PageRenderTime 95ms CodeModel.GetById 51ms app.highlight 38ms RepoModel.GetById 1ms app.codeStats 1ms

/Src/Dependencies/Boost/boost/format/parsing.hpp

http://hadesmem.googlecode.com/
C++ Header | 504 lines | 385 code | 59 blank | 60 comment | 84 complexity | 49614cd468e620ac36d248be538a9c11 MD5 | raw file
  1// ----------------------------------------------------------------------------
  2// parsing.hpp :  implementation of the parsing member functions
  3//                      ( parse, parse_printf_directive)
  4// ----------------------------------------------------------------------------
  5
  6//  Copyright Samuel Krempp 2003. Use, modification, and distribution are
  7//  subject to the Boost Software License, Version 1.0. (See accompanying
  8//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  9
 10// see http://www.boost.org/libs/format for library home page
 11
 12// ----------------------------------------------------------------------------
 13
 14#ifndef BOOST_FORMAT_PARSING_HPP
 15#define BOOST_FORMAT_PARSING_HPP
 16
 17
 18#include <boost/format/format_class.hpp>
 19#include <boost/format/exceptions.hpp>
 20#include <boost/throw_exception.hpp>
 21#include <boost/assert.hpp>
 22
 23
 24namespace boost {
 25namespace io {
 26namespace detail {
 27
 28#if defined(BOOST_NO_STD_LOCALE)
 29    // streams will be used for narrow / widen. but these methods are not const
 30    template<class T>
 31    T& const_or_not(const T& x) { 
 32        return const_cast<T&> (x);
 33    }
 34#else
 35    template<class T>
 36    const T& const_or_not(const T& x) { 
 37        return x;
 38    }
 39#endif
 40
 41    template<class Ch, class Facet> inline
 42    char wrap_narrow(const Facet& fac, Ch c, char deflt) {
 43        return const_or_not(fac).narrow(c, deflt);
 44    }
 45
 46    template<class Ch, class Facet> inline
 47    bool wrap_isdigit(const Facet& fac, Ch c) {
 48#if ! defined( BOOST_NO_LOCALE_ISDIGIT )
 49        return fac.is(std::ctype<Ch>::digit, c);
 50# else
 51        (void) fac;     // remove "unused parameter" warning
 52        using namespace std;
 53        return isdigit(c); 
 54#endif 
 55    }
 56 
 57    template<class Iter, class Facet> 
 58    Iter wrap_scan_notdigit(const Facet & fac, Iter beg, Iter end) {
 59        using namespace std;
 60        for( ; beg!=end && wrap_isdigit(fac, *beg); ++beg) ;
 61        return beg;
 62    }
 63
 64
 65    // Input : [start, last) iterators range and a
 66    //          a Facet to use its widen/narrow member function
 67    // Effects : read sequence and convert digits into integral n, of type Res
 68    // Returns : n
 69    template<class Res, class Iter, class Facet>
 70    Iter str2int (const Iter & start, const Iter & last, Res & res, 
 71                 const Facet& fac) 
 72    {
 73        using namespace std;
 74        Iter it;
 75        res=0;
 76        for(it=start; it != last && wrap_isdigit(fac, *it); ++it ) {
 77            char cur_ch = wrap_narrow(fac, *it, 0); // cant fail.
 78            res *= 10;
 79            res += cur_ch - '0'; // 22.2.1.1.2.13 of the C++ standard
 80        }
 81        return it;
 82    }
 83
 84    // skip printf's "asterisk-fields" directives in the format-string buf
 85    // Input : char string, with starting index *pos_p
 86    //         a Facet merely to use its widen/narrow member function
 87    // Effects : advance *pos_p by skipping printf's asterisk fields.
 88    // Returns : nothing
 89    template<class Iter, class Facet>
 90    Iter skip_asterisk(Iter start, Iter last, const Facet& fac) 
 91    {
 92        using namespace std;
 93        ++ start;
 94        start = wrap_scan_notdigit(fac, start, last);
 95        if(start!=last && *start== const_or_not(fac).widen( '$') )
 96            ++start;
 97        return start;
 98    }
 99
100
101    // auxiliary func called by parse_printf_directive
102    // for centralising error handling
103    // it either throws if user sets the corresponding flag, or does nothing.
104    inline void maybe_throw_exception(unsigned char exceptions, 
105                                      std::size_t pos, std::size_t size)
106    {
107        if(exceptions & io::bad_format_string_bit)
108            boost::throw_exception(io::bad_format_string(pos, size) );
109    }
110    
111
112    // Input: the position of a printf-directive in the format-string
113    //    a basic_ios& merely to use its widen/narrow member function
114    //    a bitset'exceptions' telling whether to throw exceptions on errors.
