[857] | 1 | /*
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| 2 | *
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| 3 | * Copyright (c) 1998-2002
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| 4 | * John Maddock
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| 5 | *
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| 6 | * Use, modification and distribution are subject to the
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| 7 | * Boost Software License, Version 1.0. (See accompanying file
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| 8 | * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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| 9 | *
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| 10 | */
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| 11 |
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| 12 | /*
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| 13 | * LOCATION: see http://www.boost.org for most recent version.
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| 14 | * FILE: primary_transform.hpp
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| 15 | * VERSION: see <boost/version.hpp>
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| 16 | * DESCRIPTION: Heuristically determines the sort string format in use
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| 17 | * by the current locale.
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| 18 | */
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| 19 |
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| 20 | #ifndef BOOST_REGEX_PRIMARY_TRANSFORM
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| 21 | #define BOOST_REGEX_PRIMARY_TRANSFORM
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| 22 |
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| 23 | #ifdef BOOST_HAS_ABI_HEADERS
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| 24 | # include BOOST_ABI_PREFIX
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| 25 | #endif
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| 26 |
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| 27 | namespace boost{
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| 28 | namespace re_detail{
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| 29 |
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| 30 |
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| 31 | enum{
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| 32 | sort_C,
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| 33 | sort_fixed,
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| 34 | sort_delim,
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| 35 | sort_unknown
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| 36 | };
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| 37 |
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| 38 | template <class S, class charT>
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| 39 | unsigned count_chars(const S& s, charT c)
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| 40 | {
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| 41 | //
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| 42 | // Count how many occurances of character c occur
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| 43 | // in string s: if c is a delimeter between collation
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| 44 | // fields, then this should be the same value for all
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| 45 | // sort keys:
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| 46 | //
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| 47 | unsigned int count = 0;
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| 48 | for(unsigned pos = 0; pos < s.size(); ++pos)
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| 49 | {
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| 50 | if(s[pos] == c) ++count;
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| 51 | }
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| 52 | return count;
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| 53 | }
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| 54 |
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| 55 |
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| 56 | template <class traits, class charT>
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| 57 | unsigned find_sort_syntax(const traits* pt, charT* delim)
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| 58 | {
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| 59 | //
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| 60 | // compare 'a' with 'A' to see how similar they are,
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| 61 | // should really use a-accute but we can't portably do that,
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| 62 | //
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| 63 | typedef typename traits::string_type string_type;
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| 64 | typedef typename traits::char_type char_type;
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| 65 |
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| 66 | // Suppress incorrect warning for MSVC
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| 67 | (void)pt;
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| 68 |
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| 69 | char_type a[2] = {'a', '\0', };
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| 70 | string_type sa(pt->transform(a, a+1));
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| 71 | if(sa == a)
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| 72 | {
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| 73 | *delim = 0;
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| 74 | return sort_C;
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| 75 | }
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| 76 | char_type A[2] = { 'A', '\0', };
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| 77 | string_type sA(pt->transform(A, A+1));
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| 78 | char_type c[2] = { ';', '\0', };
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| 79 | string_type sc(pt->transform(c, c+1));
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| 80 |
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| 81 | int pos = 0;
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| 82 | while((pos <= static_cast<int>(sa.size())) && (pos <= static_cast<int>(sA.size())) && (sa[pos] == sA[pos])) ++pos;
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| 83 | --pos;
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| 84 | if(pos < 0)
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| 85 | {
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| 86 | *delim = 0;
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| 87 | return sort_unknown;
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| 88 | }
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| 89 | //
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| 90 | // at this point sa[pos] is either the end of a fixed width field
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| 91 | // or the character that acts as a delimiter:
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| 92 | //
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| 93 | charT maybe_delim = sa[pos];
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| 94 | if((pos != 0) && (count_chars(sa, maybe_delim) == count_chars(sA, maybe_delim)) && (count_chars(sa, maybe_delim) == count_chars(sc, maybe_delim)))
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| 95 | {
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| 96 | *delim = maybe_delim;
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| 97 | return sort_delim;
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| 98 | }
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| 99 | //
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| 100 | // OK doen't look like a delimiter, try for fixed width field:
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| 101 | //
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| 102 | if((sa.size() == sA.size()) && (sa.size() == sc.size()))
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| 103 | {
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| 104 | // note assumes that the fixed width field is less than
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| 105 | // (numeric_limits<charT>::max)(), should be true for all types
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| 106 | // I can't imagine 127 character fields...
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| 107 | *delim = static_cast<charT>(++pos);
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| 108 | return sort_fixed;
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| 109 | }
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| 110 | //
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| 111 | // don't know what it is:
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| 112 | //
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| 113 | *delim = 0;
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| 114 | return sort_unknown;
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| 115 | }
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| 116 |
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| 117 |
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| 118 | } // namespace re_detail
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| 119 | } // namespace boost
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| 120 |
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| 121 | #ifdef BOOST_HAS_ABI_HEADERS
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| 122 | # include BOOST_ABI_SUFFIX
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| 123 | #endif
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| 124 |
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| 125 | #endif
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| 126 |
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| 127 |
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| 128 |
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| 129 |
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| 130 |
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| 131 |
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| 132 |
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