Bug #84777 for DateTime: partial DateTime::Duration ordering without a base datetime

> Sun Apr 21 07:41:39 2013: Request 84777 was acted upon. > Transaction: Ticket created by TOBYINK > Queue: DateTime > Subject: partial DateTime::Duration ordering without a base datetime > Broken in: (no value) > Severity: Wishlist > Owner: Nobody > Requestors: mail@tobyinkster.co.uk > Status: new > Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=84777 > > > > It would be nice to have a DateTime::Duration method that could "compare" without a base DateTime along the lines of the comparison specified for xs:duration... > > http://www.w3.org/TR/xmlschema-2/#duration > > This is a partial ordering, so that: > > 364 days < 1 year > 365 days ?? 1 year > 366 days ?? 1 year > 367 days > 1 year > > I need an implementation of this, so am planning on writing it some time next week. Should I write it as a separate module, or do you want me to write it as a contribution to DateTime::Duration itself?

> Queue: DateTime > Ticket <URL: https://rt.cpan.org/Ticket/Display.html?id=84777 > > > OK. Well, FYI, turns out to be surprisingly easy: > > sub duration_compare > { > { "-1-1-1-1" => -1, "0000" => 0, "1111" => 1 }->{ > join q[], > map "DateTime::Duration"->compare(@_[0,1], $_), > map +( > /^(\d{4})-(\d{2})-(\d{2})$/ && "DateTime"->new( > year => $1, > month => $2, > day => $3, > hour => 0, > minute => 0, > second => 0, > nanosecond => 0, > time_zone => "UTC", > ) > ), > qw( 1696-09-01 1697-02-01 1903-03-01 1903-07-01 ) > } > } > > This will tell you that 2 years is longer than 729 days; but 2 years versus 730 or 731 days is indeterminable; while 2 years is shorter than 732 days.