[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Should mode commands be idempotent?
From: |
John Wiegley |
Subject: |
Re: Should mode commands be idempotent? |
Date: |
Tue, 26 Sep 2017 11:54:44 -0700 |
User-agent: |
Gnus/5.130016 (Ma Gnus v0.16) Emacs/26.0 (darwin) |
>>>>> Drew Adams <address@hidden> writes:
> Good luck with such a guideline. The state of an Emacs session is _never_
> exactly the same after each time you turn on a mode - any mode, any session.
> So many things change...
I think we can reduce the scope of what we're saying:
The statement I made only applies if the command is called in immediate
succession. That is, the function is *itself* idempotent; it doesn't guarantee
that intervening effects are somehow negated.
That is, the following should be functionally equivalent:
(foo-mode 1)
(progn (foo-mode 1) (foo-mode 1))
I don't see what great difficulty this poses. If a mode author is doing thing
inside `foo-mode' like changing the system or the disk, that's exactly the
sort of thing our guideline seeks to prevent.
--
John Wiegley GPG fingerprint = 4710 CF98 AF9B 327B B80F
http://newartisans.com 60E1 46C4 BD1A 7AC1 4BA2
- Re: Should mode commands be idempotent?, (continued)
- Re: Should mode commands be idempotent?, Richard Stallman, 2017/09/25
- Re: Should mode commands be idempotent?, Clément Pit-Claudel, 2017/09/23
- RE: Should mode commands be idempotent?, Drew Adams, 2017/09/24
- Re: Should mode commands be idempotent?, Clément Pit-Claudel, 2017/09/25
- RE: Should mode commands be idempotent?, Drew Adams, 2017/09/25
- Re: Should mode commands be idempotent?, Stefan Monnier, 2017/09/25
- Re: Should mode commands be idempotent?, John Wiegley, 2017/09/25
- RE: Should mode commands be idempotent?, Drew Adams, 2017/09/26
- Re: Should mode commands be idempotent?, John Wiegley, 2017/09/26
- RE: Should mode commands be idempotent?, Drew Adams, 2017/09/26
- Re: Should mode commands be idempotent?,
John Wiegley <=
Re: Should mode commands be idempotent?, John Wiegley, 2017/09/19
Re: Should mode commands be idempotent?, Richard Stallman, 2017/09/20