Efraim Flashner <efraim@flashner.co.il> writes:

> On Sun, Sep 20, 2020 at 11:57:58PM +0300, Efraim Flashner wrote:
>> On Sun, Sep 20, 2020 at 09:50:12PM +0200, Ricardo Wurmus wrote:
>> > 
>> > Efraim Flashner <efraim@flashner.co.il> writes:
>> > 
>> > > On Sun, Sep 20, 2020 at 09:29:27PM +0200, Ricardo Wurmus wrote:
>> > >> 
>> > >> Efraim Flashner <efraim@flashner.co.il> writes:
>> > >> 
>> > >> > diff --git a/gnu/packages/aux-files/guix.vim b/gnu/packages/aux-files/guix.vim
>> > >> > new file mode 100644
>> > >> > index 0000000000..ca97f451d8
>> > >> > --- /dev/null
>> > >> > +++ b/gnu/packages/aux-files/guix.vim
>> > >> > @@ -0,0 +1,7 @@
>> > >> > +" This appends all of the vim plugins to the end of Vim's runtimepath.
>> > >> > +for directory in ["/run/current-system/profile", $HOME . "/.guix-profile", $GUIX_ENVIRONMENT]
>> > >> 
>> > >> How about using $GUIX_PROFILE as well or instead of $HOME/.guix-profile?
>> > >> This would allow users to keep a separate profile for Vim things.
>> > >
>> > > That was the one part I didn't really like about my patch. Unfortunately
>> > > I don't seem to have $GUIX_PROFILE set on my machine.
>> > >
>> > > (ins)efraim@E5400 ~$ echo $GUIX_PROFILE
>> > >
>> > > (ins)efraim@E5400 ~$
>> > 
>> > Me neither!  But when loading profiles we suggest this approach:
>> > 
>> >    export GUIX_PROFILE=/the/location/of/the/.guix-profile
>> >    source $GUIX_PROFILE/etc/profile
>> > 
>> > The variable is set in that case, because that affects whether absolute
>> > store file names are used or the symlink
>> > “/the/location/of/the/.guix-profile”.
>> 
>> It seems to be the case for the default profile. And in Guix System. I
>> could also just add $GUIX_PROFILE as another location in the list of
>> directories to search.
>
> The more I think about it the more I see $HOME/.guix-profile as a
> "special profile" which is nearly always included in $PATH and other
> variables, similar to /run/current-system/profile. With that in mind I
> like the attached patch which keeps that path but adds a search for
> $GUIX_PROFILE.
>
> I could use environment variables to override vim's builtin search for
> $VIM and $VIMRUNTIME, but then we would have to decide to support vim
> installed by the user or system-wide.

So vim only expects a single vimfiles directory in those variables?

[...]

> +++ b/gnu/packages/aux-files/guix.vim
> @@ -0,0 +1,7 @@
> +" This appends all of the vim plugins to the end of Vim's runtimepath.
> +for directory in ["/run/current-system/profile", $HOME . "/.guix-profile", $GUIX_PROFILE, $GUIX_ENVIRONMENT]
> +    let vimplugins = directory . "/share/vim/vimfiles"
> +    if isdirectory(vimplugins)
> +        let &rtp = join([&rtp,vimplugins], ',')
> +    endif
> +endfor

I wonder if we could generalize this to a proper search path with
something like (pseudo code):

  for directory in getenv("VIM_PLUGIN_PATH").split(":")
    let vimplugins = directory . "share/vim/vimfiles"
    ...

And then in the vim package:

(native-search-paths
 (list
  (search-path-specification
   (variable "VIM_PLUGIN_PATH")
   (files '("share/vim/vimfiles")))))

...which makes Guix populate VIM_PLUGIN_PATH automatically as plugins
are added to a profile/environment (as long as it contains the 'vim'
package).

WDYT?