boost/date_time/date_generator_parser.hpp
#ifndef DATE_TIME_DATE_GENERATOR_PARSER_HPP__
#define DATE_TIME_DATE_GENERATOR_PARSER_HPP__
/* Copyright (c) 2005 CrystalClear Software, Inc.
* Use, modification and distribution is subject to the
* Boost Software License, Version 1.0. (See accompanying
* file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
* Author: Jeff Garland, Bart Garst
* $Date: 2008-11-12 14:37:53 -0500 (Wed, 12 Nov 2008) $
*/
#include <string>
#include <vector>
#include <iterator> // istreambuf_iterator
#include <boost/throw_exception.hpp>
#include <boost/date_time/compiler_config.hpp>
#include <boost/date_time/string_parse_tree.hpp>
#include <boost/date_time/date_generators.hpp>
#include <boost/date_time/format_date_parser.hpp>
namespace boost { namespace date_time {
//! Class for date_generator parsing
/*! The elements of a date_generator "phrase" are parsed from the input stream in a
* particular order. All elements are required and the order in which they appear
* cannot change, however, the elements themselves can be changed. The default
* elements and their order are as follows:
*
* - partial_date => "dd Month"
* - nth_day_of_the_week_in_month => "nth weekday of month"
* - first_day_of_the_week_in_month => "first weekday of month"
* - last_day_of_the_week_in_month => "last weekday of month"
* - first_day_of_the_week_after => "weekday after"
* - first_day_of_the_week_before => "weekday before"
*
* Weekday and Month names and formats are handled via the date_input_facet.
*
*/
template<class date_type, typename charT>
class date_generator_parser
{
public:
typedef std::basic_string<charT> string_type;
typedef std::istreambuf_iterator<charT> stream_itr_type;
typedef typename date_type::month_type month_type;
typedef typename date_type::day_of_week_type day_of_week_type;
typedef typename date_type::day_type day_type;
typedef string_parse_tree<charT> parse_tree_type;
typedef typename parse_tree_type::parse_match_result_type match_results;
typedef std::vector<std::basic_string<charT> > collection_type;
typedef partial_date<date_type> partial_date_type;
typedef nth_kday_of_month<date_type> nth_kday_type;
typedef first_kday_of_month<date_type> first_kday_type;
typedef last_kday_of_month<date_type> last_kday_type;
typedef first_kday_after<date_type> kday_after_type;
typedef first_kday_before<date_type> kday_before_type;
typedef charT char_type;
static const char_type first_string[6];
static const char_type second_string[7];
static const char_type third_string[6];
static const char_type fourth_string[7];
static const char_type fifth_string[6];
static const char_type last_string[5];
static const char_type before_string[8];
static const char_type after_string[6];
static const char_type of_string[3];
enum phrase_elements {first=0, second, third, fourth, fifth, last,
before, after, of, number_of_phrase_elements};
//! Creates a date_generator_parser with the default set of "element_strings"
date_generator_parser()
{
element_strings(string_type(first_string),
string_type(second_string),
string_type(third_string),
string_type(fourth_string),
string_type(fifth_string),
string_type(last_string),
string_type(before_string),
string_type(after_string),
string_type(of_string));
}
//! Creates a date_generator_parser using a user defined set of element strings
date_generator_parser(const string_type& first_str,
const string_type& second_str,
const string_type& third_str,
const string_type& fourth_str,
const string_type& fifth_str,
const string_type& last_str,
const string_type& before_str,
const string_type& after_str,
const string_type& of_str)
{
element_strings(first_str, second_str, third_str, fourth_str, fifth_str,
last_str, before_str, after_str, of_str);
}
//! Replace strings that determine nth week for generator
void element_strings(const string_type& first_str,
const string_type& second_str,
const string_type& third_str,
const string_type& fourth_str,
const string_type& fifth_str,
const string_type& last_str,
const string_type& before_str,
const string_type& after_str,
const string_type& of_str)
{
collection_type phrases;
phrases.push_back(first_str);
phrases.push_back(second_str);
phrases.push_back(third_str);
phrases.push_back(fourth_str);
phrases.push_back(fifth_str);
phrases.push_back(last_str);
phrases.push_back(before_str);
phrases.push_back(after_str);
phrases.push_back(of_str);
m_element_strings = parse_tree_type(phrases, this->first); // enum first
}
void element_strings(const collection_type& col)
{
m_element_strings = parse_tree_type(col, this->first); // enum first
