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#ifndef DATETIME_PERIOD_PARSER_HPP___
#define DATETIME_PERIOD_PARSER_HPP___
/* Copyright (c) 2002-2004 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: 2008-11-13 15:10:23 -0500 (Thu, 13 Nov 2008) $
*/
#include <boost/throw_exception.hpp>
#include <boost/date_time/string_parse_tree.hpp>
#include <boost/date_time/string_convert.hpp>
namespace boost { namespace date_time {
//! Not a facet, but a class used to specify and control period parsing
/*! Provides settings for the following:
* - period_separator -- default '/'
* - period_open_start_delimeter -- default '['
* - period_open_range_end_delimeter -- default ')'
* - period_closed_range_end_delimeter -- default ']'
* - display_as_open_range, display_as_closed_range -- default closed_range
*
* For a typical date_period, the contents of the input stream would be
*@code
* [2004-Jan-04/2004-Feb-01]
*@endcode
* where the date format is controlled by the date facet
*/
template<class date_type, typename CharT>
class period_parser {
public:
typedef std::basic_string<CharT> string_type;
typedef CharT char_type;
//typedef typename std::basic_string<char_type>::const_iterator const_itr_type;
typedef std::istreambuf_iterator<CharT> stream_itr_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;
static const char_type default_period_separator[2];
static const char_type default_period_start_delimeter[2];
static const char_type default_period_open_range_end_delimeter[2];
static const char_type default_period_closed_range_end_delimeter[2];
enum period_range_option { AS_OPEN_RANGE, AS_CLOSED_RANGE };
//! Constructor that sets up period parser options
period_parser(period_range_option range_opt = AS_CLOSED_RANGE,
const char_type* const period_separator = default_period_separator,
const char_type* const period_start_delimeter = default_period_start_delimeter,
const char_type* const period_open_range_end_delimeter = default_period_open_range_end_delimeter,
const char_type* const period_closed_range_end_delimeter = default_period_closed_range_end_delimeter)
: m_range_option(range_opt)
{
delimiters.push_back(string_type(period_separator));
delimiters.push_back(string_type(period_start_delimeter));
delimiters.push_back(string_type(period_open_range_end_delimeter));
delimiters.push_back(string_type(period_closed_range_end_delimeter));
}
period_parser(const period_parser<date_type,CharT>& p_parser)
{
this->delimiters = p_parser.delimiters;
this->m_range_option = p_parser.m_range_option;
}
period_range_option range_option() const
{
return m_range_option;
}
void range_option(period_range_option option)
{
m_range_option = option;
}
collection_type delimiter_strings() const
{
return delimiters;
}
void delimiter_strings(const string_type& separator,
const string_type& start_delim,
const string_type& open_end_delim,
const string_type& closed_end_delim)
{
delimiters.clear();
delimiters.push_back(separator);
delimiters.push_back(start_delim);
delimiters.push_back(open_end_delim);
delimiters.push_back(closed_end_delim);
}
//! Generic code to parse a period -- no matter the period type.
/*! This generic code will parse any period using a facet to
* to get the 'elements'. For example, in the case of a date_period
* the elements will be instances of a date which will be parsed
* according the to setup in the passed facet parameter.
*
* The steps for parsing a period are always the same:
* - consume the start delimiter
* - get start element
* - consume the separator
* - get either last or end element depending on range settings
* - consume the end delimeter depending on range settings
*
* Thus for a typical date period the contents of the input stream
* might look like this:
*@code
*
* [March 01, 2004/June 07, 2004] <-- closed range
* [March 01, 2004/June 08, 2004) <-- open range
*
*@endcode
*/
template<class period_type, class duration_type, class facet_type>
period_type get_period(stream_itr_type& sitr,
stream_itr_type& stream_end,
std::ios_base& a_ios,
const period_type& /* p */,
const duration_type& dur_unit,
const facet_type& facet) const
{
// skip leading whitespace
while(std::isspace(*sitr) && sitr != stream_end) { ++sitr; }
typedef typename period_type::point_type point_type;
point_type p1(not_a_date_time), p2(not_a_date_time);
consume_delim(sitr, stream_end, delimiters[START]); // start delim
facet.get(sitr, stream_end, a_ios, p1); // first point
consume_delim(sitr, stream_end, delimiters[SEPARATOR]); // separator
facet.get(sitr, stream_end, a_ios, p2); // second point
// period construction parameters are always open range [begin, end)
if (m_range_option == AS_CLOSED_RANGE) {
consume_delim(sitr, stream_end, delimiters[CLOSED_END]);// end delim
// add 1 duration unit to p2 to make range open
p2 += dur_unit;
}
else {
consume_delim(sitr, stream_end, delimiters[OPEN_END]); // end delim
}
return period_type(p1, p2);
}
private:
collection_type delimiters;
period_range_option m_range_option;
enum delim_ids { SEPARATOR, START, OPEN_END, CLOSED_END };
//! throws ios_base::failure if delimiter and parsed data do not match
void consume_delim(stream_itr_type& sitr,
stream_itr_type& stream_end,
const string_type& delim) const
{
/* string_parse_tree will not parse a string of punctuation characters
* without knowing exactly how many characters to process
* Ex [2000. Will not parse out the '[' string without knowing
* to process only one character. By using length of the delimiter
* string we can safely iterate past it. */
string_type s;
for(unsigned int i = 0; i < delim.length() && sitr != stream_end; ++i) {
s += *sitr;
++sitr;
}
if(s != delim) {
boost::throw_exception(std::ios_base::failure("Parse failed. Expected '"
+ convert_string_type<char_type,char>(delim) + "' but found '" + convert_string_type<char_type,char>(s) + "'"));
}
}
};
template <class date_type, class char_type>
const typename period_parser<date_type, char_type>::char_type
period_parser<date_type, char_type>::default_period_separator[2] = {'/'};
template <class date_type, class char_type>
const typename period_parser<date_type, char_type>::char_type
period_parser<date_type, char_type>::default_period_start_delimeter[2] = {'['};
template <class date_type, class char_type>
const typename period_parser<date_type, char_type>::char_type
period_parser<date_type, char_type>::default_period_open_range_end_delimeter[2] = {')'};
template <class date_type, class char_type>
const typename period_parser<date_type, char_type>::char_type
period_parser<date_type, char_type>::default_period_closed_range_end_delimeter[2] = {']'};
} } //namespace boost::date_time
#endif // DATETIME_PERIOD_PARSER_HPP___
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