/usr/include/boost/date_time
Edit: /usr/include/boost/date_time/special_values_parser.hpp (6161B)
#ifndef DATE_TIME_SPECIAL_VALUES_PARSER_HPP__
#define DATE_TIME_SPECIAL_VALUES_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:
*/
#include "boost/date_time/string_parse_tree.hpp"
#include "boost/date_time/special_defs.hpp"
#include
#include
namespace boost { namespace date_time {
//! Class for special_value parsing
/*!
* TODO: add doc-comments for which elements can be changed
* Parses input stream for strings representing special_values.
* Special values parsed are:
* - not_a_date_time
* - neg_infin
* - pod_infin
* - min_date_time
* - max_date_time
*/
template
class special_values_parser
{
public:
typedef std::basic_string string_type;
typedef std::basic_stringstream stringstream_type;
typedef std::istreambuf_iterator stream_itr_type;
typedef typename date_type::duration_type duration_type;
typedef string_parse_tree parse_tree_type;
typedef typename parse_tree_type::parse_match_result_type match_results;
typedef std::vector > collection_type;
typedef charT char_type;
static const char_type nadt_string[16];
static const char_type neg_inf_string[10];
static const char_type pos_inf_string[10];
static const char_type min_date_time_string[18];
static const char_type max_date_time_string[18];
//! Creates a special_values_parser with the default set of "sv_strings"
special_values_parser()
{
sv_strings(string_type(nadt_string),
string_type(neg_inf_string),
string_type(pos_inf_string),
string_type(min_date_time_string),
string_type(max_date_time_string));
}
//! Creates a special_values_parser using a user defined set of element strings
special_values_parser(const string_type& nadt_str,
const string_type& neg_inf_str,
const string_type& pos_inf_str,
const string_type& min_dt_str,
const string_type& max_dt_str)
{
sv_strings(nadt_str, neg_inf_str, pos_inf_str, min_dt_str, max_dt_str);
}
special_values_parser(typename collection_type::iterator beg, typename collection_type::iterator end)
{
collection_type phrases;
std::copy(beg, end, std::back_inserter(phrases));
m_sv_strings = parse_tree_type(phrases, static_cast(not_a_date_time));
}
//! Replace special value strings
void sv_strings(const string_type& nadt_str,
const string_type& neg_inf_str,
const string_type& pos_inf_str,
const string_type& min_dt_str,
const string_type& max_dt_str)
{
collection_type phrases;
phrases.push_back(nadt_str);
phrases.push_back(neg_inf_str);
phrases.push_back(pos_inf_str);
phrases.push_back(min_dt_str);
phrases.push_back(max_dt_str);
m_sv_strings = parse_tree_type(phrases, static_cast(not_a_date_time));
}
//! The parser is expensive to create, and not thread-safe so it cannot be static
//! therefore given a string, determine if it is likely to be a special value.
//! A negative response is a definite no, whereas a positive is only likely and
//! match() should be called and return value checked.
//! \param[in] str the string to check
//! \returns false if it is definitely not a special value
static bool likely(const string_type& str)
{
if (!str.empty()) {
switch (str[0]) {
// See string definitions at the end of this class..
case '+':
case '-':
case 'n':
case 'm':
return true;
default:
break;
}
}
return false;
}
//! Given an input iterator, attempt to match it to a known special value
//! \param[in] sitr the start iterator
//! \param[in] str_end the end iterator
//! \param[out] mr the match result:
//! mr.current_match is set to the corresponding special_value or -1
//! \returns whether something matched
bool match(stream_itr_type& sitr,
stream_itr_type& str_end,
match_results& mr) const
{
unsigned int level = 0;
m_sv_strings.match(sitr, str_end, mr, level);
return (mr.current_match != match_results::PARSE_ERROR);
}
private:
parse_tree_type m_sv_strings;
};
template
const typename special_values_parser::char_type
special_values_parser::nadt_string[16] =
{'n','o','t','-','a','-','d','a','t','e','-','t','i','m','e'};
template
const typename special_values_parser::char_type
special_values_parser::neg_inf_string[10] =
{'-','i','n','f','i','n','i','t','y'};
template
const typename special_values_parser::char_type
special_values_parser::pos_inf_string[10] =
{'+','i','n','f','i','n','i','t','y'};
template
const typename special_values_parser::char_type
special_values_parser::min_date_time_string[18] =
{'m','i','n','i','m','u','m','-','d','a','t','e','-','t','i','m','e'};
template
const typename special_values_parser::char_type
special_values_parser::max_date_time_string[18] =
{'m','a','x','i','m','u','m','-','d','a','t','e','-','t','i','m','e'};
} } //namespace
#endif // DATE_TIME_SPECIAL_VALUES_PARSER_HPP__