Chris@16: /*
Chris@16:  *
Chris@16:  * Copyright (c) 1998-2002
Chris@16:  * John Maddock
Chris@16:  *
Chris@16:  * Use, modification and distribution are subject to the 
Chris@16:  * Boost 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:  */
Chris@16:  
Chris@16:  /*
Chris@16:   *   LOCATION:    see http://www.boost.org for most recent version.
Chris@16:   *   FILE:        primary_transform.hpp
Chris@16:   *   VERSION:     see <boost/version.hpp>
Chris@16:   *   DESCRIPTION: Heuristically determines the sort string format in use
Chris@16:   *                by the current locale.
Chris@16:   */
Chris@16: 
Chris@16: #ifndef BOOST_REGEX_PRIMARY_TRANSFORM
Chris@16: #define BOOST_REGEX_PRIMARY_TRANSFORM
Chris@16: 
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable: 4103)
Chris@16: #endif
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_PREFIX
Chris@16: #endif
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost{
Chris@16:    namespace re_detail{
Chris@16: 
Chris@16: 
Chris@16: enum{
Chris@16:    sort_C,
Chris@16:    sort_fixed,
Chris@16:    sort_delim,
Chris@16:    sort_unknown
Chris@16: };
Chris@16: 
Chris@16: template <class S, class charT>
Chris@16: unsigned count_chars(const S& s, charT c)
Chris@16: {
Chris@16:    //
Chris@16:    // Count how many occurances of character c occur
Chris@16:    // in string s: if c is a delimeter between collation
Chris@16:    // fields, then this should be the same value for all
Chris@16:    // sort keys:
Chris@16:    //
Chris@16:    unsigned int count = 0;
Chris@16:    for(unsigned pos = 0; pos < s.size(); ++pos)
Chris@16:    {
Chris@16:       if(s[pos] == c) ++count;
Chris@16:    }
Chris@16:    return count;
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16: template <class traits, class charT>
Chris@16: unsigned find_sort_syntax(const traits* pt, charT* delim)
Chris@16: {
Chris@16:    //
Chris@16:    // compare 'a' with 'A' to see how similar they are,
Chris@16:    // should really use a-accute but we can't portably do that,
Chris@16:    //
Chris@16:    typedef typename traits::string_type string_type;
Chris@16:    typedef typename traits::char_type char_type;
Chris@16: 
Chris@16:    // Suppress incorrect warning for MSVC
Chris@16:    (void)pt;
Chris@16: 
Chris@16:    char_type a[2] = {'a', '\0', };
Chris@16:    string_type sa(pt->transform(a, a+1));
Chris@16:    if(sa == a)
Chris@16:    {
Chris@16:       *delim = 0;
Chris@16:       return sort_C;
Chris@16:    }
Chris@16:    char_type A[2] = { 'A', '\0', };
Chris@16:    string_type sA(pt->transform(A, A+1));
Chris@16:    char_type c[2] = { ';', '\0', };
Chris@16:    string_type sc(pt->transform(c, c+1));
Chris@16: 
Chris@16:    int pos = 0;
Chris@16:    while((pos <= static_cast<int>(sa.size())) && (pos <= static_cast<int>(sA.size())) && (sa[pos] == sA[pos])) ++pos;
Chris@16:    --pos;
Chris@16:    if(pos < 0)
Chris@16:    {
Chris@16:       *delim = 0;
Chris@16:       return sort_unknown;
Chris@16:    }
Chris@16:    //
Chris@16:    // at this point sa[pos] is either the end of a fixed width field
Chris@16:    // or the character that acts as a delimiter:
Chris@16:    //
Chris@16:    charT maybe_delim = sa[pos];
Chris@16:    if((pos != 0) && (count_chars(sa, maybe_delim) == count_chars(sA, maybe_delim)) && (count_chars(sa, maybe_delim) == count_chars(sc, maybe_delim)))
Chris@16:    {
Chris@16:       *delim = maybe_delim;
Chris@16:       return sort_delim;
Chris@16:    }
Chris@16:    //
Chris@16:    // OK doen't look like a delimiter, try for fixed width field:
Chris@16:    //
Chris@16:    if((sa.size() == sA.size()) && (sa.size() == sc.size()))
Chris@16:    {
Chris@16:       // note assumes that the fixed width field is less than
Chris@16:       // (numeric_limits<charT>::max)(), should be true for all types
Chris@16:       // I can't imagine 127 character fields...
Chris@16:       *delim = static_cast<charT>(++pos);
Chris@16:       return sort_fixed;
Chris@16:    }
Chris@16:    //
Chris@16:    // don't know what it is:
Chris@16:    //
Chris@16:    *delim = 0;
Chris@16:    return sort_unknown;
Chris@16: }
Chris@16: 
Chris@16: 
Chris@16:    } // namespace re_detail
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable: 4103)
Chris@16: #endif
Chris@16: #ifdef BOOST_HAS_ABI_HEADERS
Chris@16: #  include BOOST_ABI_SUFFIX
Chris@16: #endif
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: