From: Paul Eggert <eggert@cs.ucla.edu>
To: Eli Zaretskii <eliz@gnu.org>
Cc: larsi@gnus.org, andrewjmoreton@gmail.com, emacs-devel@gnu.org
Subject: Re: encode-time vs decode-time
Date: Tue, 6 Aug 2019 08:59:33 -0700 [thread overview]
Message-ID: <c2f8a879-3ed3-cb3d-7a8d-08c657bf490e@cs.ucla.edu> (raw)
In-Reply-To: <83blx2cr2o.fsf@gnu.org>
>> So now, as you suggested, encode-time has reverted to its old role
>> of converting from decoded timestamps to Lisp timestamps and its API is now simpler.
>
> Thanks, but judging by the changes in Lisp files all over, it sounds
> like this is a backward-incompatible change?
It's not as scary as it might first appear. The changes to the lisp/* files that
work around backward-incompatibility issues (by replacing (encode-time TIME
FORM) with (time-convert TIME FORM)) are needed only to fix Emacs internals code
that had already been changed to rely on Emacs 27 encode-time. Since Emacs 26
does not support (encode TIME FORM), users will not have to worry about making
these kinds of changes to their own code.
They only significant backward-compatibility issue I see is in the 2nd patch
("decode-time now returns subsec too"), which affects any user code that
requires (= 9 (length (decode-time))). I originally proposed extending
decode-time's API with a FORM option
<https://lists.gnu.org/r/emacs-devel/2019-07/msg00750.html> that would cause
decode-time to continue to behave as before unlless the given the new FORM
argument; this would default to current behavior and so would avoid the
backward-compatibility issue. However, Lars inspected uses of decode-time
<https://lists.gnu.org/r/emacs-devel/2019-07/msg00772.html> and found that they
invariably did something like (nth N (decode-time...)) or (apply #'encode-time 0
0 0 (nthcdr 3 (decode-time))). These uses will continue to work, so Lars
convinced me that his proposal to return a 10-element list was better. If you
prefer the more-backward-compatible approach I could look into redoing the time
code that way, though I expect it'll be a bit more hassle to document it and to
support it internally.
next prev parent reply other threads:[~2019-08-06 15:59 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-29 9:48 Support for sub-second time in decoded time Lars Ingebrigtsen
2019-07-29 14:03 ` Stefan Monnier
2019-07-29 14:12 ` Lars Ingebrigtsen
2019-07-29 14:43 ` Stefan Monnier
2019-07-29 15:00 ` Lars Ingebrigtsen
2019-07-29 17:50 ` Stefan Monnier
2019-07-30 11:33 ` Lars Ingebrigtsen
2019-07-29 16:08 ` encode-time vs decode-time Stefan Monnier
2019-07-30 10:32 ` Lars Ingebrigtsen
2019-07-30 11:34 ` Andy Moreton
2019-07-30 11:37 ` Lars Ingebrigtsen
2019-07-30 17:54 ` Paul Eggert
2019-07-30 22:50 ` Paul Eggert
2019-07-31 19:03 ` Lars Ingebrigtsen
2019-07-31 19:31 ` Stefan Monnier
2019-08-06 1:48 ` Paul Eggert
2019-08-06 14:21 ` Eli Zaretskii
2019-08-06 15:59 ` Paul Eggert [this message]
2019-08-06 18:23 ` Eli Zaretskii
2019-08-07 1:02 ` Paul Eggert
2019-08-07 2:41 ` Stefan Monnier
2019-08-07 14:47 ` Eli Zaretskii
2019-08-11 23:39 ` Lars Ingebrigtsen
2019-08-17 6:47 ` Paul Eggert
2019-08-07 11:33 ` Lars Ingebrigtsen
2019-08-17 7:54 ` Paul Eggert
2019-08-17 8:16 ` Eli Zaretskii
2019-08-17 9:33 ` Paul Eggert
2019-08-17 20:46 ` Lars Ingebrigtsen
2019-08-17 20:56 ` Paul Eggert
2019-08-17 21:42 ` Stefan Monnier
2019-08-17 22:53 ` Paul Eggert
2019-08-19 21:12 ` Stefan Monnier
2019-08-21 10:55 ` Adam Porter
2019-08-21 20:20 ` Paul Eggert
2019-08-26 10:59 ` Adam Porter
2019-08-26 21:35 ` Paul Eggert
2019-08-07 14:44 ` Eli Zaretskii
2019-08-07 11:41 ` Lars Ingebrigtsen
2019-08-17 9:25 ` Paul Eggert
2019-08-17 20:51 ` Lars Ingebrigtsen
2019-07-29 14:23 ` Support for sub-second time in decoded time Eli Zaretskii
2019-07-29 14:59 ` Lars Ingebrigtsen
2019-07-29 16:46 ` Paul Eggert
2019-07-30 11:43 ` Lars Ingebrigtsen
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