| // ---------------------------------------------------------------------------- | |
| // parsing.hpp : implementation of the parsing member functions | |
| // ( parse, parse_printf_directive) | |
| // ---------------------------------------------------------------------------- | |
| // Copyright Samuel Krempp 2003. Use, modification, and distribution are | |
| // subject to 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/format for library home page | |
| // ---------------------------------------------------------------------------- | |
| #ifndef BOOST_FORMAT_PARSING_HPP | |
| #define BOOST_FORMAT_PARSING_HPP | |
| #include <boost/format/format_class.hpp> | |
| #include <boost/format/exceptions.hpp> | |
| #include <boost/throw_exception.hpp> | |
| #include <boost/assert.hpp> | |
| namespace boost { | |
| namespace io { | |
| namespace detail { | |
| #if defined(BOOST_NO_STD_LOCALE) | |
| // streams will be used for narrow / widen. but these methods are not const | |
| template<class T> | |
| T& const_or_not(const T& x) { | |
| return const_cast<T&> (x); | |
| } | |
| #else | |
| template<class T> | |
| const T& const_or_not(const T& x) { | |
| return x; | |
| } | |
| #endif | |
| template<class Ch, class Facet> inline | |
| char wrap_narrow(const Facet& fac, Ch c, char deflt) { | |
| return const_or_not(fac).narrow(c, deflt); | |
| } | |
| template<class Ch, class Facet> inline | |
| bool wrap_isdigit(const Facet& fac, Ch c) { | |
| #if ! defined( BOOST_NO_LOCALE_ISDIGIT ) | |
| return fac.is(std::ctype<Ch>::digit, c); | |
| # else | |
| (void) fac; // remove "unused parameter" warning | |
| using namespace std; | |
| return isdigit(c); | |
| #endif | |
| } | |
| template<class Iter, class Facet> | |
| Iter wrap_scan_notdigit(const Facet & fac, Iter beg, Iter end) { | |
| using namespace std; | |
| for( ; beg!=end && wrap_isdigit(fac, *beg); ++beg) ; | |
| return beg; | |
| } | |
| // Input : [start, last) iterators range and a | |
| // a Facet to use its widen/narrow member function | |
| // Effects : read sequence and convert digits into integral n, of type Res | |
| // Returns : n | |
| template<class Res, class Iter, class Facet> | |
| Iter str2int (const Iter & start, const Iter & last, Res & res, | |
| const Facet& fac) | |
| { | |
| using namespace std; | |
| Iter it; | |
| res=0; | |
| for(it=start; it != last && wrap_isdigit(fac, *it); ++it ) { | |
| char cur_ch = wrap_narrow(fac, *it, 0); // cant fail. | |
| res *= 10; | |
| res += cur_ch - '0'; // 22.2.1.1.2.13 of the C++ standard | |
| } | |
| return it; | |
| } | |
| // skip printf's "asterisk-fields" directives in the format-string buf | |
| // Input : char string, with starting index *pos_p | |
| // a Facet merely to use its widen/narrow member function | |
| // Effects : advance *pos_p by skipping printf's asterisk fields. | |
| // Returns : nothing | |
| template<class Iter, class Facet> | |
| Iter skip_asterisk(Iter start, Iter last, const Facet& fac) | |
| { | |
| using namespace std; | |
| ++ start; | |
| start = wrap_scan_notdigit(fac, start, last); | |
| if(start!=last && *start== const_or_not(fac).widen( '$') ) | |
| ++start; | |
| return start; | |
| } | |
| // auxiliary func called by parse_printf_directive | |
| // for centralising error handling | |
| // it either throws if user sets the corresponding flag, or does nothing. | |
| inline void maybe_throw_exception(unsigned char exceptions, | |
| std::size_t pos, std::size_t size) | |
| { | |
| if(exceptions & io::bad_format_string_bit) | |
| boost::throw_exception(io::bad_format_string(pos, size) ); | |
| } | |
| // Input: the position of a printf-directive in the format-string | |
| // a basic_ios& merely to use its widen/narrow member function | |
| // a bitset'exceptions' telling whether to throw exceptions on errors. | |
| // Returns: | |
| // true if parse succeeded (ignore some errors if exceptions disabled) | |
| // false if it failed so bad that the directive should be printed verbatim | |
| // Effects: | |
| // start is incremented so that *start is the first char after | |
