Re: guix completion in zsh

[Brice Waegeneire <brice@waegenei.re>]

Hello Reza,

On 2020-05-30 06:21, Reza Alizadeh Majd wrote:
> On Tue, 26 May 2020 23:14:01 +0200
> Ludovic Courtès <ludo@gnu.org> wrote:
> 
>> I think you need to make sure the Zsh completion file for Guix is
>> sourced.
>> 
> 
> Thanks for you response, what is the right location to find this "Zsh
> completion file"? is it installed during installation of `zsh` package?

I had the same issue since I switched to Guix but I didn't took the time 
to look into it before.

I just submitted a patch[0] that add
"/run/current-system/profile/share/zsh/site-functions" to $fpath, so 
system
packages will get completions. To get completions from user profile, I
added the following to my system configuration:

--8<---------------cut here---------------start------------->8---
(define %zshrc
   (plain-file "zshrc"
               "\
fpath+=($HOME/.guix-profile/share/zsh/site-functions)
"))

(operating-system
   …
   (services (list …
                  (simple-service 'zshrc etc-service-type
                    (list `("zshrc" ,%zshrc))))))
--8<---------------cut here---------------end--------------->8---

When $fpath is properly set, the user only have to run “autoload -Uz
compinit && compinit” or add it to it's '~/.zshrc' to enable 
completions.

I don't know how to add completions when using “guix environment”
especially when executed multiple times in a shell since 
GUIX_ENVIRONMENT
get replaced each time it's executed.

Also note that the ZSH completion for 'guix' has never been updated in 4
years so it's missing quite a few commands and options while 
'guix-daemon'
completion doesn't exists. So you get completions as nice as the ones 
from
bash.

I tried updating zsh's completions but I didn't went far because it's
tedious since it's a lot of copy pasting from “guix --help”. So to get
proper completion support for zsh a better solution would be to use the
bash completions as they are parsed from “guix --help” directly instead 
of
being copy-pasted and that zsh provide a bash compatible completion 
system
trough 'bashcompinit'. But unfortunately our bash completions have some
bashism that zsh can't understand, especially the 'compopt' built-in. 
You
can try to use bash completion in zsh by running “autoload bashcompinit 
&&
bashcompinit && source ./etc/completion/bash/guix” but you will end up 
with
half broken completions.

[0]: https://issues.guix.info/issue/41662

- Brice