Re: Variable-width font indentation

["Clément Pit-Claudel" <cpitclaudel@gmail.com>]

On 2018-03-06 15:31, Eli Zaretskii wrote:
>> Cc: emacs-devel@gnu.org, eggert@cs.ucla.edu
>> From: Clément Pit-Claudel <cpitclaudel@gmail.com>
>> Date: Tue, 6 Mar 2018 14:59:21 -0500
>>
>> * Paul and I have been discussing an language-agnostic heuristic to preserve alignment when changing from monospace to variable-pitch faces.  This intends to preserve the original indentation of the code, by inferring what it would have been if the logic originally used to indent the document had been aware of variable-pitch faces.
> 
> I don't see a need for such a feature, sorry.  We have indentation
> already; its only problem is that it doesn't work well with variable
> pitch fonts.  That's what we need to try to fix, if we care about the
> capability of displaying program code with such fonts.

I'm thoroughly confused: doesn't the algorithm that Paul proposed, and that I show an implementation of, do exactly that?

Do you want to get the indentation code involved because the heuristic isn't perfect?
 
>> * You're describing a language-specific way to get a nice-looking variable-pitch rendering of a document; your way is to reindent the document, essentially.
> 
> I was describing a way of teaching the existing indentation code
> handle variable-pitch fonts.

Right, which is where we differ: the solution Paul and I have been thinking is designed not to rely on exiting indentation facilities. 

In your world, concretely, what happens when I open xdisp.c and press M-x variable-pitch-mode? Does everything look misaligned until I M-x indent-region the whole file?

What about a file from a different project that uses a different indenting convention?

Thanks,
Clément.