[ENH] local vs. UTC time
Lex Spoon
lex at cc.gatech.edu
Fri Jun 30 00:34:32 UTC 2000
Oh yeah, we may as well go with ANSI. The plugin is extremely easy to
use--it returns a 10-element array, with 5 elements each for UTC and
local date/time. Should one of us merge this stuff with your ANSI code?
I'm not sure I have the right tools to mess with these changesets you
have, but I'll update them if you point me in the right direction.
Note that we really do need a new time primitive; currently you can only
get local time or UTC, and not both. Everybody's trick is to just stick
the UTC offset in a global variable, but this approach doesn't work when
either:
1. daylight savings kicks in.
2. an image gets shipped to somewhere in a different time zone.
-Lex
"R. A. Harmon" <harmonra at webname.com> wrote:
> At 05:05 PM 6/28/00 -700, "lex spoon" <lex at cc.gatech.edu> wrote:
> >Here are a pair of changesets that let Squeak discern local vs. UTC
> >time. It adds one primitive, which returns both the local time and UTC
> >in parallel. Squeak-level code can then interpret this information as
> >needed.
> >
> >The first changeset defines the primitive and a plugin that implements
> >it. It should be fairly portable, but I've only tried it on Linux. The
> >second changeset updates the Time class to use the new plugin when its
> >present, and it updates Celeste to make date stamps with it.
> >
> >How does this look to people? It seems to allow the following basic
> >time functions, with a minimum of fuss:
> >
> > 1. Return a UTC time precise to the second. This is useful when
> >Squeak's are talking to each other from different places in the world.
> >It's also precisely what's needed for building a proper HTTP cache.
> >
> > 2. Return a local time precise to the second. This is useful for clock
> >and calender displays.
> >
> > 3. Return a local time plus a delta from UTC. This is what email is
> >happiest with.
> >
> >
> >
> >Is anything critical missing? What else would people like to be able to
> >do with time? If this looks good, let's put it in the main system.
>
> I think the ANSI Date And Time protocol messages should do the above. I've
> implemented in Squeak it along with all the ANSI messages except for Stream
> and FileStream protocols and maybe a couple Collection protocol messages.
>
> I've reworked the Camp Smalltalk ANSI tests for Squeak released by Ralph E.
> Johnson for my ANSI implementation. The reworked version,
> ANSIChgSeta02r01Sqkv02r07.ZIP, containing Squeak ANSI messages, tests, and
> support is now available at my web page:
>
> http://homepage2.rconnect.com/raharmon/
>
>
> I think Squeak Central is looking at incorporating the ANSI messages in the
> standard release. I think it might be a more portable and easier route to
> use the ANSI messages for doing the time stuff above.
>
>
>
>
> --
> Richard A. Harmon "The only good zombie is a dead zombie"
> harmonra at webname.com E. G. McCarthy
> Spencer, Iowa
More information about the Squeak-dev
mailing list
|