/* * * 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