maybe_delim) == count_chars(sc, maybe_delim))) | |
{ | |
*delim = maybe_delim; | |
return sort_delim; | |
} | |
// | |
// OK doen't look like a delimiter, try for fixed width field: | |
// | |
if((sa.size() == sA.size()) && (sa.size() == sc.size())) | |
{ | |
// note assumes that the fixed width field is less than | |
// (numeric_limits<charT>::max)(), should be true for all types | |
// I can't imagine 127 character fields... | |
*delim = static_cast<charT>(++pos); | |
return sort_fixed; | |
} | |
// | |
// don't know what it is: | |
// | |
*delim = 0; | |
return sort_unknown; | |
} | |
} // namespace re_detail | |
} // namespace boost | |
#ifdef BOOST_MSVC | |
#pragma warning(push) | |
#pragma warning(disable: 4103) | |
#endif | |
#ifdef BOOST_HAS_ABI_HEADERS | |
# include BOOST_ABI_SUFFIX | |
#endif | |
#ifdef BOOST_MSVC | |
#pragma warning(pop) | |
#endif | |
#endif | |