1 // Boost token_iterator.hpp -------------------------------------------------// 2 3 // Copyright John R. Bandela 2001 4 // Distributed under the Boost Software License, Version 1.0. (See 5 // accompanying file LICENSE_1_0.txt or copy at 6 // http://www.boost.org/LICENSE_1_0.txt) 7 8 // See http://www.boost.org/libs/tokenizer for documentation. 9 10 // Revision History: 11 // 16 Jul 2003 John Bandela 12 // Allowed conversions from convertible base iterators 13 // 03 Jul 2003 John Bandela 14 // Converted to new iterator adapter 15 16 17 18 #ifndef BOOST_TOKENIZER_POLICY_JRB070303_HPP_ 19 #define BOOST_TOKENIZER_POLICY_JRB070303_HPP_ 20 21 #include <boost/assert.hpp> 22 #include <boost/iterator/iterator_adaptor.hpp> 23 #include <boost/iterator/minimum_category.hpp> 24 #include <boost/token_functions.hpp> 25 #include <utility> 26 27 namespace boost 28 { 29 template <class TokenizerFunc, class Iterator, class Type> 30 class token_iterator 31 : public iterator_facade< 32 token_iterator<TokenizerFunc, Iterator, Type> 33 , Type 34 , typename iterators::minimum_category< 35 forward_traversal_tag 36 , typename iterator_traversal<Iterator>::type 37 >::type 38 , const Type& 39 > 40 { 41 42 #ifdef __DCC__ 43 friend class boost::iterator_core_access; 44 #else 45 friend class iterator_core_access; 46 #endif 47 TokenizerFunc f_; 48 Iterator begin_; 49 Iterator end_; 50 bool valid_; 51 Type tok_; 52 increment()53 void increment(){ 54 BOOST_ASSERT(valid_); 55 valid_ = f_(begin_,end_,tok_); 56 } 57 dereference() const58 const Type& dereference() const { 59 BOOST_ASSERT(valid_); 60 return tok_; 61 } 62 template<class Other> equal(const Other & a) const63 bool equal(const Other& a) const{ 64 return (a.valid_ && valid_) 65 ?( (a.begin_==begin_) && (a.end_ == end_) ) 66 :(a.valid_==valid_); 67 68 } 69 initialize()70 void initialize(){ 71 if(valid_) return; 72 f_.reset(); 73 valid_ = (begin_ != end_)? 74 f_(begin_,end_,tok_):false; 75 } 76 public: token_iterator()77 token_iterator():begin_(),end_(),valid_(false),tok_() { } 78 token_iterator(TokenizerFunc f,Iterator begin,Iterator e=Iterator ())79 token_iterator(TokenizerFunc f, Iterator begin, Iterator e = Iterator()) 80 : f_(f),begin_(begin),end_(e),valid_(false),tok_(){ initialize(); } 81 token_iterator(Iterator begin,Iterator e=Iterator ())82 token_iterator(Iterator begin, Iterator e = Iterator()) 83 : f_(),begin_(begin),end_(e),valid_(false),tok_() {initialize();} 84 85 template<class OtherIter> token_iterator(token_iterator<TokenizerFunc,OtherIter,Type> const & t,typename enable_if_convertible<OtherIter,Iterator>::type * =0)86 token_iterator( 87 token_iterator<TokenizerFunc, OtherIter,Type> const& t 88 , typename enable_if_convertible<OtherIter, Iterator>::type* = 0) 89 : f_(t.tokenizer_function()),begin_(t.base()) 90 ,end_(t.end()),valid_(!t.at_end()),tok_(t.current_token()) {} 91 base() const92 Iterator base()const{return begin_;} 93 end() const94 Iterator end()const{return end_;} 95 tokenizer_function() const96 TokenizerFunc tokenizer_function()const{return f_;} 97 current_token() const98 Type current_token()const{return tok_;} 99 at_end() const100 bool at_end()const{return !valid_;} 101 102 103 104 105 }; 106 template < 107 class TokenizerFunc = char_delimiters_separator<char>, 108 class Iterator = std::string::const_iterator, 109 class Type = std::string 110 > 111 class token_iterator_generator { 112 113 private: 114 public: 115 typedef token_iterator<TokenizerFunc,Iterator,Type> type; 116 }; 117 118 119 // Type has to be first because it needs to be explicitly specified 120 // because there is no way the function can deduce it. 121 template<class Type, class Iterator, class TokenizerFunc> 122 typename token_iterator_generator<TokenizerFunc,Iterator,Type>::type make_token_iterator(Iterator begin,Iterator end,const TokenizerFunc & fun)123 make_token_iterator(Iterator begin, Iterator end,const TokenizerFunc& fun){ 124 typedef typename 125 token_iterator_generator<TokenizerFunc,Iterator,Type>::type ret_type; 126 return ret_type(fun,begin,end); 127 } 128 129 } // namespace boost 130 131 #endif 132