How to specify standalone grouped up backends for either completion after idle or 'company-complete'

[IceAsteroid]

I know that both 'auto completion after idle' and company-complete both use the variable company-backends.

Now, I have a use case where I need only to show company-dabbrev-code for 'auto completion after idle' and have a keybinding bound to company-complete to show candidates provided by a list of grouped-up backends specified in company-backend variable.

The solution that I imagined is either

• be able to specific standalone grouped backends for company-complete & Company-backends for "completion after idle".
• be able to specific standalone grouped backends for "completion after idle" & company-backends for keybinding bound to company-complete.

How could it be done?

---

I have a workaround but it's not versatile because I found no way to group backends for either of the ways I described above.

    (add-hook 'haskell-mode-hook (lambda ()
				   ;; (setq-local company-backends
				   ;; 	       '((company-dabbrev-code
				   ;; 		  company-capf)))
				   ;; 		  :separate)))
				   (setq-local company-backends
					       '((company-dabbrev-code)))
				   (keymap-local-set "M-<tab>" (lambda ()
								 (interactive)
								 (company-abort)
								 (company-begin-backend 'company-capf)))
				   (interactive-haskell-mode 1)
				   (eglot-ensure)))

I've searched & browsed throught the issue & discussion pages & user manual for this, but found no answer.

[dgutov]

Hi!

This is non-trivial to do "properly", but some hacks might be within easy each. Let's try to establish the requirements.

Normally, when the user invokes company-complete or company-complete-common or company-next-completion, the completion turns from "idle" into "manual" one. But would you want the set of the backends used to switch as well? After each of these commands, or specific ones?

[IceAsteroid]

Good day, @dgutov. Sorry for the delay, I finally got some time.

Did you mean that the switch is done by the command company-other-backend, and it uses the variable company-backends to switch through?

If so, that's indeed a use case.

However, even when I set the company-backends lexically within a keybinding bound to company-backend, but invoking 'company-other-backend' will still not use the lexical variable as the list, as follows:

(keymap-local-set "M-<tab>" (lambda ()
						        (interactive)
							(company-abort)
						        (let ((company-backends '(company-dabbrev-code
											          company-capf)))
								   (company-complete))))

The message outputs "No other backend". In case to figure out, I've also set several backends outside the lexical, switching is fine with "completion after idle", I don't know what's going on.

---

And I've managed to group backends into one with :separate keyword for a keybinding, with lexical binding, like the following:

(keymap-local-set "M-<tab>" (lambda ()
							(interactive)
							(company-abort)
							(let ((company-backends '((company-dabbrev-code
											            company-capf :separate))))
								   (company-complete))))

It's nice if there's a way for company-other-backend to be used to switch a list of backends for a keybinding.

In my use cases, I'm rarely using it, I'm mostly using the "grouped backends with :separate" feature.

[dgutov]

Did you mean that the switch is done by the command company-other-backend, and it uses the variable company-backends to switch through?

I didn't mean that command in particular (yes, it's a separate command), but it can be added to the mentioned list, yes.

However, even when I set the company-backends lexically within a keybinding bound to company-backend, but invoking 'company-other-backend' will still not use the lexical variable as the list, as follows:

You are not using company-other-backend in both snippets, though. They both include calls to company-complete - it's a different command.

It's nice if there's a way for company-other-backend to be used to switch a list of backends for a keybinding.

That command switches to the next configured backend in company-backends (the one after the currently used one). Is that the effect you were looking for?

[IceAsteroid]

I meant, to have the standalone backend list to switch, specifically for the completion via a keybinding, itself separated from the "company-backends" that's widely used by things like the "completion after idle".

Normally, when the user invokes company-complete or company-complete-common or company-next-completion, the completion turns from "idle" into "manual" one. But would you want the set of the backends used to switch as well? After each of these commands, or specific ones?

But in my attempt of the configuration, I wasn't able to successfully achieve it. I'm not very good at elisp, I'm sorry.

I was invoking the company-other-backend during the popup of completion tooltip launched by the keybinding that's defined to have a let expression to have the lexical scope "company-backends" bound in it, and company-complete in it.

Like what I posted:

(keymap-local-set "M-<tab>" (lambda ()
						        (interactive)
							(company-abort)
						        (let ((company-backends '(company-dabbrev-code
											          company-capf)))
								   (company-complete))))

But company-other-backend outputs: No other backend.

I'm sorry for the unclear explanation.

[dgutov]

I was invoking the company-other-backend during the popup of completion tooltip launched by the keybinding that's defined to have a let expression to have the lexical scope "company-backends" bound in it, and company-complete in it.

Indeed, the let-binding like in your example set a value that is restored at the end of a command. So any later commands that look up company-backends again won't see that value.

If you want to use it with company-other-backend, you could create a similar wrapper command for it, which would also temporarily set company-backends to a value like the above.

[IceAsteroid]

@dgutov, fine, thank you for the patience :)

[dgutov]

Speaking of your workaround solution, the backend argument can be a list too.

So you can try calling (company-begin-backend '(company-capf company-dabbrev-code)), for example.

[IceAsteroid]

Hi, dgutov, grettings!

Thanks for the solution. It looks nice. I'm gonna respond your first comment and try out the solution in the second command later.