1 // Boost token_functions.hpp  ------------------------------------------------//
2 
3 // Copyright John R. Bandela 2001.
4 
5 // Distributed under the Boost Software License, Version 1.0. (See
6 // accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt)
8 
9 // See http://www.boost.org/libs/tokenizer/ for documentation.
10 
11 // Revision History:
12 // 01 Oct 2004   Joaquin M Lopez Munoz
13 //      Workaround for a problem with string::assign in msvc-stlport
14 // 06 Apr 2004   John Bandela
15 //      Fixed a bug involving using char_delimiter with a true input iterator
16 // 28 Nov 2003   Robert Zeh and John Bandela
17 //      Converted into "fast" functions that avoid using += when
18 //      the supplied iterator isn't an input_iterator; based on
19 //      some work done at Archelon and a version that was checked into
20 //      the boost CVS for a short period of time.
21 // 20 Feb 2002   John Maddock
22 //      Removed using namespace std declarations and added
23 //      workaround for BOOST_NO_STDC_NAMESPACE (the library
24 //      can be safely mixed with regex).
25 // 06 Feb 2002   Jeremy Siek
26 //      Added char_separator.
27 // 02 Feb 2002   Jeremy Siek
28 //      Removed tabs and a little cleanup.
29 
30 
31 #ifndef BOOST_TOKEN_FUNCTIONS_JRB120303_HPP_
32 #define BOOST_TOKEN_FUNCTIONS_JRB120303_HPP_
33 
34 #include <vector>
35 #include <stdexcept>
36 #include <string>
37 #include <cctype>
38 #include <algorithm> // for find_if
39 #include <boost/config.hpp>
40 #include <boost/assert.hpp>
41 #include <boost/type_traits/is_pointer.hpp>
42 #include <boost/detail/workaround.hpp>
43 #include <boost/mpl/if.hpp>
44 #include <boost/throw_exception.hpp>
45 #if !defined(BOOST_NO_CWCTYPE)
46 #include <cwctype>
47 #endif
48 
49 //
50 // the following must not be macros if we are to prefix them
51 // with std:: (they shouldn't be macros anyway...)
52 //
53 #ifdef ispunct
54 #  undef ispunct
55 #endif
56 #ifdef iswpunct
57 #  undef iswpunct
58 #endif
59 #ifdef isspace
60 #  undef isspace
61 #endif
62 #ifdef iswspace
63 #  undef iswspace
64 #endif
65 //
66 // fix namespace problems:
67 //
68 #ifdef BOOST_NO_STDC_NAMESPACE
69 namespace std{
70  using ::ispunct;
71  using ::isspace;
72 #if !defined(BOOST_NO_CWCTYPE)
73  using ::iswpunct;
74  using ::iswspace;
75 #endif
76 }
77 #endif
78 
79 namespace boost{
80   //===========================================================================
81   // The escaped_list_separator class. Which is a model of TokenizerFunction
82   // An escaped list is a super-set of what is commonly known as a comma
83   // separated value (csv) list.It is separated into fields by a comma or
84   // other character. If the delimiting character is inside quotes, then it is
85   // counted as a regular character.To allow for embedded quotes in a field,
86   // there can be escape sequences using the \ much like C.
87   // The role of the comma, the quotation mark, and the escape
88   // character (backslash \), can be assigned to other characters.
89 
90   struct escaped_list_error : public std::runtime_error{
escaped_list_errorboost::escaped_list_error91     escaped_list_error(const std::string& what_arg):std::runtime_error(what_arg) { }
92   };
93 
94 
95 // The out of the box GCC 2.95 on cygwin does not have a char_traits class.