| // this directive | |
| // *fpar is set with the parameters read in the directive | |
| template<class Ch, class Tr, class Alloc, class Iter, class Facet> | |
| bool parse_printf_directive(Iter & start, const Iter& last, | |
| detail::format_item<Ch, Tr, Alloc> * fpar, | |
| const Facet& fac, | |
| std::size_t offset, unsigned char exceptions) | |
| { | |
| typedef typename basic_format<Ch, Tr, Alloc>::format_item_t format_item_t; | |
| fpar->argN_ = format_item_t::argN_no_posit; // if no positional-directive | |
| bool precision_set = false; | |
| bool in_brackets=false; | |
| Iter start0 = start; | |
| std::size_t fstring_size = last-start0+offset; | |
| if(start>= last) { // empty directive : this is a trailing % | |
| maybe_throw_exception(exceptions, start-start0 + offset, fstring_size); | |
| return false; | |
| } | |
| if(*start== const_or_not(fac).widen( '|')) { | |
| in_brackets=true; | |
| if( ++start >= last ) { | |
| maybe_throw_exception(exceptions, start-start0 + offset, fstring_size); | |
| return false; | |
| } | |
| } | |
| // the flag '0' would be picked as a digit for argument order, but here it's a flag : | |
| if(*start== const_or_not(fac).widen( '0')) | |
| goto parse_flags; | |
| // handle argument order (%2$d) or possibly width specification: %2d | |
| if(wrap_isdigit(fac, *start)) { | |
| int n; | |
| start = str2int(start, last, n, fac); | |
| if( start >= last ) { | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| return false; | |
| } | |
| // %N% case : this is already the end of the directive | |
| if( *start == const_or_not(fac).widen( '%') ) { | |
| fpar->argN_ = n-1; | |
| ++start; | |
| if( in_brackets) | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| // but don't return. maybe "%" was used in lieu of '$', so we go on. | |
| else | |
| return true; | |
| } | |
| if ( *start== const_or_not(fac).widen( '$') ) { | |
| fpar->argN_ = n-1; | |
| ++start; | |
| } | |
| else { | |
| // non-positionnal directive | |
| fpar->fmtstate_.width_ = n; | |
| fpar->argN_ = format_item_t::argN_no_posit; | |
| goto parse_precision; | |
| } | |
| } | |
| parse_flags: | |
| // handle flags | |
| while ( start != last) { // as long as char is one of + - = _ # 0 l h or ' ' | |
| // misc switches | |
| switch ( wrap_narrow(fac, *start, 0)) { | |
| case '\'' : break; // no effect yet. (painful to implement) | |
| case 'l': | |
| case 'h': // short/long modifier : for printf-comaptibility (no action needed) | |
| break; | |
| case '-': | |
| fpar->fmtstate_.flags_ |= std::ios_base::left; | |
| break; | |
| case '=': | |
| fpar->pad_scheme_ |= format_item_t::centered; | |
| break; | |
| case '_': | |
| fpar->fmtstate_.flags_ |= std::ios_base::internal; | |
| break; | |
| case ' ': | |
| fpar->pad_scheme_ |= format_item_t::spacepad; | |
| break; | |
| case '+': | |
| fpar->fmtstate_.flags_ |= std::ios_base::showpos; | |
| break; | |
| case '0': | |
| fpar->pad_scheme_ |= format_item_t::zeropad; | |
| // need to know alignment before really setting flags, | |
| // so just add 'zeropad' flag for now, it will be processed later. | |
| break; | |
| case '#': | |
| fpar->fmtstate_.flags_ |= std::ios_base::showpoint | std::ios_base::showbase; | |
| break; | |
| default: | |
| goto parse_width; | |
| } | |
| ++start; | |
| } // loop on flag. | |
| if( start>=last) { | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| return true; | |
| } | |
| parse_width: | |
| // handle width spec | |
| // first skip 'asterisk fields' : *, or *N$ | |
| if(*start == const_or_not(fac).widen( '*') ) | |
| start = skip_asterisk(start, last, fac); | |
| if(start!=last && wrap_isdigit(fac, *start)) | |
| start = str2int(start, last, fpar->fmtstate_.width_, fac); | |
| parse_precision: | |
| if( start>= last) { | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| return true; | |
| } | |
| // handle precision spec | |
| if (*start== const_or_not(fac).widen( '.')) { | |
| ++start; | |
| if(start != last && *start == const_or_not(fac).widen( '*') ) | |
| start = skip_asterisk(start, last, fac); | |
