Added: elixir-quoted-minor-mode

[sviridov]

Hi!

I'm a fan of macros and I really miss some slime or cider features about macro expansions in emacs-elixir.

So, this commit adds some interactivity for quoted expressions. Now, one can see a popup window with elixir highlighting and indentation instead of text message and close it with q.

[mattdeboard]

You are a man after my own heart.

Unfortunately this uses font-lock-ensure, which is not available in the latest stable release (24.4.50).

In order to check out the functionality (which is really cool!) I added the following to elixir-mode.el:

(defvar font-lock-ensure-function
  (lambda (_beg _end)
    (unless font-lock-fontified (font-lock-default-fontify-buffer)))
  "Function to make sure a region has been fontified.
Called with two arguments BEG and END.")

(defun font-lock-ensure (&optional beg end)
  "Make sure the region BEG...END has been fontified.
If the region is not specified, it defaults to the whole buffer."
  (font-lock-set-defaults)
  (funcall font-lock-ensure-function
           (or beg (point-min)) (or end (point-max))))

I also added the following line to the elixir-mode definition:

  (set (make-local-variable 'font-lock-ensure-function)
       'jit-lock-fontify-now)

Adding those made it work flawlessly.

I will be more than happy to merge this pull request if you can add a guard so that it's only activated if the user's emacs has font-lock-ensure available. Or perhaps adding e.g. elixir-compat.el with all the necessary additions to make this work.

I'm really excited about this (I am a fan of Clojure's emacs tooling as well) but can't merge it without guarantees for users that it will either work or be unavailable.

Thanks

Matt

[mattdeboard]

This could probably be accomplished through the use of functionp, e.g.

(when (functionp 'font-lock-ensure)
  (define-minor-mode elixir-quoted-minor-mode
  "Minor mode for displaying elixir quoted expressions"
  :group 'elixir-quoted :lighter " quoted"
  :keymap '(("q" . quit-window))
  (setq buffer-read-only t)))

[mattdeboard]

How does this look? 415dc6e...mdeboard-elixir-quoted-minor-mode

If that looks right, merge it into your branch and I'll merge the PR.

[sviridov]

Hi, Matt!

It's seems that there is no need in this call at all 😄. Looks like elixir-mode call already take care about fontification. So.. I just remove it.

[sviridov]

I took this idea of font-lock-<something> call from slime (here). But I didn't notice that they change font-lock-keywords-case-fold-search variable after setting major mode. So they really need to fontify buffer again, but we don't need it.

[mattdeboard]

👍