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
27namespace 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
53 void increment(){
54 BOOST_ASSERT(valid_);
55 valid_ = f_(begin_,end_,tok_);
56 }
57
58 const Type& dereference() const {
59 BOOST_ASSERT(valid_);
60 return tok_;
61 }
62 template<class Other>
63 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
70 void initialize(){
71 if(valid_) return;
72 f_.reset();
73 valid_ = (begin_ != end_)?
74 f_(begin_,end_,tok_):false;
75 }
76 public:
77 token_iterator():begin_(),end_(),valid_(false),tok_() { }
78
79 token_iterator(TokenizerFunc f, Iterator begin, Iterator e = Iterator())
80 : f_(f),begin_(begin),end_(e),valid_(false),tok_(){ initialize(); }
81
82 token_iterator(Iterator begin, Iterator e = Iterator())
83 : f_(),begin_(begin),end_(e),valid_(false),tok_() {initialize();}
84
85 template<class OtherIter>
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
92 Iterator base()const{return begin_;}
93
94 Iterator end()const{return end_;}
95
96 TokenizerFunc tokenizer_function()const{return f_;}
97
98 Type current_token()const{return tok_;}
99
100 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
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

source code of include/boost/token_iterator.hpp