boost/boost/regex/v4/regex_iterator.hpp

   1 /*
   2  *
   3  * Copyright (c) 2003
   4  * Dr John Maddock
   5  *
   6  * Use, modification and distribution are subject to the
   7  * Boost Software License, Version 1.0. (See accompanying file
   8  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9  *
  10  */
  11
  12  /*
  13   *   LOCATION:    see http://www.boost.org for most recent version.
  14   *   FILE         regex_iterator.hpp
  15   *   VERSION      see <boost/version.hpp>
  16   *   DESCRIPTION: Provides regex_iterator implementation.
  17   */
  18
  19 #ifndef BOOST_REGEX_V4_REGEX_ITERATOR_HPP
  20 #define BOOST_REGEX_V4_REGEX_ITERATOR_HPP
  21
  22 #include <boost/shared_ptr.hpp>
  23
  24 namespace boost{
  25
  26 #ifdef BOOST_HAS_ABI_HEADERS
  27 #  include BOOST_ABI_PREFIX
  28 #endif
  29
  30 template <class BidirectionalIterator,
  31           class charT,
  32           class traits,
  33           class Allocator>
  34 class regex_iterator_implementation
  35 {
  36    typedef basic_regex<charT, traits, Allocator> regex_type;
  37
  38    match_results<BidirectionalIterator> what;  // current match
  39    BidirectionalIterator                base;  // start of sequence
  40    BidirectionalIterator                end;   // end of sequence
  41    const regex_type*                    pre;   // the expression
  42    match_flag_type                      flags; // flags for matching
  43
  44 public:
  45    regex_iterator_implementation(const regex_type* p, BidirectionalIterator last, match_flag_type f)
  46       : base(), end(last), pre(p), flags(f){}
  47    bool init(BidirectionalIterator first)
  48    {
  49       base = first;
  50       return regex_search(first, end, what, *pre, flags);
  51    }
  52    bool compare(const regex_iterator_implementation& that)
  53    {
  54       if(this == &that) return true;
  55       return (pre == that.pre) && (end == that.end) && (flags == that.flags) && (what[0].first == that.what[0].first) && (what[0].second == that.what[0].second);
  56    }
  57    const match_results<BidirectionalIterator>& get()
  58    { return what; }
  59    bool next()
  60    {
  61       if(what.prefix().first != what[0].second)
  62          flags |= match_prev_avail;
  63       BidirectionalIterator next_start = what[0].second;
  64       match_flag_type f(flags);
  65       if(!what.length())
  66          f |= regex_constants::match_not_initial_null;
  67       bool result = regex_search(next_start, end, what, *pre, f);
  68       if(result)
  69          what.set_base(base);
  70       return result;
  71    }
  72 };
  73
  74 template <class BidirectionalIterator,
  75           class charT = BOOST_DEDUCED_TYPENAME re_detail::regex_iterator_traits<BidirectionalIterator>::value_type,
  76           class traits = regex_traits<charT>,
  77           class Allocator = BOOST_DEFAULT_ALLOCATOR(charT) >
  78 class regex_iterator
  79 #ifndef BOOST_NO_STD_ITERATOR
  80    : public std::iterator<
  81          std::forward_iterator_tag,
  82          match_results<BidirectionalIterator>,
  83          typename re_detail::regex_iterator_traits<BidirectionalIterator>::difference_type,
  84          const match_results<BidirectionalIterator>*,
  85          const match_results<BidirectionalIterator>& >
  86 #endif
  87 {
  88 private:
  89    typedef regex_iterator_implementation<BidirectionalIterator, charT, traits, Allocator> impl;
  90    typedef shared_ptr<impl> pimpl;
  91 public:
  92    typedef          basic_regex<charT, traits, Allocator>                   regex_type;
  93    typedef          match_results<BidirectionalIterator>                    value_type;
  94    typedef typename re_detail::regex_iterator_traits<BidirectionalIterator>::difference_type
  95                                                                             difference_type;
  96    typedef          const value_type*                                       pointer;
  97    typedef          const value_type&                                       reference;
  98    typedef          std::forward_iterator_tag                               iterator_category;
  99
 100    regex_iterator(){}
 101    regex_iterator(BidirectionalIterator a, BidirectionalIterator b,
 102                   const regex_type& re,
 103                   match_flag_type m = match_default)
 104                   : pdata(new impl(&re, b, m))
 105    {
 106       if(!pdata->init(a))
 107       {
 108          pdata.reset();
 109       }
 110    }
 111    regex_iterator(const regex_iterator& that)
 112       : pdata(that.pdata) {}
 113    regex_iterator& operator=(const regex_iterator& that)
 114    {
 115       pdata = that.pdata;
 116       return *this;
 117    }
 118    bool operator==(const regex_iterator& that)const
 119    {
 120       if((pdata.get() == 0) || (that.pdata.get() == 0))
 121          return pdata.get() == that.pdata.get();
 122       return pdata->compare(*(that.pdata.get()));
 123    }
 124    bool operator!=(const regex_iterator& that)const
 125    { return !(*this == that); }
 126    const value_type& operator*()const
 127    { return pdata->get(); }
 128    const value_type* operator->()const
 129    { return &(pdata->get()); }
 130    regex_iterator& operator++()
 131    {
 132       cow();
 133       if(0 == pdata->next())
 134       {
 135          pdata.reset();
 136       }
 137       return *this;
 138    }
 139    regex_iterator operator++(int)
 140    {
 141       regex_iterator result(*this);
 142       ++(*this);
 143       return result;
 144    }
 145 private:
 146
 147    pimpl pdata;
 148
 149    void cow()
 150    {
 151       // copy-on-write
 152       if(pdata.get() && !pdata.unique())
 153       {
 154          pdata.reset(new impl(*(pdata.get())));
 155       }
 156    }
 157 };
 158
 159 typedef regex_iterator<const char*> cregex_iterator;
 160 typedef regex_iterator<std::string::const_iterator> sregex_iterator;
 161 #ifndef BOOST_NO_WREGEX
 162 typedef regex_iterator<const wchar_t*> wcregex_iterator;
 163 typedef regex_iterator<std::wstring::const_iterator> wsregex_iterator;
 164 #endif
 165
 166 #ifdef BOOST_HAS_ABI_HEADERS
 167 #  include BOOST_ABI_SUFFIX
 168 #endif
 169
 170 } // namespace boost
 171
 172 #endif // BOOST_REGEX_V4_REGEX_ITERATOR_HPP
 173