Re: Stealing minibuffers [Was: Confused by y-or-n-p]

[Eli Zaretskii]

> Date: Sat, 09 Jan 2021 09:34:26 +0000
> From: Gregory Heytings <ghe@sdf.org>
> cc: Eli Zaretskii <eliz@gnu.org>, stefankangas@gmail.com,
>         monnier@iro.umontreal.ca, rudalics@gmx.at, emacs-devel@gnu.org,
>         juri@linkov.net
> 
> 1. Start with the old code / behavior
> 
> 2. Carefully refactor that code to make the implicit behavior explicit, 
> and to make room for other possible behaviors
> 
> 3. Add other behaviors

That isn't always possible in software engineering.  Sometimes you
need to throw away the old code and rewrite it from scratch, using
what you perceive as the requirements as your guide.  For example,
when the old code was written based on some restriction that you want
to lift, it can be impractical refactoring the code if too many of its
parts have that restriction implicitly hard-coded in the algorithm.

I've bumped into this a couple of times when I made the Emacs display
engine support bidirectional text.