96 // MSVC does not like the following typename
97   template <class Char,
98     class Traits = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type >
99   class escaped_list_separator {
100 
101   private:
102     typedef std::basic_string<Char,Traits> string_type;
103     struct char_eq {
104       Char e_;
char_eqboost::escaped_list_separator::char_eq105       char_eq(Char e):e_(e) { }
operator ()boost::escaped_list_separator::char_eq106       bool operator()(Char c) {
107         return Traits::eq(e_,c);
108       }
109     };
110     string_type  escape_;
111     string_type  c_;
112     string_type  quote_;
113     bool last_;
114 
is_escape(Char e)115     bool is_escape(Char e) {
116       char_eq f(e);
117       return std::find_if(escape_.begin(),escape_.end(),f)!=escape_.end();
118     }
is_c(Char e)119     bool is_c(Char e) {
120       char_eq f(e);
121       return std::find_if(c_.begin(),c_.end(),f)!=c_.end();
122     }
is_quote(Char e)123     bool is_quote(Char e) {
124       char_eq f(e);
125       return std::find_if(quote_.begin(),quote_.end(),f)!=quote_.end();
126     }
127     template <typename iterator, typename Token>
do_escape(iterator & next,iterator end,Token & tok)128     void do_escape(iterator& next,iterator end,Token& tok) {
129       if (++next == end)
130         BOOST_THROW_EXCEPTION(escaped_list_error(std::string("cannot end with escape")));
131       if (Traits::eq(*next,'n')) {
132         tok+='\n';
133         return;
134       }
135       else if (is_quote(*next)) {
136         tok+=*next;
137         return;
138       }
139       else if (is_c(*next)) {
140         tok+=*next;
141         return;
142       }
143       else if (is_escape(*next)) {
144         tok+=*next;
145         return;
146       }
147       else
148         BOOST_THROW_EXCEPTION(escaped_list_error(std::string("unknown escape sequence")));
149     }
150 
151     public:
152 
escaped_list_separator(Char e='\\\\',Char c=',',Char q='\\"')153     explicit escaped_list_separator(Char  e = '\\',
154                                     Char c = ',',Char  q = '\"')
155       : escape_(1,e), c_(1,c), quote_(1,q), last_(false) { }
156 
escaped_list_separator(string_type e,string_type c,string_type q)157     escaped_list_separator(string_type e, string_type c, string_type q)
158       : escape_(e), c_(c), quote_(q), last_(false) { }
159 
reset()160     void reset() {last_=false;}
161 
162     template <typename InputIterator, typename Token>
operator ()(InputIterator & next,InputIterator end,Token & tok)163     bool operator()(InputIterator& next,InputIterator end,Token& tok) {
164       bool bInQuote = false;
165       tok = Token();
166 
167       if (next == end) {
168         if (last_) {
169           last_ = false;
170           return true;
171         }
172         else
173           return false;
174       }
175       last_ = false;
176       for (;next != end;++next) {
177         if (is_escape(*next)) {
178           do_escape(next,end,tok);
179         }
180         else if (is_c(*next)) {
181           if (!bInQuote) {
182             // If we are not in quote, then we are done
183             ++next;
184             // The last character was a c, that means there is
185             // 1 more blank field
186             last_ = true;
187             return true;
188           }
189           else tok+=*next;
190         }
191         else if (is_quote(*next)) {
192           bInQuote=!bInQuote;
193         }
194         else {
195           tok += *next;
196         }
197       }
198       return true;
199     }
200   };
201 
202   //===========================================================================
203   // The classes here are used by offset_separator and char_separator to implement
204   // faster assigning of tokens using assign instead of +=
205 
206   namespace tokenizer_detail {
207   //===========================================================================
208   // Tokenizer was broken for wide character separators, at least on Windows, since
209   // CRT functions isspace etc only expect values in [0, 0xFF]. Debug build asserts
210   // if higher values are passed in. The traits extension class should take care of this.
211   // Assuming that the conditional will always get optimized out in the function
212   // implementations, argument types are not a problem since both forms of character classifiers
213   // expect an int.
214 
215 #if !defined(BOOST_NO_CWCTYPE)
216   template<typename traits, int N>
217   struct traits_extension_details : public traits {
218     typedef typename traits::char_type char_type;
isspaceboost::tokenizer_detail::traits_extension_details219     static bool isspace(char_type c)
220     {
221        return std::iswspace(c) != 0;
222     }
ispunctboost::tokenizer_detail::traits_extension_details223     static bool ispunct(char_type c)
224     {
225        return std::iswpunct(c) != 0;
226     }
227   };
228 
229   template<typename traits>
230   struct traits_extension_details<traits, 1> : public traits {
231     typedef typename traits::char_type char_type;
isspaceboost::tokenizer_detail::traits_extension_details232     static bool isspace(char_type c)
233     {
234        return std::isspace(c) != 0;
235     }
ispunctboost::tokenizer_detail::traits_extension_details236     static bool ispunct(char_type c)
237     {
238        return std::ispunct(c) != 0;
239     }
240   };
241 #endif
242 
243 
244   // In case there is no cwctype header, we implement the checks manually.
245   // We make use of the fact that the tested categories should fit in ASCII.
