Re: [Emacs-diffs] scratch/widen-less a4ba846: Replace prog-widen with consolidating widen calls

[Dmitry Gutov]

On 12/2/17 11:47 PM, Stefan Monnier wrote:

> Since Eli only wants MMM-support if it work 100% everywhere, I don't
> think it matters what gets into Emacs itself in this respect, because
> the real stuff will have to live elsewhere.

But we need prog-first-column in Emacs. Except it already is. >_<

> The thing we should try and fight for of course are those such as making
> indent-according-to-mode widen before calling indent-line-function.

Right. That's true for many major modes already, though.

> I'm glad English includes enough redundancy that you could make out what
> I meant.

:-)

> The idea is just to highlight those lines whose indentation would be
> modified by indent-line-function, so you only want to compute the
> target column and compare it with the current column.

I still don't see how you're going to compute the target column without 
calling the indentation function. That's why switching to a non-mutating 
function will help.

> > > Arguably `smie-indent-functions` already provides that functionality.
> > As an example, yes, but it's not like we can move all modes to SMIE.
>
> Hence the "arguably": it can be used without using SMIE, but it's not as
> convenient as you might like.  E.g. you can do:

Yeah... Let's not do that. Generic code won't really be able to rely on 
this practice anyway.

> > > BTW, could we get some kind of multi-mode package in elpa.git or
> > > emacs.git to go along with that (it doesn't have to be fancy, but it's
> > > important that it doesn't have any submode-specific hacks).
> > Do you have any particular hacks in mind, in e.g. mmm-mode?
>
> No.  Can we put mmm-mode into elpa.git?

I'll try emailing the original authors again. The last time I did that 
there were no replies, unfortunately.