diff options
Diffstat (limited to 'boost/date_time/special_values_parser.hpp')
| -rw-r--r-- | boost/date_time/special_values_parser.hpp | 55 |
1 files changed, 32 insertions, 23 deletions
diff --git a/boost/date_time/special_values_parser.hpp b/boost/date_time/special_values_parser.hpp index e48ec5fda9..43748c74cd 100644 --- a/boost/date_time/special_values_parser.hpp +++ b/boost/date_time/special_values_parser.hpp @@ -34,14 +34,9 @@ namespace boost { namespace date_time { { public: typedef std::basic_string<charT> string_type; - //typedef std::basic_stringstream<charT> stringstream_type; + typedef std::basic_stringstream<charT> stringstream_type; typedef std::istreambuf_iterator<charT> stream_itr_type; - //typedef typename string_type::const_iterator const_itr; - //typedef typename date_type::year_type year_type; - //typedef typename date_type::month_type month_type; typedef typename date_type::duration_type duration_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; @@ -101,11 +96,37 @@ namespace boost { namespace date_time { m_sv_strings = parse_tree_type(phrases, static_cast<int>(not_a_date_time)); } - /* Does not return a special_value because if the parsing fails, - * the return value will always be not_a_date_time - * (mr.current_match retains its default value of -1 on a failed - * parse and that casts to not_a_date_time). */ - //! Sets match_results.current_match to the corresponding special_value or -1 + //! 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 @@ -114,18 +135,6 @@ namespace boost { namespace date_time { m_sv_strings.match(sitr, str_end, mr, level); return (mr.current_match != match_results::PARSE_ERROR); } - /*special_values 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); - if(mr.current_match == match_results::PARSE_ERROR) { - throw std::ios_base::failure("Parse failed. No match found for '" + mr.cache + "'"); - } - return static_cast<special_values>(mr.current_match); - }*/ - private: parse_tree_type m_sv_strings; |