115    // Returns:
116    //  true if parse succeeded (ignore some errors if exceptions disabled)
117    //  false if it failed so bad that the directive should be printed verbatim
118    // Effects:
119    //  start is incremented so that *start is the first char after
120    //     this directive
121    //  *fpar is set with the parameters read in the directive
122    template<class Ch, class Tr, class Alloc, class Iter, class Facet>
123    bool parse_printf_directive(Iter & start, const Iter& last, 
124                                detail::format_item<Ch, Tr, Alloc> * fpar,
125                                const Facet& fac,
126                                std::size_t offset, unsigned char exceptions)
127    {
128        typedef typename basic_format<Ch, Tr, Alloc>::format_item_t format_item_t;
129
130        fpar->argN_ = format_item_t::argN_no_posit;  // if no positional-directive
131        bool precision_set = false;
132        bool in_brackets=false;
133        Iter start0 = start;
134        std::size_t fstring_size = last-start0+offset;
135
136        if(start>= last) { // empty directive : this is a trailing %
137                maybe_throw_exception(exceptions, start-start0 + offset, fstring_size);
138                return false;
139        }          
140          
141        if(*start== const_or_not(fac).widen( '|')) {
142            in_brackets=true;
143            if( ++start >= last ) {
144                maybe_throw_exception(exceptions, start-start0 + offset, fstring_size);
145                return false;
146            }
147        }
148
149        // the flag '0' would be picked as a digit for argument order, but here it's a flag :
150        if(*start== const_or_not(fac).widen( '0')) 
151            goto parse_flags;
152
153        // handle argument order (%2$d)  or possibly width specification: %2d
154        if(wrap_isdigit(fac, *start)) {
155            int n;
156            start = str2int(start, last, n, fac);
157            if( start >= last ) {
158                maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
159                return false;
160            }
161            
162            // %N% case : this is already the end of the directive
163            if( *start ==  const_or_not(fac).widen( '%') ) {
164                fpar->argN_ = n-1;
165                ++start;
166                if( in_brackets) 
167                    maybe_throw_exception(exceptions, start-start0+offset, fstring_size); 
168                // but don't return.  maybe "%" was used in lieu of '$', so we go on.
169                else
170                    return true;
171            }
172
173            if ( *start== const_or_not(fac).widen( '$') ) {
174                fpar->argN_ = n-1;
175                ++start;
176            } 
177            else {
178                // non-positionnal directive
179                fpar->fmtstate_.width_ = n;
180                fpar->argN_  = format_item_t::argN_no_posit;
181                goto parse_precision;
182            }
183        }
184    
185      parse_flags: 
186        // handle flags
187        while ( start != last) { // as long as char is one of + - = _ # 0 l h   or ' '
188            // misc switches
189            switch ( wrap_narrow(fac, *start, 0)) {
190            case '\'' : break; // no effect yet. (painful to implement)
191            case 'l':
192            case 'h':  // short/long modifier : for printf-comaptibility (no action needed)
193                break;
194            case '-':
195                fpar->fmtstate_.flags_ |= std::ios_base::left;
196                break;
197            case '=':
198                fpar->pad_scheme_ |= format_item_t::centered;
199                break;
200            case '_':
201                fpar->fmtstate_.flags_ |= std::ios_base::internal;
202                break;
203            case ' ':
204                fpar->pad_scheme_ |= format_item_t::spacepad;
205                break;
206            case '+':
207                fpar->fmtstate_.flags_ |= std::ios_base::showpos;
208                break;
209            case '0':
210                fpar->pad_scheme_ |= format_item_t::zeropad;
211                // need to know alignment before really setting flags,
212                // so just add 'zeropad' flag for now, it will be processed later.
213                break;
214            case '#':
215                fpar->fmtstate_.flags_ |= std::ios_base::showpoint | std::ios_base::showbase;
216                break;
217            default:
218                goto parse_width;
219            }
220            ++start;
221        } // loop on flag.
222
223        if( start>=last) {
224            maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
225            return true; 
226        }
227      parse_width:
228        // handle width spec
229        // first skip 'asterisk fields' :  *, or *N$
230        if(*start == const_or_not(fac).widen( '*') )
231            start = skip_asterisk(start, last, fac); 
232        if(start!=last && wrap_isdigit(fac, *start))
233            start = str2int(start, last, fpar->fmtstate_.width_, fac);
234
235      parse_precision:
236        if( start>= last) { 
237            maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
238            return true;
239        }
240        // handle precision spec
241        if (*start== const_or_not(fac).widen( '.')) {
242            ++start;
243            if(start != last && *start == const_or_not(fac).widen( '*') )
244                start = skip_asterisk(start, last, fac); 
245            if(start != last && wrap_isdigit(fac, *start)) {
246                start = str2int(start, last, fpar->fmtstate_.precision_, fac);
247                precision_set = true;
248            }
249            else
250                fpar->fmtstate_.precision_ =0;
251        }
252    
253        // handle  formatting-type flags :
254        while( start != last && ( *start== const_or_not(fac).widen( 'l') 
255                                  || *start== const_or_not(fac).widen( 'L') 
256                                  || *start== const_or_not(fac).widen( 'h')) )
257            ++start;
258        if( start>=last) {
259            maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
260            return true;
261        }
262
263        if( in_brackets && *start== const_or_not(fac).widen( '|') ) {
264            ++start;
265            return true;
266        }
267        switch ( wrap_narrow(fac, *start, 0) ) {
268        case 'X':
269            fpar->fmtstate_.flags_ |= std::ios_base::uppercase;
270        case 'p': // pointer => set hex.
