Complete stuff with Counsel

Intro

If you like my package swiper, I'm sure you'll also like counsel. It lives in the same repository, but you can install it separately from MELPA.

Counsel uses ivy - the same method as swiper to:

• Complete Elisp at point with counsel-el.
• Complete Clojure at point with counsel-clj.
• Open a git-managed file with counsel-git.
• Describe an Elisp variable with counsel-describe-variable.
• Describe an Elisp function with counsel-describe-function.
• Look up an Elisp symbol in the info with counsel-info-lookup-symbol.
• Insert a Unicode character at point with counsel-unicode-char.

Below, I'll describe the functions that I added just today.

counsel-describe-function

This is just a replacement for describe-function:

As you can see, regular expressions work here as well. The space-splitting behavior is the same as in swiper, so don't expect to be able to match a single space: spaces are wild.

counsel-describe-variable

This is just a replacement for describe-variable:

Well, actually I've used ido-mode with flx matching for these two functions before. In my experience, ivy handles much better:

• you are in charge of which regex you're searching for
• you see the candidate count
• no crazy wrap-around candidate cycling

And it works faster, too.

Here are my bindings:

(global-set-key (kbd "<f1> f") 'counsel-describe-function)
(global-set-key (kbd "<f1> v") 'counsel-describe-variable)

counsel-info-lookup-symbol

I don't use this one too often, but it's nice to have the option:

(global-set-key (kbd "<f2> i") 'counsel-info-lookup-symbol)

counsel-unicode-char

At around 40000 candidates, ivy starts to feel clunky (around 0.1s display delay). Unfortunately, I don't really see a way around this, except using tricks like while-no-input, which didn't work right when I tried it earlier. It would be really cool to do the completion in another thread, but alas.

Outro

Give the new functions a try. I think ivy can become a viable ido replacement, at least it has done so for me: the only ido functions that I'm still using are ido-switch-buffer and ido-find-file.

Also, if you're using projectile, you can use ivy completion for it:

(setq projectile-completion-system 'ivy)