[Scheme-reports] Date/time package John Cowan (10 May 2012 16:56 UTC)
Re: Date/time package Arthur A. Gleckler (10 May 2012 17:09 UTC)
Re: [Scheme-reports] Date/time package Peter Bex (10 May 2012 18:54 UTC)
Re: [Scheme-reports] Date/time package John Cowan (10 May 2012 21:07 UTC)
Re: [Scheme-reports] Date/time package Peter Bex (10 May 2012 21:58 UTC)
Re: [Scheme-reports] Date/time package Alan Watson (10 May 2012 22:07 UTC)
Re: [Scheme-reports] Date/time package Noah Lavine (10 May 2012 22:41 UTC)
Re: [Scheme-reports] Date/time package John Cowan (11 May 2012 02:43 UTC)
Re: [Scheme-reports] Date/time package John Cowan (11 May 2012 02:16 UTC)
Re: [Scheme-reports] Date/time package Peter Bex (11 May 2012 10:05 UTC)
Re: [Scheme-reports] Date/time package Peter Bex (11 May 2012 10:13 UTC)
Re: [Scheme-reports] Date/time package John Cowan (11 May 2012 14:35 UTC)
Re: [Scheme-reports] Date/time package John J Foerch (10 May 2012 23:40 UTC)
Re: [Scheme-reports] Date/time package John Cowan (11 May 2012 03:01 UTC)
Re: [Scheme-reports] Date/time package John J Foerch (11 May 2012 04:37 UTC)
Re: [Scheme-reports] Date/time package John Cowan (11 May 2012 04:44 UTC)
Re: [Scheme-reports] Date/time package John J Foerch (11 May 2012 05:25 UTC)
Re: [Scheme-reports] Date/time package Daniel Villeneuve (11 May 2012 03:35 UTC)

Re: [Scheme-reports] Date/time package Noah Lavine 10 May 2012 22:41 UTC

Hello,

> It just occurred to me that it might be useful if there was a
> "current-chronology" that behaves like "current-input-port", which
> is then parameterizable (maybe call-with-chronology).
>
> I'm not sure, it might also be overkill since you can't really do
> anything special to chronologies except query them.  Just wanted to
> put the idea out there to see what others think.

Here's a use case for that: I'm writing a program that wants to deal
with users in different time zones (maybe a web server or something
similar). My own program knows about which users are in which time
zone, and adjusts accordingly. But I'd also like to use a library for
pretty formatting, which unfortunately wasn't written with this case
in mind. I have no way to pass a chronology to this library. But if I
could use call-with-chronology, I wouldn't have to worry about that.

More generally, this lets people customize chronologies in functions
whose creators didn't think that users would want to change
chronologies. This seems like a common case, because most programs
only operate in one time zone at a time, but a few need to deal with
lots of time zones. So I would expect that lots of libraries wouldn't
let the user change the time zone, and a few users would have problems
because of this.

Noah Lavine

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