Peter Bex scripsit: > I think a comfortable, complete date/time-manipulation is one thing that > Scheme is sorely lacking. We have SRFI-19, but it is a bit unwieldy and > not very complete.
I have written up a proposal for WG2 which can be found at http://trac.sacrideo.us/wg/wiki/TimeAdvancedCowan , with a supplement on durations and intervals at http://trac.sacrideo.us/wg/wiki/TimePeriodsCowan . It's based loosely on the Java package JodaTime, but adapted to the nature of a dynamically typed language. It is certainly comprehensive; how comfortable it is, is for others to judge. If anyone's interested, please take a look and comment here. > (How, for example, do you convert a given time in a > zone to another zone? How do you go back a month? etc) (define iso (chronology 'iso)) (define new-york-zone (chronology-with-time-zone 'America/New_York iso "America/New_York")) (define dutch-zone (chronology-with-time-zone 'Europe/Amsterdam iso "Europe/Amsterdam")) (define new-york-moment (make-date new-york-zone '((year . 2012) (month-of-year . 5) (day-of-month . 10) (hour-of-day . 12) (minute-of-hour . 19) (second-of-minute . 30)))) (define dutch-moment (convert-date dutch-zone new-york-moment)) (date-field dutch-moment 'hour-of-day) => 18 (define last-january new-york '((year . 2012) (month-of-year . 1))) (define last-december (date-increment last-january 'month-of-year -1)) (date-field last-december 'month-of-year) => 12 (date-field last-january 'year) => 2011 -- Schlingt dreifach einen Kreis vom dies! John Cowan <co...@ccil.org> Schliesst euer Aug vor heiliger Schau, http://www.ccil.org/~cowan Denn er genoss vom Honig-Tau, Und trank die Milch vom Paradies. --Coleridge (tr. Politzer) _______________________________________________ Scheme-reports mailing list Scheme-reports@scheme-reports.org http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
