Add shell completions for bash/fish/zsh and add executables to path

[SamuelMiksits]

Yay I created shell completion! This adds the following:

• forsyde-devtools-exe and forsyde-lsp-exe to PATH. This makes it so you can run forsyde-devtools-exe directly without the usage of cabal exec forsyde-devtools-exe -- and having to manually type that out because cabal exec does not tab match.
• Shell completion for bash/fish/zsh for options inside those 2 executables.

How it works

The file /.completions/generate_completions.sh is a bash script that generates completion scripts for bash/fish/zsh automatically. I created this since we might want to have this as a pre-commit hook or an automatic build task in the future so that we don't manually have to rerun it.

Then, in the nix flake I use the following

# Add completion script
source .completions/forsyde-devtools-exe/$0
source .completions/forsyde-lsp-exe/$0

where $0 retrieves the name of the current shell. This is where I am not entirely sure. If I run this in a "normal terminal" I get for instance:

$ echo $0
/bin/bash 

but if I run this inside nix develop I get:

$ echo $0
bash 

But if this can only be ran inside nix this should probably be fine? Then it should only be bash or zsh or fish without the /bin/ part in front of it.

Also, sorry, I couldn't help myself. I changed chmod +x .git/hooks/* to chmod u+x .git/hooks/* and didn't undo it before I commited, I can edit it back if you want.

Test

Start with

$ nix develop

from the root of forsyde-devtools. This should add forsyde-devtools-exe and forsyde-lsp-exe to PATH.
Then, try to enter forsyde-devtools-exe by typing

forsyde-d<TAB>

which should automatically shell complete to forsyde-devtools-exe.
Try that this also works with:

forsyde-l<TAB>

which should automatically shell complete to forsyde-lsp-exe.
Then, try to complete some options in the executable such as --output-forsyde-ir with

forsyde-d<TAB> --output-f<TAB>

which should complete to forsyde-devtools-exe --output-forsyde-ir.

Also, try that it works for the LSP with:

forsyde-l<TAB> --p<TAB>

which should complete to forsyde-lsp-exe --port.

[SamuelMiksits]

@sthaeron You use zsh right? So would be good if you could test it for that

[SamuelMiksits]

Converted to draft since I was having some issues. When I try to pass a file it can't find it which is kind of a problem
(EDIT: Okay seems like it works, but the issue is that bash completion for arguments doesn't work, since it is not enabled by default. This can be fixed by adding action:

-- Handle file input, always need to define a file
inputFile :: Parser Input
inputFile =
  InputFile
    <$> strArgument
      ( metavar "INPUT"
          <> help "Input filename"
          <> action "file"
      )

When I run this in my normal bash it works fine, but when I run in Nix I get

bash: line 1: compgen: command not found

this is typically a problem when you are in a non-interactive shell so I am stuck troubleshooting that right now)

[SamuelMiksits]

Hmm, I guess it uses my "PWD" so it puts literally my path in there

[klarasm]

Ah, yes. After replacing that with my own path it worked for me.

[SamuelMiksits]

I guess the intention is that you should re-generate this script by running

$ ./.completions/generate_completions.sh

inside NixOS from the root forsyde-devtools/. My general problem is that the wiki for optparse-applicative says the following:

For a quick test, you can run something like (for a program called foo on the PATH):

$ source <(foo --bash-completion-script `which foo`)

Normally, the output of --bash-completion-script should be shipped with the program and copied to the appropriate directory (usually /etc/bash_completion.d/) during installation.

and I don't understand how I can ship this script with our project unless the binary is in like /usr/bin or something (since which resolves the path to something on my home path).

I can't really figure out how to get a PATH to our binary inside the bash completions that can calculate itself, that we can actually ship. Like do we literally have to put $(pwd) inside the completion scripts ourselves? I can put a command that runs the .completions/generate_completions.sh inside the Nix shell hook, but the issue is that we don't know if the binary exists yet when you do that (on first time clone of the repo I don't expect it to be built), so the which command would probably error out.

[ramadhanafif]

This is cool

[SamuelMiksits]

@sthaeron Now I have updated it so that you can autocomplete file paths for arguments, for both the compiler and LSP server. So this means that now you can do:

forsyde-devtools-exe --o<TAB>-f<TAB> ./e<TAB>m<TAB>S<TAB>03<TAB> --s<TAB>

(I mean you can technically also autocomplete the forsyde-devtools-exe binary)
to get to

forsyde-devtools-exe --output-forsyde-ir ./examples/model/SDF_example_003.hs --stdout

where it was previously not possible to autocomplete the path to the model. So we can leave this for now and revisit it once we have a real shippable binary.