Proposed changes to SRFI-19
shivers@xxxxxx
(24 Apr 2000 03:06 UTC)
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Re: Proposed changes to SRFI-19 Marc Feeley (24 Apr 2000 14:45 UTC)
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Time
shivers@xxxxxx
(24 Apr 2000 15:33 UTC)
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Re: Time
Marc Feeley
(24 Apr 2000 16:26 UTC)
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RE: Time
Will Fitzgerald
(24 Apr 2000 16:41 UTC)
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Note #1: The basic representation of time
Will Fitzgerald
(13 Jun 2000 20:07 UTC)
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Re: Proposed changes to SRFI-19 Marc Feeley 24 Apr 2000 14:45 UTC
> I prefer time-comparison names without terminal question marks. > I think these > (time= t1 t2) > (time< t1 t2) > are clearer than these > (time=? t1 t2) > (time<? t1 t2) > The terminal ? is redundant, hence unnecessary clutter. But so is string=?, char=?, etc. Here I prefer consistency with RnRS than independent elegance because you don't have to constantly wonder if you should add the question mark or not. (But I agree that dropping the ? is more elegant.) > You may wish to look at the scsh time spec, at the above URL. It has some > flaws, due to its close binding to the Posix API, but also has some > nice features. There are two time representations -- time (seconds), and > date (broken-out time -- y/m/d/h/m/s etc.) The API is quite simple: > (date) -> the current date (a struct) > (date tm [tz]) -> the date for time TM in timezone TZ > > (time) -> the current time (an integer) > (time dt) -> the time for date DT Except for the names (I would prefer (current-date) and (current-time)) and that time is represented concretely by an integer, I like this approach. To me a "time" object is an absolute point on the time line, and is independent of time zones, etc (and also independent of relativity but that's another topic...). A "date" object is really a representation of time that depends on local context (the time zone, daylight-savings time, etc). I see no problem in using a "time" object to program a deep-space probe, but would have a hard time using a "date" object... So I would suggest separating the two concepts in SRFI-19. Marc