sl@0: // Boost token_iterator.hpp  -------------------------------------------------//
sl@0: 
sl@0: // Copyright John R. Bandela 2001
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: 
sl@0: // See http://www.boost.org/libs/tokenizer for documentation.
sl@0: 
sl@0: // Revision History:
sl@0: // 16 Jul 2003   John Bandela
sl@0: //      Allowed conversions from convertible base iterators
sl@0: // 03 Jul 2003   John Bandela
sl@0: //      Converted to new iterator adapter
sl@0: 
sl@0: 
sl@0: 
sl@0: #ifndef BOOST_TOKENIZER_POLICY_JRB070303_HPP_
sl@0: #define BOOST_TOKENIZER_POLICY_JRB070303_HPP_
sl@0: 
sl@0: #include<boost/assert.hpp>
sl@0: #include<boost/iterator/iterator_adaptor.hpp>
sl@0: #include<boost/iterator/detail/minimum_category.hpp>
sl@0: #include<boost/token_functions.hpp>
sl@0: #include<utility>
sl@0: 
sl@0: namespace boost
sl@0: {
sl@0:   template <class TokenizerFunc, class Iterator, class Type>
sl@0:   class token_iterator
sl@0:       : public iterator_facade<
sl@0:             token_iterator<TokenizerFunc, Iterator, Type>
sl@0:           , Type
sl@0:           , typename detail::minimum_category<
sl@0:                 forward_traversal_tag
sl@0:               , typename iterator_traversal<Iterator>::type
sl@0:             >::type 
sl@0:           , const Type&
sl@0:         >
sl@0:   {
sl@0: 
sl@0:       friend class iterator_core_access;
sl@0: 
sl@0:       TokenizerFunc f_;
sl@0:       Iterator begin_;
sl@0:       Iterator end_;
sl@0:       bool valid_;
sl@0:       Type tok_;
sl@0: 
sl@0:       void increment(){
sl@0:           BOOST_ASSERT(valid_);
sl@0:           valid_ = f_(begin_,end_,tok_);
sl@0:       }
sl@0: 
sl@0:       const Type&  dereference() const {
sl@0:           BOOST_ASSERT(valid_);
sl@0:           return tok_;
sl@0:       }
sl@0:       template<class Other>
sl@0:       bool equal(const Other& a) const{
sl@0:           return (a.valid_ && valid_)
sl@0:               ?( (a.begin_==begin_) && (a.end_ == end_) )
sl@0:               :(a.valid_==valid_);
sl@0: 
sl@0:       }
sl@0: 
sl@0:       void initialize(){
sl@0:           if(valid_) return;
sl@0:           f_.reset();
sl@0:           valid_ = (begin_ != end_)?
sl@0:               f_(begin_,end_,tok_):false;
sl@0:       }
sl@0:   public:
sl@0:       token_iterator():begin_(),end_(),valid_(false),tok_() { }
sl@0: 
sl@0:       token_iterator(TokenizerFunc f, Iterator begin, Iterator e = Iterator())
sl@0:           : f_(f),begin_(begin),end_(e),valid_(false),tok_(){ initialize(); }
sl@0: 
sl@0:       token_iterator(Iterator begin, Iterator e = Iterator())
sl@0:             : f_(),begin_(begin),end_(e),valid_(false),tok_() {initialize();}
sl@0: 
sl@0:       template<class OtherIter>
sl@0:       token_iterator(
sl@0:             token_iterator<TokenizerFunc, OtherIter,Type> const& t
sl@0:             , typename enable_if_convertible<OtherIter, Iterator>::type* = 0)
sl@0:             : f_(t.tokenizer_function()),begin_(t.base())
sl@0:             ,end_(t.end()),valid_(t.at_end()),tok_(t.current_token()) {}
sl@0: 
sl@0:       Iterator base()const{return begin_;}
sl@0: 
sl@0:       Iterator end()const{return end_;};
sl@0: 
sl@0:       TokenizerFunc tokenizer_function()const{return f_;}
sl@0: 
sl@0:       Type current_token()const{return tok_;}
sl@0: 
sl@0:       bool at_end()const{return valid_;}
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0:   };
sl@0:     template <
sl@0:         class TokenizerFunc = char_delimiters_separator<char>, 
sl@0:         class Iterator = std::string::const_iterator,
sl@0:         class Type = std::string
sl@0:     >
sl@0:     class token_iterator_generator {
sl@0: 
sl@0:     private: 
sl@0:     public:
sl@0:         typedef token_iterator<TokenizerFunc,Iterator,Type> type;
sl@0:     };
sl@0:     
sl@0:     
sl@0:     // Type has to be first because it needs to be explicitly specified
sl@0:     // because there is no way the function can deduce it.
sl@0:     template<class Type, class Iterator, class TokenizerFunc>
sl@0:         typename token_iterator_generator<TokenizerFunc,Iterator,Type>::type 
sl@0:     make_token_iterator(Iterator begin, Iterator end,const TokenizerFunc& fun){
sl@0:         typedef typename 
sl@0:             token_iterator_generator<TokenizerFunc,Iterator,Type>::type ret_type;
sl@0:         return ret_type(fun,begin,end);
sl@0:     }
sl@0: 
sl@0: } // namespace boost
sl@0: 
sl@0: #endif