271        case 'x':
272            fpar->fmtstate_.flags_ &= ~std::ios_base::basefield;
273            fpar->fmtstate_.flags_ |= std::ios_base::hex;
274            break;
275
276        case 'o':
277            fpar->fmtstate_.flags_ &= ~std::ios_base::basefield;
278            fpar->fmtstate_.flags_ |=  std::ios_base::oct;
279            break;
280
281        case 'E':
282            fpar->fmtstate_.flags_ |=  std::ios_base::uppercase;
283        case 'e':
284            fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield;
285            fpar->fmtstate_.flags_ |=  std::ios_base::scientific;
286
287            fpar->fmtstate_.flags_ &= ~std::ios_base::basefield;
288            fpar->fmtstate_.flags_ |=  std::ios_base::dec;
289            break;
290      
291        case 'f':
292            fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield;
293            fpar->fmtstate_.flags_ |=  std::ios_base::fixed;
294        case 'u':
295        case 'd':
296        case 'i':
297            fpar->fmtstate_.flags_ &= ~std::ios_base::basefield;
298            fpar->fmtstate_.flags_ |=  std::ios_base::dec;
299            break;
300
301        case 'T':
302            ++start;
303            if( start >= last)
304                maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
305            else
306                fpar->fmtstate_.fill_ = *start;
307            fpar->pad_scheme_ |= format_item_t::tabulation;
308            fpar->argN_ = format_item_t::argN_tabulation; 
309            break;
310        case 't': 
311            fpar->fmtstate_.fill_ = const_or_not(fac).widen( ' ');
312            fpar->pad_scheme_ |= format_item_t::tabulation;
313            fpar->argN_ = format_item_t::argN_tabulation; 
314            break;
315
316        case 'G':
317            fpar->fmtstate_.flags_ |= std::ios_base::uppercase;
318            break;
319        case 'g': // 'g' conversion is default for floats.
320            fpar->fmtstate_.flags_ &= ~std::ios_base::basefield;
321            fpar->fmtstate_.flags_ |=  std::ios_base::dec;
322
323            // CLEAR all floatield flags, so stream will CHOOSE
324            fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield; 
325            break;
326
327        case 'C':
328        case 'c': 
329            fpar->truncate_ = 1;
330            break;
331        case 'S':
332        case 's': 
333            if(precision_set) // handle truncation manually, with own parameter.
334                fpar->truncate_ = fpar->fmtstate_.precision_;
335            fpar->fmtstate_.precision_ = 6; // default stream precision.
336            break;
337        case 'n' :  
338            fpar->argN_ = format_item_t::argN_ignored;
339            break;
340        default: 
341            maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
342        }
343        ++start;
344
345        if( in_brackets ) {
346            if( start != last && *start== const_or_not(fac).widen( '|') ) {
347                ++start;
348                return true;
349            }
350            else  maybe_throw_exception(exceptions, start-start0+offset, fstring_size);
351        }
352        return true;
353    }
354    // -end parse_printf_directive()
355
356    template<class String, class Facet>
357    int upper_bound_from_fstring(const String& buf, 
358                                 const typename String::value_type arg_mark,
359                                 const Facet& fac, 
360                                 unsigned char exceptions) 
361    {
362        // quick-parsing of the format-string to count arguments mark (arg_mark, '%')
363        // returns : upper bound on the number of format items in the format strings
364        using namespace boost::io;
365        typename String::size_type i1=0;
366        int num_items=0;
367        while( (i1=buf.find(arg_mark,i1)) != String::npos ) {
368            if( i1+1 >= buf.size() ) {
369                if(exceptions & bad_format_string_bit)
370                    boost::throw_exception(bad_format_string(i1, buf.size() )); // must not end in ".. %"
371                else {
372                  ++num_items;
373                  break;
374                }
375            }
376            if(buf[i1+1] == buf[i1] ) {// escaped "%%"
377                i1+=2; continue; 
378            }
379
380            ++i1;
381            // in case of %N% directives, dont count it double (wastes allocations..) :
382            i1 = detail::wrap_scan_notdigit(fac, buf.begin()+i1, buf.end()) - buf.begin();
383            if( i1 < buf.size() && buf[i1] == arg_mark )
384                ++i1;
385            ++num_items;
386        }
387        return num_items;
388    }
389    template<class String> inline
390    void append_string(String& dst, const String& src, 
391                       const typename String::size_type beg, 
392                       const typename String::size_type end) {
393#if !defined(BOOST_NO_STRING_APPEND)
394        dst.append(src.begin()+beg, src.begin()+end);
395#else
396        dst += src.substr(beg, end-beg);
397#endif
398    }
399
400} // detail namespace
401} // io namespace
402
403
404
405// -----------------------------------------------
406//  format :: parse(..)
