boost/date_time/time_parsing.hpp
#ifndef _DATE_TIME_TIME_PARSING_HPP___ #define _DATE_TIME_TIME_PARSING_HPP___ /* Copyright (c) 2002,2003 CrystalClear Software, Inc. * Use, modification and distribution is subject to the * Boost Software License, Version 1.0. (See accompanying * file LICENSE-1.0 or http://www.boost.org/LICENSE-1.0) * Author: Jeff Garland, Bart Garst * $Date: 2004/10/03 14:58:43 $ */ #include "boost/tokenizer.hpp" #include "boost/lexical_cast.hpp" #include "boost/date_time/date_parsing.hpp" #include "boost/cstdint.hpp" #include <iostream> namespace boost { namespace date_time { //! computes exponential math like 2^8 => 256, only works with positive integers //Not general purpose, but needed b/c std::pow is not available //everywehere. Hasn't been tested with negatives and zeros template<class int_type> inline int_type power(int_type base, int_type exponent) { int_type result = 1; for(int i = 0; i < exponent; ++i){ result *= base; } return result; } //! Creates a time_duration object from a delimited string /*! Expected format for string is "[-]h[h][:mm][:ss][.fff]". * A negative duration will be created if the first character in * string is a '-', all other '-' will be treated as delimiters. * Accepted delimiters are "-:,.". */ template<class time_duration> inline time_duration parse_delimited_time_duration(const std::string& s) { unsigned short min=0, sec =0; int hour =0; bool is_neg = (s.at(0) == '-'); boost::int64_t fs=0; int pos = 0; char_separator<char> sep("-:,."); tokenizer<char_separator<char> > tok(s,sep); for(tokenizer<char_separator<char> >::iterator beg=tok.begin(); beg!=tok.end();++beg){ switch(pos) { case 0: { hour = boost::lexical_cast<int>(*beg); break; } case 1: { min = boost::lexical_cast<unsigned short>(*beg); break; } case 2: { sec = boost::lexical_cast<unsigned short>(*beg); break; }; case 3: { //Works around a bug in MSVC 6 library that does not support //operator>> thus meaning lexical_cast will fail to compile. #if (defined(BOOST_MSVC) && (_MSC_VER <= 1200)) // 1200 == VC++ 6.0 fs = _atoi64(beg->c_str()); // msvc wouldn't compile 'time_duration::num_fractional_digits()' // (required template argument list) as a workaround a temp // time_duration object was used time_duration td(hour,min,sec,fs); int precision = td.num_fractional_digits(); #else fs = boost::lexical_cast<boost::int64_t>(*beg); int precision = time_duration::num_fractional_digits(); #endif int digits = beg->length(); if(digits < precision){ // leading zeros get dropped from the string, // "1:01:01.1" would yield .000001 instead of .100000 // the power() compensates for the missing decimal places fs *= power(10, precision - digits); } break; } }//switch pos++; } if(is_neg) { return -time_duration(hour, min, sec, fs); } else { return time_duration(hour, min, sec, fs); } } //! Utility function to split appart string inline bool split(const std::string& s, char sep, std::string& first, std::string& second) { int sep_pos = static_cast<int>(s.find(sep)); first = s.substr(0,sep_pos); second = s.substr(sep_pos+1); return true; } template<class time_type> inline time_type parse_delimited_time(const std::string& s, char sep) { typedef typename time_type::time_duration_type time_duration; typedef typename time_type::date_type date_type; //split date/time on a unique delimiter char such as ' ' or 'T' std::string date_string, tod_string; split(s, sep, date_string, tod_string); //call parse_date with first string date_type d = parse_date<date_type>(date_string); //call parse_time_duration with remaining string time_duration td = parse_delimited_time_duration<time_duration>(tod_string); //construct a time return time_type(d, td); } //! Parse time duration part of an iso time of form: [-]hhmmss (eg: 120259 is 12 hours 2 min 59 seconds) template<class time_duration> inline time_duration parse_undelimited_time_duration(const std::string& s) { int offsets[] = {2,2,2}; int pos = 0, sign = 0; int hours = 0; short min=0, sec=0; // increment one position if the string was "signed" if(s.at(sign) == '-') { ++sign; } // stlport choked when passing s.substr() to tokenizer // using a new string fixed the error std::string remain = s.substr(sign); boost::offset_separator osf(offsets, offsets+3); boost::tokenizer<boost::offset_separator> tok(remain, osf); for(boost::tokenizer<boost::offset_separator>::iterator ti=tok.begin(); ti!=tok.end();++ti){ switch(pos) { case 0: { hours = boost::lexical_cast<int>(*ti); break; } case 1: { min = boost::lexical_cast<short>(*ti); break; } case 2: { sec = boost::lexical_cast<short>(*ti); break; } }; pos++; } if(sign) { return -time_duration(hours, min, sec); } else { return time_duration(hours, min, sec); } } //! Parse time string of form YYYYMMDDThhmmss where T is delimeter between date and time template<class time_type> inline time_type parse_iso_time(const std::string& s, char sep) { typedef typename time_type::time_duration_type time_duration; typedef typename time_type::date_type date_type; //split date/time on a unique delimiter char such as ' ' or 'T' std::string date_string, tod_string; split(s, sep, date_string, tod_string); //call parse_date with first string date_type d = parse_undelimited_date<date_type>(date_string); //call parse_time_duration with remaining string time_duration td = parse_undelimited_time_duration<time_duration>(tod_string); //construct a time return time_type(d, td); } } }//namespace date_time #endif