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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 regex_split.hpp |
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15 * VERSION see <boost/version.hpp> |
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16 * DESCRIPTION: Implements regex_split and associated functions. |
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17 * Note this is an internal header file included |
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18 * by regex.hpp, do not include on its own. |
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19 */ |
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20 |
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21 #ifndef BOOST_REGEX_SPLIT_HPP |
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22 #define BOOST_REGEX_SPLIT_HPP |
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23 |
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24 namespace boost{ |
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25 |
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26 #ifdef BOOST_MSVC |
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27 #pragma warning(push) |
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28 #pragma warning(disable: 4103) |
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29 #endif |
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30 #ifdef BOOST_HAS_ABI_HEADERS |
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31 # include BOOST_ABI_PREFIX |
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32 #endif |
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33 #ifdef BOOST_MSVC |
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34 #pragma warning(pop) |
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35 #endif |
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36 |
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37 #ifdef BOOST_MSVC |
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38 # pragma warning(push) |
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39 # pragma warning(disable: 4800) |
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40 #endif |
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41 |
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42 namespace re_detail{ |
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43 |
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44 template <class charT> |
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45 const basic_regex<charT>& get_default_expression(charT) |
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46 { |
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47 static const charT expression_text[4] = { '\\', 's', '+', '\00', }; |
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48 static const basic_regex<charT> e(expression_text); |
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49 return e; |
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50 } |
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51 |
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52 template <class OutputIterator, class charT, class Traits1, class Alloc1> |
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53 class split_pred |
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54 { |
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55 typedef std::basic_string<charT, Traits1, Alloc1> string_type; |
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56 typedef typename string_type::const_iterator iterator_type; |
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57 iterator_type* p_last; |
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58 OutputIterator* p_out; |
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59 std::size_t* p_max; |
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60 std::size_t initial_max; |
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61 public: |
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62 split_pred(iterator_type* a, OutputIterator* b, std::size_t* c) |
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63 : p_last(a), p_out(b), p_max(c), initial_max(*c) {} |
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64 |
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65 bool operator()(const match_results<iterator_type>& what); |
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66 }; |
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67 |
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68 template <class OutputIterator, class charT, class Traits1, class Alloc1> |
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69 bool split_pred<OutputIterator, charT, Traits1, Alloc1>::operator() |
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70 (const match_results<iterator_type>& what) |
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71 { |
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72 *p_last = what[0].second; |
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73 if(what.size() > 1) |
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74 { |
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75 // output sub-expressions only: |
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76 for(unsigned i = 1; i < what.size(); ++i) |
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77 { |
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78 *(*p_out) = what.str(i); |
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79 ++(*p_out); |
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80 if(0 == --*p_max) return false; |
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81 } |
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82 return *p_max != 0; |
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83 } |
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84 else |
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85 { |
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86 // output $` only if it's not-null or not at the start of the input: |
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87 const sub_match<iterator_type>& sub = what[-1]; |
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88 if((sub.first != sub.second) || (*p_max != initial_max)) |
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89 { |
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90 *(*p_out) = sub.str(); |
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91 ++(*p_out); |
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92 return --*p_max; |
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93 } |
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94 } |
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95 // |
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96 // initial null, do nothing: |
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97 return true; |
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98 } |
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99 |
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100 } // namespace re_detail |
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101 |
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102 template <class OutputIterator, class charT, class Traits1, class Alloc1, class Traits2> |
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103 std::size_t regex_split(OutputIterator out, |
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104 std::basic_string<charT, Traits1, Alloc1>& s, |
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105 const basic_regex<charT, Traits2>& e, |
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106 match_flag_type flags, |
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107 std::size_t max_split) |
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108 { |
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109 typedef typename std::basic_string<charT, Traits1, Alloc1>::const_iterator ci_t; |
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110 typedef typename match_results<ci_t>::allocator_type match_allocator; |
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111 ci_t last = s.begin(); |
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112 std::size_t init_size = max_split; |
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113 re_detail::split_pred<OutputIterator, charT, Traits1, Alloc1> pred(&last, &out, &max_split); |
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114 ci_t i, j; |
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115 i = s.begin(); |
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116 j = s.end(); |
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117 regex_grep(pred, i, j, e, flags); |
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118 // |
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119 // if there is still input left, do a final push as long as max_split |
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120 // is not exhausted, and we're not splitting sub-expressions rather |
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121 // than whitespace: |
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122 if(max_split && (last != s.end()) && (e.mark_count() == 1)) |
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123 { |
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124 *out = std::basic_string<charT, Traits1, Alloc1>((ci_t)last, (ci_t)s.end()); |
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125 ++out; |
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126 last = s.end(); |
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127 --max_split; |
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128 } |
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129 // |
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130 // delete from the string everything that has been processed so far: |
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131 s.erase(0, last - s.begin()); |
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132 // |
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133 // return the number of new records pushed: |
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134 return init_size - max_split; |
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135 } |
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136 |
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137 template <class OutputIterator, class charT, class Traits1, class Alloc1, class Traits2> |
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138 inline std::size_t regex_split(OutputIterator out, |
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139 std::basic_string<charT, Traits1, Alloc1>& s, |
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140 const basic_regex<charT, Traits2>& e, |
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141 match_flag_type flags = match_default) |
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142 { |
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143 return regex_split(out, s, e, flags, UINT_MAX); |
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144 } |
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145 |
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146 template <class OutputIterator, class charT, class Traits1, class Alloc1> |
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147 inline std::size_t regex_split(OutputIterator out, |
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148 std::basic_string<charT, Traits1, Alloc1>& s) |
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149 { |
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150 return regex_split(out, s, re_detail::get_default_expression(charT(0)), match_default, UINT_MAX); |
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151 } |
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152 |
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153 #ifdef BOOST_MSVC |
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154 # pragma warning(pop) |
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155 #endif |
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156 |
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157 #ifdef BOOST_MSVC |
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158 #pragma warning(push) |
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159 #pragma warning(disable: 4103) |
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160 #endif |
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161 #ifdef BOOST_HAS_ABI_HEADERS |
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162 # include BOOST_ABI_SUFFIX |
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163 #endif |
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164 #ifdef BOOST_MSVC |
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165 #pragma warning(pop) |
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166 #endif |
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167 |
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168 } // namespace boost |
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169 |
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170 #endif |
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171 |
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172 |