boost/token_functions.hpp
// Boost token_functions.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: // 01 Oct 2004 Joaquin M Lopez Munoz // Workaround for a problem with string::assign in msvc-stlport // 06 Apr 2004 John Bandela // Fixed a bug involving using char_delimiter with a true input iterator // 28 Nov 2003 Robert Zeh and John Bandela // Converted into "fast" functions that avoid using += when // the supplied iterator isn't an input_iterator; based on // some work done at Archelon and a version that was checked into // the boost CVS for a short period of time. // 20 Feb 2002 John Maddock // Removed using namespace std declarations and added // workaround for BOOST_NO_STDC_NAMESPACE (the library // can be safely mixed with regex). // 06 Feb 2002 Jeremy Siek // Added char_separator. // 02 Feb 2002 Jeremy Siek // Removed tabs and a little cleanup. #ifndef BOOST_TOKEN_FUNCTIONS_JRB120303_HPP_ #define BOOST_TOKEN_FUNCTIONS_JRB120303_HPP_ #include <vector> #include <stdexcept> #include <string> #include <cctype> #include <algorithm> // for find_if #include <boost/config.hpp> #include <boost/assert.hpp> #include <boost/type_traits/conditional.hpp> #include <boost/type_traits/is_pointer.hpp> #include <boost/detail/workaround.hpp> #include <boost/throw_exception.hpp> #if !defined(BOOST_NO_CWCTYPE) #include <cwctype> #endif // // the following must not be macros if we are to prefix them // with std:: (they shouldn't be macros anyway...) // #ifdef ispunct # undef ispunct #endif #ifdef iswpunct # undef iswpunct #endif #ifdef isspace # undef isspace #endif #ifdef iswspace # undef iswspace #endif // // fix namespace problems: // #ifdef BOOST_NO_STDC_NAMESPACE namespace std{ using ::ispunct; using ::isspace; #if !defined(BOOST_NO_CWCTYPE) using ::iswpunct; using ::iswspace; #endif } #endif namespace boost{ //=========================================================================== // The escaped_list_separator class. Which is a model of TokenizerFunction // An escaped list is a super-set of what is commonly known as a comma // separated value (csv) list.It is separated into fields by a comma or // other character. If the delimiting character is inside quotes, then it is // counted as a regular character.To allow for embedded quotes in a field, // there can be escape sequences using the \ much like C. // The role of the comma, the quotation mark, and the escape // character (backslash \), can be assigned to other characters. struct escaped_list_error : public std::runtime_error{ escaped_list_error(const std::string& what_arg):std::runtime_error(what_arg) { } }; // The out of the box GCC 2.95 on cygwin does not have a char_traits class. // MSVC does not like the following typename template <class Char, class Traits = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type > class escaped_list_separator { private: typedef std::basic_string<Char,Traits> string_type; struct char_eq { Char e_; char_eq(Char e):e_(e) { } bool operator()(Char c) { return Traits::eq(e_,c); } }; string_type escape_; string_type c_; string_type quote_; bool last_; bool is_escape(Char e) { char_eq f(e); return std::find_if(escape_.begin(),escape_.end(),f)!=escape_.end(); } bool is_c(Char e) { char_eq f(e); return std::find_if(c_.begin(),c_.end(),f)!=c_.end(); } bool is_quote(Char e) { char_eq f(e); return std::find_if(quote_.begin(),quote_.end(),f)!=quote_.end(); } template <typename iterator, typename Token> void do_escape(iterator& next,iterator end,Token& tok) { if (++next == end) BOOST_THROW_EXCEPTION(escaped_list_error(std::string("cannot end with escape"))); if (Traits::eq(*next,'n')) { tok+='\n'; return; } else if (is_quote(*next)) { tok+=*next; return; } else if (is_c(*next)) { tok+=*next; return; } else if (is_escape(*next)) { tok+=*next; return; } else BOOST_THROW_EXCEPTION(escaped_list_error(std::string("unknown escape sequence"))); } public: explicit escaped_list_separator(Char e = '\\', Char c = ',',Char q = '\"') : escape_(1,e), c_(1,c), quote_(1,q), last_(false) { } escaped_list_separator(string_type