Re: Should mode commands be idempotent?

[Richard Stallman]

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  > But I think at least some here are talking about a
  > convention for Emacs _users_ to follow, e.g., for
  > 3rd-party code, not just for code distributed with Emacs.

Yes.

  > In that case, I don't see it as appropriate for an Emacs
  > convention to call out what constitutes a bug.

Sure it is.

We can't force anyone to follow our conventions.
We don't want to try to force anyone.

So we need not hesitate to state technical design conventions.
We can say that a non-idempotent mode is a bug.

  > 2. Beyond that, just what kind of "idempotence" is in
  > view?  What program state do we expect must be identical
  > if a mode is turned on more than once?  And what do we
  > mean by "identical" here?

That question sounds like a wild-goose chase.
I don't think we need to give it a precise answer.
"Enabling a mode should be idempotent" is enough to say.

-- 
Dr Richard Stallman
President, Free Software Foundation (gnu.org, fsf.org)
Internet Hall-of-Famer (internethalloffame.org)
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