}
//! returns partial_date parsed from stream
template<class facet_type>
partial_date_type
get_partial_date_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
day_type d(1);
month_type m(1);
facet.get(sitr, stream_end, a_ios, d);
facet.get(sitr, stream_end, a_ios, m);
return partial_date_type(d,m);
}
//! returns nth_kday_of_week parsed from stream
template<class facet_type>
nth_kday_type
get_nth_kday_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
typename nth_kday_type::week_num wn;
day_of_week_type wd(0); // no default constructor
month_type m(1); // no default constructor
match_results mr = m_element_strings.match(sitr, stream_end);
switch(mr.current_match) {
case first : { wn = nth_kday_type::first; break; }
case second : { wn = nth_kday_type::second; break; }
case third : { wn = nth_kday_type::third; break; }
case fourth : { wn = nth_kday_type::fourth; break; }
case fifth : { wn = nth_kday_type::fifth; break; }
default:
{
boost::throw_exception(std::ios_base::failure("Parse failed. No match found for '" + mr.cache + "'"));
BOOST_DATE_TIME_UNREACHABLE_EXPRESSION(wn = nth_kday_type::first);
}
} // week num
facet.get(sitr, stream_end, a_ios, wd); // day_of_week
extract_element(sitr, stream_end, of); // "of" element
facet.get(sitr, stream_end, a_ios, m); // month
return nth_kday_type(wn, wd, m);
}
//! returns first_kday_of_week parsed from stream
template<class facet_type>
first_kday_type
get_first_kday_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
day_of_week_type wd(0); // no default constructor
month_type m(1); // no default constructor
extract_element(sitr, stream_end, first); // "first" element
facet.get(sitr, stream_end, a_ios, wd); // day_of_week
extract_element(sitr, stream_end, of); // "of" element
facet.get(sitr, stream_end, a_ios, m); // month
return first_kday_type(wd, m);
}
//! returns last_kday_of_week parsed from stream
template<class facet_type>
last_kday_type
get_last_kday_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
day_of_week_type wd(0); // no default constructor
month_type m(1); // no default constructor
extract_element(sitr, stream_end, last); // "last" element
facet.get(sitr, stream_end, a_ios, wd); // day_of_week
extract_element(sitr, stream_end, of); // "of" element
facet.get(sitr, stream_end, a_ios, m); // month
return last_kday_type(wd, m);
}
//! returns first_kday_of_week parsed from stream
template<class facet_type>
kday_before_type
get_kday_before_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
day_of_week_type wd(0); // no default constructor
facet.get(sitr, stream_end, a_ios, wd); // day_of_week
extract_element(sitr, stream_end, before);// "before" element
return kday_before_type(wd);
}
//! returns first_kday_of_week parsed from stream
template<class facet_type>
kday_after_type
get_kday_after_type(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
day_of_week_type wd(0); // no default constructor
facet.get(sitr, stream_end, a_ios, wd); // day_of_week
extract_element(sitr, stream_end, after); // "after" element
return kday_after_type(wd);
}
private:
parse_tree_type m_element_strings;
//! Extracts phrase element from input. Throws ios_base::failure on error.
void extract_element(stream_itr_type& sitr,
stream_itr_type& stream_end,
typename date_generator_parser::phrase_elements ele) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
match_results mr = m_element_strings.match(sitr, stream_end);
if(mr.current_match != ele) {
boost::throw_exception(std::ios_base::failure("Parse failed. No match found for '" + mr.cache + "'"));
}
}
};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::first_string[6] =
{'f','i','r','s','t'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::second_string[7] =
{'s','e','c','o','n','d'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::third_string[6] =
{'t','h','i','r','d'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::fourth_string[7] =
{'f','o','u','r','t','h'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::fifth_string[6] =
{'f','i','f','t','h'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::last_string[5] =
{'l','a','s','t'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::before_string[8] =
{'b','e','f','o','r','e'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::after_string[6] =
{'a','f','t','e','r'};
template<class date_type, class CharT>
const typename date_generator_parser<date_type, CharT>::char_type
date_generator_parser<date_type, CharT>::of_string[3] =
{'o','f'};
} } //namespace
#endif // DATE_TIME_DATE_GENERATOR_PARSER_HPP__