Re: [Chicken-users] Date/time problem (my code I am sure)

[elf]

the problem is in the module itself.  i have a fix for it.  the months are
borked (zero vs one indexing) and other such loveliness.

-elf

On Wed, 20 Dec 2006, Jeremy Cowgar wrote:

> I have written a few functions to help me in dealing with dates and times.
> vector->date was created because postgresql egg returns a vector for the
> date. The original (not stripped for including here) supports date, date and
> time depending on vector length. to-time was created so I can send a few
> different types to my functions, then finally, the source of the problem,
> distance-of-time-in-words is a copy of (don't get mad) ruby on rails function
> that displays things like "about a minute", "12 days", "13 hours", etc... for
> difference. It too has been severly stripped for including here.
>
> My problem is that when I use (currrent-date) the calculation from a date
> object using time-difference is **way** off. I am not sure if I am not
> creating a date object correctly via (make-date) or what. When I compare two
> vectors #(2006 12 10) to say #(2006 12 9) which is converted to a date type
> via make-date, that works fine, but comparing a #(2006 12 20) to
> (current-date) everything goes wacky.
>
> I have stripped the code to as little as possible to display the problem, can
> anyone offer any advice?
>
> ----
>
> (use srfi-19 srfi-19-io)
>
> (define (vector->date vec)
>   (make-date
>          0 0 0 0
>                   (vector-ref vec 2)
>                                  (vector-ref vec 1)
>                                           (vector-ref vec 0)
>                                                          0))
>
> (define (to-time obj)
>   (cond
>          ((time? obj)   obj)
>                   ((date? obj)   (date->time-utc obj))
>                                  ((vector? obj) (date->time-utc (vector->date 
> obj)))))
>
> (define (distance-of-time-in-words from #!optional (to (current-date)))
>   (let* ((from-time (to-time from))
>                (to-time (to-time to))
>                                                 (distance-in-seconds 
> (time-second (time-difference
>                                                                               
> from-time to-time))))
>           distance-in-seconds))
>
> (define vec1 (vector 2006 12 20))
> (define vec2 (vector 2006 12 19))
> (print (distance-of-time-in-words vec1))       ;; 675162109
> (print (distance-of-time-in-words vec1 vec2))  ;; 86400
> (exit)
>
> ----
>
> As you can see, the  675162109 number is wacky. That's 7,814 days. In order
> for this sample to work, you need to chicken-setup srfi-19 to get the
> date/time stuff.
>
> Oh, again, realize that these functiosn in my code do much more than
> presented here, i.e. the distance-of-time-in-words is useless basically in
> this example, but the real function continues much beyond the current
> example, just trimed for ease of finding the problem.
>
> Thanks for any help!
>
> Jeremy
>
>
>
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