246   template<typename traits>
247   struct traits_extension : public traits {
248     typedef typename traits::char_type char_type;
isspaceboost::tokenizer_detail::traits_extension249     static bool isspace(char_type c)
250     {
251 #if !defined(BOOST_NO_CWCTYPE)
252       return traits_extension_details<traits, sizeof(char_type)>::isspace(c);
253 #else
254       return static_cast< unsigned >(c) <= 255 && std::isspace(c) != 0;
255 #endif
256     }
257 
ispunctboost::tokenizer_detail::traits_extension258     static bool ispunct(char_type c)
259     {
260 #if !defined(BOOST_NO_CWCTYPE)
261       return traits_extension_details<traits, sizeof(char_type)>::ispunct(c);
262 #else
263       return static_cast< unsigned >(c) <= 255 && std::ispunct(c) != 0;
264 #endif
265     }
266   };
267 
268   // The assign_or_plus_equal struct contains functions that implement
269   // assign, +=, and clearing based on the iterator type.  The
270   // generic case does nothing for plus_equal and clearing, while
271   // passing through the call for assign.
272   //
273   // When an input iterator is being used, the situation is reversed.
274   // The assign method does nothing, plus_equal invokes operator +=,
275   // and the clearing method sets the supplied token to the default
276   // token constructor's result.
277   //
278 
279   template<class IteratorTag>
280   struct assign_or_plus_equal {
281     template<class Iterator, class Token>
assignboost::tokenizer_detail::assign_or_plus_equal282     static void assign(Iterator b, Iterator e, Token &t) {
283       t.assign(b, e);
284     }
285 
286     template<class Token, class Value>
plus_equalboost::tokenizer_detail::assign_or_plus_equal287     static void plus_equal(Token &, const Value &) { }
288 
289     // If we are doing an assign, there is no need for the
290     // the clear.
291     //
292     template<class Token>
clearboost::tokenizer_detail::assign_or_plus_equal293     static void clear(Token &) { }
294   };
295 
296   template <>
297   struct assign_or_plus_equal<std::input_iterator_tag> {
298     template<class Iterator, class Token>
assignboost::tokenizer_detail::assign_or_plus_equal299     static void assign(Iterator , Iterator , Token &) { }
300     template<class Token, class Value>
plus_equalboost::tokenizer_detail::assign_or_plus_equal301     static void plus_equal(Token &t, const Value &v) {
302       t += v;
303     }
304     template<class Token>
clearboost::tokenizer_detail::assign_or_plus_equal305     static void clear(Token &t) {
306       t = Token();
307     }
308   };
309 
310 
311   template<class Iterator>
312   struct pointer_iterator_category{
313     typedef std::random_access_iterator_tag type;
314   };
315 
316 
317   template<class Iterator>
318   struct class_iterator_category{
319     typedef typename Iterator::iterator_category type;
320   };
321 
322 
323 
324   // This portably gets the iterator_tag without partial template specialization
325   template<class Iterator>
326     struct get_iterator_category{
327     typedef typename mpl::if_<is_pointer<Iterator>,
328       pointer_iterator_category<Iterator>,
329       class_iterator_category<Iterator>
330     >::type cat;
331 
332     typedef typename cat::type iterator_category;
333   };
334 
335 
336   } // namespace tokenizer_detail
337 
338 
339   //===========================================================================
340   // The offset_separator class, which is a model of TokenizerFunction.
341   // Offset breaks a string into tokens based on a range of offsets
342 
343   class offset_separator {
344   private:
345 
346     std::vector<int> offsets_;
347     unsigned int current_offset_;
348     bool wrap_offsets_;
349     bool return_partial_last_;
350 
351   public:
352     template <typename Iter>
offset_separator(Iter begin,Iter end,bool wrap_offsets=true,bool return_partial_last=true)353     offset_separator(Iter begin, Iter end, bool wrap_offsets = true,
354                      bool return_partial_last = true)
355       : offsets_(begin,end), current_offset_(0),
356         wrap_offsets_(wrap_offsets),
357         return_partial_last_(return_partial_last) { }
358 
offset_separator()359     offset_separator()
360       : offsets_(1,1), current_offset_(),
361         wrap_offsets_(true), return_partial_last_(true) { }
362 
reset()363     void reset() {
364       current_offset_ = 0;
365     }
366 
367     template <typename InputIterator, typename Token>
operator ()(InputIterator & next,InputIterator end,Token & tok)368     bool operator()(InputIterator& next, InputIterator end, Token& tok)
369     {
370       typedef tokenizer_detail::assign_or_plus_equal<
371         BOOST_DEDUCED_TYPENAME tokenizer_detail::get_iterator_category<
372           InputIterator
373         >::iterator_category
374       > assigner;
375 
376       BOOST_ASSERT(!offsets_.empty());
377 
378       assigner::clear(tok);
379       InputIterator start(next);
380 
381       if (next == end)
382         return false;
383 
384       if (current_offset_ == offsets_.size())
385       {
386         if (wrap_offsets_)
387           current_offset_=0;
388         else
389           return false;
390       }
391 
392       int c = offsets_[current_offset_];
393       int i = 0;
394       for (; i < c; ++i) {
395         if (next == end)break;
396         assigner::plus_equal(tok,*next++);
397       }
398       assigner::assign(start,next,tok);
399 
400       if (!return_partial_last_)
401         if (i < (c-1) )
402           return false;
403 
404       ++current_offset_;
405       return true;
406     }
407   };
408 
409 
410   //===========================================================================
411   // The char_separator class breaks a sequence of characters into
412   // tokens based on the character delimiters (very much like bad old
413   // strtok). A delimiter character can either be kept or dropped. A
414   // kept delimiter shows up as an output token, whereas a dropped
415   // delimiter does not.