e, string_type c, string_type q) : escape_(e), c_(c), quote_(q), last_(false) { } void reset() {last_=false;} template <typename InputIterator, typename Token> bool operator()(InputIterator& next,InputIterator end,Token& tok) { bool bInQuote = false; tok = Token(); if (next == end) { if (last_) { last_ = false; return true; } else return false; } last_ = false; for (;next != end;++next) { if (is_escape(*next)) { do_escape(next,end,tok); } else if (is_c(*next)) { if (!bInQuote) { // If we are not in quote, then we are done ++next; // The last character was a c, that means there is // 1 more blank field last_ = true; return true; } else tok+=*next; } else if (is_quote(*next)) { bInQuote=!bInQuote; } else { tok += *next; } } return true; } }; //=========================================================================== // The classes here are used by offset_separator and char_separator to implement // faster assigning of tokens using assign instead of += namespace tokenizer_detail { //=========================================================================== // Tokenizer was broken for wide character separators, at least on Windows, since // CRT functions isspace etc only expect values in [0, 0xFF]. Debug build asserts // if higher values are passed in. The traits extension class should take care of this. // Assuming that the conditional will always get optimized out in the function // implementations, argument types are not a problem since both forms of character classifiers // expect an int. #if !defined(BOOST_NO_CWCTYPE) template<typename traits, int N> struct traits_extension_details : public traits { typedef typename traits::char_type char_type; static bool isspace(char_type c) { return std::iswspace(c) != 0; } static bool ispunct(char_type c) { return std::iswpunct(c) != 0; } }; template<typename traits> struct traits_extension_details<traits, 1> : public traits { typedef typename traits::char_type char_type; static bool isspace(char_type c) { return std::isspace(c) != 0; } static bool ispunct(char_type c) { return std::ispunct(c) != 0; } }; #endif // In case there is no cwctype header, we implement the checks manually. // We make use of the fact that the tested categories should fit in ASCII. template<typename traits> struct traits_extension : public traits { typedef typename traits::char_type char_type; static bool isspace(char_type c) { #if !defined(BOOST_NO_CWCTYPE) return traits_extension_details<traits, sizeof(char_type)>::isspace(c); #else return static_cast< unsigned >(c) <= 255 && std::isspace(c) != 0; #endif } static bool ispunct(char_type c) { #if !defined(BOOST_NO_CWCTYPE) return traits_extension_details<traits, sizeof(char_type)>::ispunct(c); #else return static_cast< unsigned >(c) <= 255 && std::ispunct(c) != 0; #endif } }; // The assign_or_plus_equal struct contains functions that implement // assign, +=, and clearing based on the iterator type. The // generic case does nothing for plus_equal and clearing, while // passing through the call for assign. // // When an input iterator is being used, the situation is reversed. // The assign method does nothing, plus_equal invokes operator +=, // and the clearing method sets the supplied token to the default // token constructor's result. // template<class IteratorTag> struct assign_or_plus_equal { template<class Iterator, class Token> static void assign(Iterator b, Iterator e, Token &t) { t.assign(b, e); } template<class Token, class Value> static void plus_equal(Token &, const Value &) { } // If we are doing an assign, there is no need for the // the clear. // template<class Token> static void clear(Token &) { } }; template <> struct assign_or_plus_equal<std::input_iterator_tag> { template<class Iterator, class Token> static void assign(Iterator , Iterator , Token &) { } template<class Token, class Value> static void plus_equal(Token &t, const Value &v) { t += v; } template<class Token> static void clear(Token &t) { t = Token(); } }; template<class Iterator> struct pointer_iterator_category{ typedef