Re: dir-local vs major-mode setting

[Phil Sainty]

On 2018-11-15 11:19, Stefan Monnier wrote:
> I'm thinking of a case where the project says "you should use TABs" so
> it sets
>
>     ((nil . ((indent-tabs-mode . t))))
>
> in the .dir-locals.el file.  But TABs in TeX files tend to behave
> funny, so tex-mode.el sets indent-tabs-mode to nil.  Assuming the
> .dir-locals.el setting was meant for "the majority of the files"
> and those aren't .tex files, it would make sense to favor the major
> mode's setting for the few .tex files.

If the project is expected to contain .tex files then the above would
constitute a bug in the .dir-locals.el file (which should contain mode-
specific entries for exceptions to the global settings).

Users could either fix the .dir-locals.el file, or add their own
custom .dir-locals-2.el file with the necessary overrides.

They can also use `hack-local-variables-hook'.


> I guess sometimes you want one and sometimes you want the other.
> So maybe to handle that case we'd want to introduce another wildcard
> that works like the `nil` above but implies it's applied before running
> the major mode's setup function.

If a "hack certain local vars before running hooks" facility was added,
I wouldn't think it should be constrained to the nil case?

Perhaps add something like the string path syntax, under which you
can provide a complete dir-locals spec, which should run early.  The
key might be a keyword like :early or some such.


-Phil