416 
417   // This class replaces the char_delimiters_separator class. The
418   // constructor for the char_delimiters_separator class was too
419   // confusing and needed to be deprecated. However, because of the
420   // default arguments to the constructor, adding the new constructor
421   // would cause ambiguity, so instead I deprecated the whole class.
422   // The implementation of the class was also simplified considerably.
423 
424   enum empty_token_policy { drop_empty_tokens, keep_empty_tokens };
425 
426   // The out of the box GCC 2.95 on cygwin does not have a char_traits class.
427   template <typename Char,
428     typename Tr = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type >
429   class char_separator
430   {
431     typedef tokenizer_detail::traits_extension<Tr> Traits;
432     typedef std::basic_string<Char,Tr> string_type;
433   public:
434     explicit
char_separator(const Char * dropped_delims,const Char * kept_delims=0,empty_token_policy empty_tokens=drop_empty_tokens)435     char_separator(const Char* dropped_delims,
436                    const Char* kept_delims = 0,
437                    empty_token_policy empty_tokens = drop_empty_tokens)
438       : m_dropped_delims(dropped_delims),
439         m_use_ispunct(false),
440         m_use_isspace(false),
441         m_empty_tokens(empty_tokens),
442         m_output_done(false)
443     {
444       // Borland workaround
445       if (kept_delims)
446         m_kept_delims = kept_delims;
447     }
448 
449                 // use ispunct() for kept delimiters and isspace for dropped.
450     explicit
char_separator()451     char_separator()
452       : m_use_ispunct(true),
453         m_use_isspace(true),
454         m_empty_tokens(drop_empty_tokens),
455         m_output_done(false) { }
456 
reset()457     void reset() { }
458 
459     template <typename InputIterator, typename Token>
operator ()(InputIterator & next,InputIterator end,Token & tok)460     bool operator()(InputIterator& next, InputIterator end, Token& tok)
461     {
462       typedef tokenizer_detail::assign_or_plus_equal<
463         BOOST_DEDUCED_TYPENAME tokenizer_detail::get_iterator_category<
464           InputIterator
465         >::iterator_category
466       > assigner;
467 
468       assigner::clear(tok);
469 
470       // skip past all dropped_delims
471       if (m_empty_tokens == drop_empty_tokens)
472         for (; next != end  && is_dropped(*next); ++next)
473           { }
474 
475       InputIterator start(next);
476 
477       if (m_empty_tokens == drop_empty_tokens) {
478 
479         if (next == end)
480           return false;
481 
482 
483         // if we are on a kept_delims move past it and stop
484         if (is_kept(*next)) {
485           assigner::plus_equal(tok,*next);
486           ++next;
487         } else
488           // append all the non delim characters
489           for (; next != end && !is_dropped(*next) && !is_kept(*next); ++next)
490             assigner::plus_equal(tok,*next);
491       }
492       else { // m_empty_tokens == keep_empty_tokens
493 
494         // Handle empty token at the end
495         if (next == end)
496         {
497           if (m_output_done == false)
498           {
499             m_output_done = true;
500             assigner::assign(start,next,tok);
501             return true;
502           }
503           else
504             return false;
505         }
506 
507         if (is_kept(*next)) {
508           if (m_output_done == false)
509             m_output_done = true;
510           else {
511             assigner::plus_equal(tok,*next);
512             ++next;
513             m_output_done = false;
514           }
515         }
516         else if (m_output_done == false && is_dropped(*next)) {
517           m_output_done = true;
518         }
519         else {
520           if (is_dropped(*next))
521             start=++next;
522           for (; next != end && !is_dropped(*next) && !is_kept(*next); ++next)
523             assigner::plus_equal(tok,*next);
524           m_output_done = true;
525         }
526       }
527       assigner::assign(start,next,tok);
528       return true;
529     }
530 
531   private:
532     string_type m_kept_delims;
533     string_type m_dropped_delims;
534     bool m_use_ispunct;
535     bool m_use_isspace;
536     empty_token_policy m_empty_tokens;
537     bool m_output_done;
538 
is_kept(Char E) const539     bool is_kept(Char E) const
540     {
541       if (m_kept_delims.length())
542         return m_kept_delims.find(E) != string_type::npos;
543       else if (m_use_ispunct) {
544         return Traits::ispunct(E) != 0;
545       } else
546         return false;
547     }
is_dropped(Char E) const548     bool is_dropped(Char E) const
549     {
550       if (m_dropped_delims.length())
551         return m_dropped_delims.find(E) != string_type::npos;
552       else if (m_use_isspace) {
553         return Traits::isspace(E) != 0;
554       } else
555         return false;
556     }
557   };
558 
559   //===========================================================================
560   // The following class is DEPRECATED, use class char_separators instead.