| if(start != last && wrap_isdigit(fac, *start)) { | |
| start = str2int(start, last, fpar->fmtstate_.precision_, fac); | |
| precision_set = true; | |
| } | |
| else | |
| fpar->fmtstate_.precision_ =0; | |
| } | |
| // handle formatting-type flags : | |
| while( start != last && ( *start== const_or_not(fac).widen( 'l') | |
| || *start== const_or_not(fac).widen( 'L') | |
| || *start== const_or_not(fac).widen( 'h')) ) | |
| ++start; | |
| if( start>=last) { | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| return true; | |
| } | |
| if( in_brackets && *start== const_or_not(fac).widen( '|') ) { | |
| ++start; | |
| return true; | |
| } | |
| switch ( wrap_narrow(fac, *start, 0) ) { | |
| case 'X': | |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; | |
| case 'p': // pointer => set hex. | |
| case 'x': | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::hex; | |
| break; | |
| case 'o': | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::oct; | |
| break; | |
| case 'E': | |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; | |
| case 'e': | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::scientific; | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::dec; | |
| break; | |
| case 'f': | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::fixed; | |
| case 'u': | |
| case 'd': | |
| case 'i': | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::dec; | |
| break; | |
| case 'T': | |
| ++start; | |
| if( start >= last) | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| else | |
| fpar->fmtstate_.fill_ = *start; | |
| fpar->pad_scheme_ |= format_item_t::tabulation; | |
| fpar->argN_ = format_item_t::argN_tabulation; | |
| break; | |
| case 't': | |
| fpar->fmtstate_.fill_ = const_or_not(fac).widen( ' '); | |
| fpar->pad_scheme_ |= format_item_t::tabulation; | |
| fpar->argN_ = format_item_t::argN_tabulation; | |
| break; | |
| case 'G': | |
| fpar->fmtstate_.flags_ |= std::ios_base::uppercase; | |
| break; | |
| case 'g': // 'g' conversion is default for floats. | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::basefield; | |
| fpar->fmtstate_.flags_ |= std::ios_base::dec; | |
| // CLEAR all floatield flags, so stream will CHOOSE | |
| fpar->fmtstate_.flags_ &= ~std::ios_base::floatfield; | |
| break; | |
| case 'C': | |
| case 'c': | |
| fpar->truncate_ = 1; | |
| break; | |
| case 'S': | |
| case 's': | |
| if(precision_set) // handle truncation manually, with own parameter. | |
| fpar->truncate_ = fpar->fmtstate_.precision_; | |
| fpar->fmtstate_.precision_ = 6; // default stream precision. | |
| break; | |
| case 'n' : | |
| fpar->argN_ = format_item_t::argN_ignored; | |
| break; | |
| default: | |
| maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| } | |
| ++start; | |
| if( in_brackets ) { | |
| if( start != last && *start== const_or_not(fac).widen( '|') ) { | |
| ++start; | |
| return true; | |
| } | |
| else maybe_throw_exception(exceptions, start-start0+offset, fstring_size); | |
| } | |
| return true; | |
| } | |
| // -end parse_printf_directive() | |
| template<class String, class Facet> | |
| int upper_bound_from_fstring(const String& buf, | |
| const typename String::value_type arg_mark, | |
| const Facet& fac, | |
| unsigned char exceptions) | |
| { | |
| // quick-parsing of the format-string to count arguments mark (arg_mark, '%') | |
| // returns : upper bound on the number of format items in the format strings | |
| using namespace boost::io; | |
| typename String::size_type i1=0; | |
| int num_items=0; | |
| while( (i1=buf.find(arg_mark,i1)) != String::npos ) { | |
| if( i1+1 >= buf.size() ) { | |
| if(exceptions & bad_format_string_bit) | |
| boost::throw_exception(bad_format_string(i1, buf.size() )); // must not end in ".. %" | |
| else { | |
| ++num_items; | |
| break; | |
| } | |
| } | |
| if(buf[i1+1] == buf[i1] ) {// escaped "%%" | |
| i1+=2; continue; | |
| } | |
| ++i1; | |
| // in case of %N% directives, dont count it double (wastes allocations..) : | |
| i1 = detail::wrap_scan_notdigit(fac, buf.begin()+i1, buf.end()) - buf.begin(); | |