std::random_access_iterator_tag type; }; template<class Iterator> struct class_iterator_category{ typedef typename Iterator::iterator_category type; }; // This portably gets the iterator_tag without partial template specialization template<class Iterator> struct get_iterator_category{ typedef typename conditional<is_pointer<Iterator>::value, pointer_iterator_category<Iterator>, class_iterator_category<Iterator> >::type cat; typedef typename cat::type iterator_category; }; } // namespace tokenizer_detail //=========================================================================== // The offset_separator class, which is a model of TokenizerFunction. // Offset breaks a string into tokens based on a range of offsets class offset_separator { private: std::vector<int> offsets_; unsigned int current_offset_; bool wrap_offsets_; bool return_partial_last_; public: template <typename Iter> offset_separator(Iter begin, Iter end, bool wrap_offsets = true, bool return_partial_last = true) : offsets_(begin,end), current_offset_(0), wrap_offsets_(wrap_offsets), return_partial_last_(return_partial_last) { } offset_separator() : offsets_(1,1), current_offset_(), wrap_offsets_(true), return_partial_last_(true) { } void reset() { current_offset_ = 0; } template <typename InputIterator, typename Token> bool operator()(InputIterator& next, InputIterator end, Token& tok) { typedef tokenizer_detail::assign_or_plus_equal< BOOST_DEDUCED_TYPENAME tokenizer_detail::get_iterator_category< InputIterator >::iterator_category > assigner; BOOST_ASSERT(!offsets_.empty()); assigner::clear(tok); InputIterator start(next); if (next == end) return false; if (current_offset_ == offsets_.size()) { if (wrap_offsets_) current_offset_=0; else return false; } int c = offsets_[current_offset_]; int i = 0; for (; i < c; ++i) { if (next == end)break; assigner::plus_equal(tok,*next++); } assigner::assign(start,next,tok); if (!return_partial_last_) if (i < (c-1) ) return false; ++current_offset_; return true; } }; //=========================================================================== // The char_separator class breaks a sequence of characters into // tokens based on the character delimiters (very much like bad old // strtok). A delimiter character can either be kept or dropped. A // kept delimiter shows up as an output token, whereas a dropped // delimiter does not. // This class replaces the char_delimiters_separator class. The // constructor for the char_delimiters_separator class was too // confusing and needed to be deprecated. However, because of the // default arguments to the constructor, adding the new constructor // would cause ambiguity, so instead I deprecated the whole class. // The implementation of the class was also simplified considerably. enum empty_token_policy { drop_empty_tokens, keep_empty_tokens }; // The out of the box GCC 2.95 on cygwin does not have a char_traits class. template <typename Char, typename Tr = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type > class char_separator { typedef tokenizer_detail::traits_extension<Tr> Traits; typedef std::basic_string<Char,Tr> string_type; public: explicit char_separator(const Char* dropped_delims, const Char* kept_delims = 0, empty_token_policy empty_tokens = drop_empty_tokens) : m_dropped_delims(dropped_delims), m_use_ispunct(false), m_use_isspace(false), m_empty_tokens(empty_tokens), m_output_done(false) { // Borland workaround if (kept_delims) m_kept_delims = kept_delims; } // use ispunct() for kept delimiters and isspace for dropped. explicit char_separator() : m_use_ispunct(true), m_use_isspace(true), m_empty_tokens(drop_empty_tokens), m_output_done(false) { } void reset() { } template <typename InputIterator, typename Token> bool operator()(InputIterator& next, InputIterator end, Token& tok) { typedef tokenizer_detail::assign_or_plus_equal< BOOST_DEDUCED_TYPENAME tokenizer_detail::get_iterator_category< InputIterator >::iterator_category > assigner; assigner::clear(tok); // skip past all dropped_delims if (m_empty_tokens == drop_empty_tokens) for (; next != end && is_dropped(*next); ++next) { } InputIterator start(next); if (m_empty_tokens == drop_empty_tokens) { if (next == end) return false; // if we are on a kept_delims move past it and stop if (is_kept(*next)) { assigner::plus_equal(tok,*next); ++next; } else // append all the non delim characters for (; next != end && !is_dropped(*next) && !is_kept(*next); ++next) assigner::plus_equal(tok,*next); } else { // m_empty_tokens == keep_empty_tokens // Handle empty token at the end if (next == end) { if (m_output_done == false) { m_output_done = true; assigner::assign(start,next,tok); return true; } else return false; } if (is_kept(*next)) { if (m_output_done == false) m_output_done = true; else { assigner::plus_equal(tok,*next); ++next; m_output_done = false; } } else if (m_output_done == false && is_dropped(*next)) { m_output_done = true; } else { if (is_dropped(*next)) start=++next; for (; next != end && !is_dropped(*next) && !is_kept(*next); ++next) assigner::plus_equal(tok,*next); m_output_done = true; } } assigner::assign(start,next,tok); return true; } private: string_type m_kept_delims; string_type m_dropped_delims; bool m_use_ispunct; bool m_use_isspace; empty_token_policy m_empty_tokens; bool m_output_done; bool is_kept(Char E) const { if (m_kept_delims.length()) return m_kept_delims.find(E) != string_type::npos; else if (m_use_ispunct) { return Traits::ispunct(E) != 0; } else return false; } bool is_dropped(Char E) const { if (m_dropped_delims.length()) return m_dropped_delims.find(E) != string_type::npos; else if (m_use_isspace) { return Traits::isspace(E) != 0; } else return false; } }; //=========================================================================== // The following class is DEPRECATED, use class char_separators instead. // // The char_delimiters_separator class, which is a model of // TokenizerFunction. char_delimiters_separator breaks a string // into tokens based on character delimiters. There are 2 types of // delimiters. returnable delimiters can be returned as // tokens. These are often punctuation. nonreturnable delimiters // cannot be returned as tokens. These are often whitespace // The out of the box GCC 2.95 on cygwin does not have a char_traits class. template <class Char, class Tr = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type > class char_delimiters_separator { private: typedef tokenizer_detail::traits_extension<Tr> Traits; typedef std::basic_string<Char,Tr> string_type; string_type returnable_; string_type nonreturnable_; bool return_delims_; bool no_ispunct_; bool no_isspace_; bool is_ret(Char E)const { if (returnable_.length()) return returnable_.find(E) != string_type::npos; else{ if (no_ispunct_) {return false;} else{ int r = Traits::ispunct(E); return r != 0; } } } bool is_nonret(Char E)const { if (nonreturnable_.length()) return nonreturnable_.find(E) != string_type::npos; else{ if (no_isspace_) {return false;} else{ int r = Traits::isspace(E); return r != 0; } } } public: explicit char_delimiters_separator(bool return_delims = false, const Char* returnable = 0, const Char* nonreturnable = 0) : returnable_(returnable ? returnable : string_type().c_str()), nonreturnable_(nonreturnable ? nonreturnable:string_type().c_str()), return_delims_(return_delims), no_ispunct_(returnable!=0), no_isspace_(nonreturnable!=0) { } void reset() { } public: template <typename InputIterator, typename Token> bool operator()(InputIterator& next, InputIterator end,Token& tok) { tok = Token(); // skip past all nonreturnable delims // skip past the returnable only if we are not returning delims for (;next!=end && ( is_nonret(*next) || (is_ret(*next) && !return_delims_ ) );++next) { } if (next == end) { return false; } // if we are to return delims and we are one a returnable one // move past it and stop if (is_ret(*next) && return_delims_) { tok+=*next; ++next; } else // append all the non delim characters for (;next!=end && !is_nonret(*next) && !is_ret(*next);++next) tok+=*next; return true; } }; } //namespace boost #endif