Re: Lisp primitives and their calling of the change hooks

[Eli Zaretskii]

> From: Stefan Monnier <address@hidden>
> Cc: address@hidden,  address@hidden
> Date: Fri, 05 Jan 2018 17:28:15 -0500
> 
> > Maybe I don't understand what are we trying to accomplish with these
> > changes, and that's why I fail to see why the proposed changes are for
> > the better.
> 
> The current text basically says "don't rely on them being balanced" but
> doesn't say what the coder can rely on if he wants to share information
> between a-c-f and b-c-f.
> 
> The new text tries to be sufficiently loose that if Emacs doesn't obey
> it it's actually a bug, yet sufficiently precise that an Elisp coder
> can make use of it to reliably share information between a-c-f and
> b-c-f.

Can you describe a practical situation where an Elisp coder could use
the new text to some practical benefit, i.e. to change her
implementation to be better/more resilient (as opposed to just
enhancing her understanding of this stuff)?  I guess I don't see how
such practical benefits would be possible with the new text.