Support for running vim commands

[tomtom]

It would be excellent if asynccommand#run() could also run arbitrary vim commands asynchronously. I'm thinking of something like:

    let env = {}

    function! env.get(temp_file) dict
        let qfl = eval(join(readfile(a:temp_file), "\n"))
        ...
    endf

    function! env.put(temp_file) dict
        let qfl = ...
        call writefile([string(qfl)], a:temp_file)
    endf

    call asynccommand#run("", env)

This would first run env.put() in the remote sub-vim to write some info to the tempfile, and then use
env.get() to retrieve the info.

[idbrii]

You'd only be able to use the results of those vim commands. The vim commands couldn't access any data from your current vim session. Do you have an example use case?

(You can already execute vim commands, but it's a bit awkward: AsyncShell gvim +"0,$s/e/r/g" +x c:/temp/somefile.txt. But if you want something like that, you should use ryanfmurphy/vimsed.)

[tomtom]

You'd only be able to use the results of those vim commands. The vim
commands couldn't access any data from your current vim session. Do
you have an example use case?

I needed this feature for the checksyntax plugin. IIRC I wanted to run
vim function that generates a quickfixlist based on the contents of some
file. I.e. instead of running an external compiler on a file, I wanted
to run a vim function. Anyway, it seems I found an alternative solution
for this problem.

[idbrii]

In that case, you'd need to invoke another vim process. It could take a file and output another file and then cat the output. Something like this:

AsyncShell gvim +"call ReplaceWithQuickfix()" +x c:/temp/somefile.txt ; cat c:/temp/somefile.txt

I could expose the vim executable to make that easier, but I don't think I'd want to include this as a built-in command. I don't want to give the impression that AsyncCommand can make vim functions run asynchronously (it's not a replacement for neovim's jobstart, it only operates on external processes). You won't have access to any other vim state and since vim isn't a filter (it doesn't output the result), you have to run cat vs type and other compatibility gotchas or write a custom handler that knows what file to load.

Regardless, I'm glad you found a solution.