561   //
562   // The char_delimiters_separator class, which is a model of
563   // TokenizerFunction.  char_delimiters_separator breaks a string
564   // into tokens based on character delimiters. There are 2 types of
565   // delimiters. returnable delimiters can be returned as
566   // tokens. These are often punctuation. nonreturnable delimiters
567   // cannot be returned as tokens. These are often whitespace
568 
569   // The out of the box GCC 2.95 on cygwin does not have a char_traits class.
570   template <class Char,
571     class Tr = BOOST_DEDUCED_TYPENAME std::basic_string<Char>::traits_type >
572   class char_delimiters_separator {
573   private:
574 
575     typedef tokenizer_detail::traits_extension<Tr> Traits;
576     typedef std::basic_string<Char,Tr> string_type;
577     string_type returnable_;
578     string_type nonreturnable_;
579     bool return_delims_;
580     bool no_ispunct_;
581     bool no_isspace_;
582 
is_ret(Char E) const583     bool is_ret(Char E)const
584     {
585       if (returnable_.length())
586         return  returnable_.find(E) != string_type::npos;
587       else{
588         if (no_ispunct_) {return false;}
589         else{
590           int r = Traits::ispunct(E);
591           return r != 0;
592         }
593       }
594     }
is_nonret(Char E) const595     bool is_nonret(Char E)const
596     {
597       if (nonreturnable_.length())
598         return  nonreturnable_.find(E) != string_type::npos;
599       else{
600         if (no_isspace_) {return false;}
601         else{
602           int r = Traits::isspace(E);
603           return r != 0;
604         }
605       }
606     }
607 
608   public:
char_delimiters_separator(bool return_delims=false,const Char * returnable=0,const Char * nonreturnable=0)609     explicit char_delimiters_separator(bool return_delims = false,
610                                        const Char* returnable = 0,
611                                        const Char* nonreturnable = 0)
612       : returnable_(returnable ? returnable : string_type().c_str()),
613         nonreturnable_(nonreturnable ? nonreturnable:string_type().c_str()),
614         return_delims_(return_delims), no_ispunct_(returnable!=0),
615         no_isspace_(nonreturnable!=0) { }
616 
reset()617     void reset() { }
618 
619   public:
620 
621      template <typename InputIterator, typename Token>
operator ()(InputIterator & next,InputIterator end,Token & tok)622      bool operator()(InputIterator& next, InputIterator end,Token& tok) {
623      tok = Token();
624 
625      // skip past all nonreturnable delims
626      // skip past the returnable only if we are not returning delims
627      for (;next!=end && ( is_nonret(*next) || (is_ret(*next)
628        && !return_delims_ ) );++next) { }
629 
630      if (next == end) {
631        return false;
632      }
633 
634      // if we are to return delims and we are one a returnable one
635      // move past it and stop
636      if (is_ret(*next) && return_delims_) {
637        tok+=*next;
638        ++next;
639      }
640      else
641        // append all the non delim characters
642        for (;next!=end && !is_nonret(*next) && !is_ret(*next);++next)
643          tok+=*next;
644 
645 
646      return true;
647    }
648   };
649 
650 
651 } //namespace boost
652 
653 #endif
654