407
408    template<class Ch, class Tr, class Alloc>
409    basic_format<Ch, Tr, Alloc>& basic_format<Ch, Tr, Alloc>:: 
410    parse (const string_type& buf) {
411        // parse the format-string 
412        using namespace std;
413#if !defined(BOOST_NO_STD_LOCALE)
414        const std::ctype<Ch> & fac = BOOST_USE_FACET( std::ctype<Ch>, getloc());
415#else
416        io::basic_oaltstringstream<Ch, Tr, Alloc> fac; 
417        //has widen and narrow even on compilers without locale
418#endif
419
420        const Ch arg_mark = io::detail::const_or_not(fac).widen( '%');
421        bool ordered_args=true; 
422        int max_argN=-1;
423
424        // A: find upper_bound on num_items and allocates arrays
425        int num_items = io::detail::upper_bound_from_fstring(buf, arg_mark, fac, exceptions());
426        make_or_reuse_data(num_items);
427
428        // B: Now the real parsing of the format string :
429        num_items=0;
430        typename string_type::size_type i0=0, i1=0;
431        typename string_type::const_iterator it;
432        bool special_things=false;
433        int cur_item=0;
434        while( (i1=buf.find(arg_mark,i1)) != string_type::npos ) {
435            string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_;
436            if( buf[i1+1] == buf[i1] ) { // escaped mark, '%%' 
437                io::detail::append_string(piece, buf, i0, i1+1);
438                i1+=2; i0=i1;
439                continue; 
440            }
441            BOOST_ASSERT(  static_cast<unsigned int>(cur_item) < items_.size() || cur_item==0);
442
443            if(i1!=i0) {
444                io::detail::append_string(piece, buf, i0, i1);
445                i0=i1;
446            }
447            ++i1;
448            it = buf.begin()+i1;
449            bool parse_ok = io::detail::parse_printf_directive(
450                it, buf.end(), &items_[cur_item], fac, i1, exceptions());
451            i1 = it - buf.begin();
452            if( ! parse_ok ) // the directive will be printed verbatim
453                continue; 
454            i0=i1;
455            items_[cur_item].compute_states(); // process complex options, like zeropad, into params
456
457            int argN=items_[cur_item].argN_;
458            if(argN == format_item_t::argN_ignored)
459                continue;
460            if(argN ==format_item_t::argN_no_posit)
461                ordered_args=false;
462            else if(argN == format_item_t::argN_tabulation) special_things=true;
463            else if(argN > max_argN) max_argN = argN;
464            ++num_items;
465            ++cur_item;
466        } // loop on %'s
467        BOOST_ASSERT(cur_item == num_items);
468    
469        // store the final piece of string
470        {
471            string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_;
472            io::detail::append_string(piece, buf, i0, buf.size());
473        }
474    
475        if( !ordered_args) {
476            if(max_argN >= 0 ) {  // dont mix positional with non-positionnal directives
477                if(exceptions() & io::bad_format_string_bit)
478                    boost::throw_exception(io::bad_format_string(max_argN, 0));
479                // else do nothing. => positionnal arguments are processed as non-positionnal
480            }
481            // set things like it would have been with positional directives :
482            int non_ordered_items = 0;
483            for(int i=0; i< num_items; ++i)
484                if(items_[i].argN_ == format_item_t::argN_no_posit) {
485                    items_[i].argN_ = non_ordered_items;
486                    ++non_ordered_items;
487                }
488            max_argN = non_ordered_items-1;
489        }
490    
491        // C: set some member data :
492        items_.resize(num_items, format_item_t(io::detail::const_or_not(fac).widen( ' ')) );
493
494        if(special_things) style_ |= special_needs;
495        num_args_ = max_argN + 1;
496        if(ordered_args) style_ |=  ordered;
497        else style_ &= ~ordered;
498        return *this;
499    }
500
501} // namespace boost
502
503
504#endif //  BOOST_FORMAT_PARSING_HPP