Howdy folks
Looking at those weird time! values must have boggled my brain. Please read
"hour" for "year" in my previous post #121264. The message is copied below
with correction. (Bo: can you substitute for previous post to feedback?)
Sorry for the confusion
Larry
----- Original Message -----
From: Larry Palmiter <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Thursday, March 09, 2000 11:35 AM
Subject: [REBOL] Weird stuff with time Re:
> Hi Allen
>
> Interesting. I think the largest time value for hour which works in the
> expected way is:
>
> >> 596522:10:12 ;this is ok (and far beyond any reasonable hour
> value)
> == 596522:10:12
>
> >> 596523:10:12
> ** Syntax Error: Invalid time -- 596523:10:12.
> ** Where: (line 1) 596523:10:12
>
> REBOL allows integers to be entered for the hour which are larger than
> allowed by the REBOL integer! datatype. This is probably not what was
> intended. Also there are further anomalies.
>
> >> to-time probe rejoin [2 ** 32 ":10:12"] ;multiples of 2 ** 32
> produce 0 for the hour
> "4294967296:10:12"
> == 0:10:12
>
> >> to-time probe rejoin [2 ** 32 + 1 ":10:12"] ;we can add 1 and the
hour
> increments
> "4294967297:10:12"
> == 1:10:12
>
> >> to-time probe rejoin [2 ** 32 - 1 ":10:12"] ;but if we subtract, big
> surprise!
> "4294967295:10:12"
> == -0:49:48
>
> The largest value for hour which does not lead to an error for the 'rejoin
> block is:
>
> >> to-time probe rejoin [999999999999999 ":10:12"]
> "999999999999999:10:12"
> == 183645:36:20
>
> This limitation is due to the way 'form works, if we enter a larger value
> directly, we get
>
> >> 1000000000000000:10:12
> == 183646:36:20
>
> The weird numbers are due to some sort of wrapping of the integer values.
> The behavior is complex, so the explanation you requested will likely have
> to come from someone at Rebol Tech with access to the underlying C-code.
>
> One simple fix would be to return the "Invalid time" error for values of
> hour greater than 596522.
>
> I am copying this to feedback as a bug. You, of course, deserve full
credit
> for the discovery. Good catch!
>
> Cheers
>
> Larry
>
> ----- Original Message -----
> From: <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, March 09, 2000 4:44 AM
> Subject: [REBOL] Weird stuff with time
>
>
> > Whilst testing to find the upper limits of time/hour (for an up-time
> > monitoring script)
> > I came across these anomalies in time!
> >
> > Can anyone explain what is happening here?
> > How come some large numbers for hours give an error and others
> > return bizare numbers?
> >
> > x: 2000:10:12
> > == 2000:10:12
> > >> x: 200000:10:12
> > == 200000:10:12
> > >> x: 2000000:10:12
> > ** Syntax Error: Invalid time -- 2000000:10:12.
> > ** Where: (line 1) x: 2000000:10:12
> > >> x: 2000000:10:12
> > ** Syntax Error: Invalid time -- 2000000:10:12.
> > ** Where: (line 1) x: 2000000:10:12
> > >> x: 20000000:10:12
> > ** Syntax Error: Invalid time -- 20000000:10:12.
> > ** Where: (line 1) x: 20000000:10:12
> > >> x: 200000000:10:12
> > ** Syntax Error: Invalid time -- 200000000:10:12.
> > ** Where: (line 1) x: 200000000:10:12
> > >> x: 2000000000:10:12
> > ** Syntax Error: Invalid time -- 2000000000:10:12.
> > ** Where: (line 1) x: 2000000000:10:12
> > >> x: 20000000000:10:12
> > == -231041:32:12
> > >> x: 200000000000:10:12
> > == 75676:02:44
> > >> x: 2000000000000:10:12
> > == -436287:32:44
> > >> x: 20000000000000:10:12
> > == 409308:53:56
> >
> > Cheers,
> >
> > Allen K
> >
>
