Hi! Is it possible access captured group from another scope in the semantic action? Can I write a lazy function somehow and access another scope? The following code results in ”bad_lexical_cast” exception, likely due to the named capture "Year" is an empty string in the "outer scope". const sregex yyyymmdd = (Year=_d>>_d>>_d>>_d) >> (Month= _d>>_d)
(Day= _d>>_d);
sregex rx = yyyymmdd [ tm_year(t) = as<int>(Year) - 1900 /*, …
*/ ] // bad lexical cast: source type value could not be interpreted
as target
>> hhmmss [ tm_hour(t) = as<int>(Hour) /*, …*/ ]
;
In my case the regex has no recursion, no captured repeated groups, so
I can't understand really why I got nested result set.
Dumping the nested result tree indicates that the values are captured
in another ”scope”. But this is in the match_result<> set, and I can't
figure out if there is any equivalent set available inside the
semantic action.
20140119190000 #rx
day =
hour =
minute =
month =
second =
year =
20140119 #yyyymmdd
day = 19
hour =
minute =
month = 01
second =
year = 2014
190000 #hhmmss
day =
hour = 19
minute = 00
month =
second = 00
year =
I’m asking mostly for educational reason.
Thanks for any hints!
perrog
Code:
mark_tag Year(1),Month(2),Day(3),Hour(4),Minute(5),Second(6), Micro(7);
const sregex yyyymmdd = (Year=_d>>_d>>_d>>_d) >> (Month= _d>>_d) >>
(Day= _d>>_d);
const sregex hhmmss = (Hour=_d>>_d)>>(Minute=_d>>_d)>>(Second=_d>>_d);
bool is_datetime(std::string const& input)
{
// …don’t need any semantic actions when validating…
smatch ignore;
sregex rx = yyyymmdd >> hhmmss;
return regex_match(input, ignore, rx);
}
bool get_datetime(std::string const& input, struct tm *time)
{
local