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