GNU bug report logs - #5852
23.1; Incorrect references in ses-mode

Previous Next

Full log

Message #44 received at 5852 <at> debbugs.gnu.org (full text, mbox):

From: Stefan Monnier <monnier <at> iro.umontreal.ca>
To: Vincent Belaïche <vincent.belaiche <at> gmail.com>
Cc: Stefan Kangas <stefan <at> marxist.se>, Lars Ingebrigtsen <larsi <at> gnus.org>,
 Vincent Belaïche <vincentbelaiche <at> orange.fr>,
 5852 <at> debbugs.gnu.org, Göran Uddeborg <goeran <at> uddeborg.se>
Subject: Re: bug#5852: 23.1; Incorrect references in ses-mode
Date: Fri, 30 Jul 2021 17:01:29 -0400

> are run sequentially in the command loop : post-command hook of
> command N does not overlap command N+1, please confirm …

That's usually true, yes.  There can be exceptions when command N itself
can run commands during execution, via a recursive command-loop
(e.g. query&replace uses that, or minibuffer interactions).

> Now, I have another speculation : SES gets the current cell from the
> cursor position by reading some buffer text property
> 'cursor-intangible.  I speculate that the radix of the bug is that when
> a command sets this cursor property, then the buffer is actually
> modified in the backgroun, and the change may not be yet in effect
> when the next command runs.  Could you confirm / infirm this
> speculation.

Hmm... no that doesn't sound right.  Emacs does try to do a few things
in the background, but it's quite limited (things like `font-lock`,
basically).  When a property like `cursor-intangible` is set, it
happens immediately.

> One more thing is the following : in SES the cursor-intangile property
> is the symbol corresponding to the cell object (which under the hood
> is a vector), not the cell object itself. This means that the property
> has to change when there are row/column insertion / deletion, which
> also inherently change the buffer, because of symbol relocation. I
> think this might be some bad design choice, and pointing directly at
> the cell object would have saved some troubles (and probably would
> also create a bunch of other problems, so do not take my statement for
> sure).

Indeed, pointing directly at the cell's vector would probably be better
(at least from the point of view of insertions/deletions but), but if
so, each cell would probably need to contain its own name (or its
coordinates).


        Stefan

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.