Re: on helm substantial differences

[Eli Zaretskii <eliz@gnu.org>]

> From: Juri Linkov <juri@linkov.net>
> Cc: spacibba@aol.com,  bugs@gnu.support,  andreyk.mad@gmail.com,
>   emacs-devel@gnu.org,  contovob@tcd.ie,  rudalics@gmx.at,
>   monnier@iro.umontreal.ca,  ghe@sdf.org,  drew.adams@oracle.com
> Date: Sat, 21 Nov 2020 22:18:08 +0200
> 
> >> FWIW, I like the old behavior better, since it shows completions in
> >> the "traditional" way: first the stuff I typed completed, then
> >> whatever else is relevant.  So maybe this should be an optional
> >> feature.
> 
> With the latest patch it's optional, enabled by 'completions-detailed',
> but an additional option could be added - specific to grouping only
> in read-char-by-name.
> 
> > Btw, just switching the order doesn't yet guarantee the names will
> > align, because characters are not guaranteed to have the same width on
> > display.  To really align them we need to use :align-to properties, or
> > at least TABs.  Of course, using those techniques we could also align
> > the display without switching the order...
> 
> This is a problem.  I tried TAB with tab-width=3, but some characters
> are still wider than 3.  Then I tried 'char-width' on these characters,
> but 'char-width' returns 1 for wide characters.  This is strange,
> I expected it to return 4 for characters wider than tab-width=3.

The result of char-width can only ever be 0, 1, or 2.  On GUI frames,
it doesn't always return the exact value, because characters can be
wider than 1, but narrower than 2.  But no character should be wider
than 2 columns.  Which characters did you see that required the width
of 3 or 4?