pub fn parse_duration(s: &str) -> Option<DurationParts>Expand description
Parses an ISO-8601 duration string (P[nY][nM][nW][nD][T[nH][nM][nS]],
each n an optional-sign decimal) into raw DurationFields, then
normalizes the same way duration({...}) does – construction from
text and from a map are the same operation once the units are pulled
apart, see normalize_duration’s docs.
Deliberately does not handle the alternative “combined date-time”
duration representation (P2012-02-02T14:37:21.545, ISO-8601’s other
duration syntax) – a real gap (see the README), not a silent
misparse: that string doesn’t match P followed by number+letter
pairs, so this returns None, the same “reject, don’t guess” outcome
parse_date gives an unsupported date string form.