| if( i1 < buf.size() && buf[i1] == arg_mark ) | |
| ++i1; | |
| ++num_items; | |
| } | |
| return num_items; | |
| } | |
| template<class String> inline | |
| void append_string(String& dst, const String& src, | |
| const typename String::size_type beg, | |
| const typename String::size_type end) { | |
| #if !defined(BOOST_NO_STRING_APPEND) | |
| dst.append(src.begin()+beg, src.begin()+end); | |
| #else | |
| dst += src.substr(beg, end-beg); | |
| #endif | |
| } | |
| } // detail namespace | |
| } // io namespace | |
| // ----------------------------------------------- | |
| // format :: parse(..) | |
| template<class Ch, class Tr, class Alloc> | |
| basic_format<Ch, Tr, Alloc>& basic_format<Ch, Tr, Alloc>:: | |
| parse (const string_type& buf) { | |
| // parse the format-string | |
| using namespace std; | |
| #if !defined(BOOST_NO_STD_LOCALE) | |
| const std::ctype<Ch> & fac = BOOST_USE_FACET( std::ctype<Ch>, getloc()); | |
| #else | |
| io::basic_oaltstringstream<Ch, Tr, Alloc> fac; | |
| //has widen and narrow even on compilers without locale | |
| #endif | |
| const Ch arg_mark = io::detail::const_or_not(fac).widen( '%'); | |
| bool ordered_args=true; | |
| int max_argN=-1; | |
| // A: find upper_bound on num_items and allocates arrays | |
| int num_items = io::detail::upper_bound_from_fstring(buf, arg_mark, fac, exceptions()); | |
| make_or_reuse_data(num_items); | |
| // B: Now the real parsing of the format string : | |
| num_items=0; | |
| typename string_type::size_type i0=0, i1=0; | |
| typename string_type::const_iterator it; | |
| bool special_things=false; | |
| int cur_item=0; | |
| while( (i1=buf.find(arg_mark,i1)) != string_type::npos ) { | |
| string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_; | |
| if( buf[i1+1] == buf[i1] ) { // escaped mark, '%%' | |
| io::detail::append_string(piece, buf, i0, i1+1); | |
| i1+=2; i0=i1; | |
| continue; | |
| } | |
| BOOST_ASSERT( static_cast<unsigned int>(cur_item) < items_.size() || cur_item==0); | |
| if(i1!=i0) { | |
| io::detail::append_string(piece, buf, i0, i1); | |
| i0=i1; | |
| } | |
| ++i1; | |
| it = buf.begin()+i1; | |
| bool parse_ok = io::detail::parse_printf_directive( | |
| it, buf.end(), &items_[cur_item], fac, i1, exceptions()); | |
| i1 = it - buf.begin(); | |
| if( ! parse_ok ) // the directive will be printed verbatim | |
| continue; | |
| i0=i1; | |
| items_[cur_item].compute_states(); // process complex options, like zeropad, into params | |
| int argN=items_[cur_item].argN_; | |
| if(argN == format_item_t::argN_ignored) | |
| continue; | |
| if(argN ==format_item_t::argN_no_posit) | |
| ordered_args=false; | |
| else if(argN == format_item_t::argN_tabulation) special_things=true; | |
| else if(argN > max_argN) max_argN = argN; | |
| ++num_items; | |
| ++cur_item; | |
| } // loop on %'s | |
| BOOST_ASSERT(cur_item == num_items); | |
| // store the final piece of string | |
| { | |
| string_type & piece = (cur_item==0) ? prefix_ : items_[cur_item-1].appendix_; | |
| io::detail::append_string(piece, buf, i0, buf.size()); | |
| } | |
| if( !ordered_args) { | |
| if(max_argN >= 0 ) { // dont mix positional with non-positionnal directives | |
| if(exceptions() & io::bad_format_string_bit) | |
| boost::throw_exception(io::bad_format_string(max_argN, 0)); | |
| // else do nothing. => positionnal arguments are processed as non-positionnal | |
| } | |
| // set things like it would have been with positional directives : | |
| int non_ordered_items = 0; | |
| for(int i=0; i< num_items; ++i) | |
| if(items_[i].argN_ == format_item_t::argN_no_posit) { | |
| items_[i].argN_ = non_ordered_items; | |
| ++non_ordered_items; | |
| } | |
| max_argN = non_ordered_items-1; | |
| } | |
| // C: set some member data : | |
| items_.resize(num_items, format_item_t(io::detail::const_or_not(fac).widen( ' ')) ); | |
| if(special_things) style_ |= special_needs; | |
| num_args_ = max_argN + 1; | |
| if(ordered_args) style_ |= ordered; | |
| else style_ &= ~ordered; | |
| return *this; | |
| } | |
| } // namespace boost | |
| #endif // BOOST_FORMAT_PARSING_HPP |