Irreal

Zachary Kanfer has a nice post on how to repeat a command with a single keystroke. A familiar instance of this is the old-style keyboard macro execution. After defining the macro, you can execute it with 【Ctrl+x e】 and then execute it additional times by simply typing 【e】. Kanfer wants to be able to do this for his own commands.

The trick is to use a transient keymap. Once you use a key in a transient keymap, the keymap goes away so the key will revert to its old meaning. This is a handy trick that’s useful in other circumstances too. For example, here is my code for invoking the ping utility in a full-frame buffer and then restoring the previous window configuration.

 1: (defun net-utils-restore-windows ()
 2:   "Restore windows and clean up after ping."
 3:   (interactive)
 4:   (kill-buffer (current-buffer))
 5:   (jump-to-register :net-utils-fullscreen))
 6: 
 7: (defadvice net-utils-run-program (around net-utils-big-page activate)
 8:   (window-configuration-to-register :net-utils-fullscreen)
 9:   (let ((buf ad-do-it))
10:     (switch-to-buffer buf)
11:     (delete-other-windows)
12:     (set-transient-map
13:       (let ((map (make-sparse-keymap)))
14:         (define-key map (kbd "q") 'net-utils-restore-windows)
15:         map))
16:     (message "Type \"q\" to restore other windows.")))

After the ping operation finishes and we’ve inspected the results, we want to restore the previous window configuration by typing 【q】. As shown on lines 12–15, we do that by defining a transient map. After typing 【q】 the transient map disappears and 【q】 reverts to simply being a letter.

Katherine Cox-Buday has a lovely 8-tweet long sequence in which she outlines how she uses Emacs to perform a periodic, tedious chore. It’s worth looking at to see if you can get some ideas from it. Here’s the last tweet in the sequence. (Click on the tweet to see the whole sequence.)

8/ And this is why I LOVE emacs. I can script my life. There are very few limitations. So yes, it is an OS, but that's a feature! #emacs <3!

— Katherine Cox-Buday (@katco_) September 3, 2016

What struck me, though, is her remark that “So yes, it is an OS, but that’s a feature!” I’ve always taken that joke to be a comment about Emacs’ editor function not an indictment that you can reasonably compare Emacs to an OS. I’ve also taken it as a given that yes, of course, it’s a feature.

That may be because I yearn for a Lisp Machine and Emacs gives me some semblance of that. On the other hand, how can you not like the fact that Emacs can do so much? What do you think? Is the fact that Emacs is like an OS a bug or a feature? You already know my answer.

UPDATE [2016-09-16 Fri]: also → always.

Ben Maughan over at Pragmatic Emacs has a nice tip for those of you using Emacs on OS X. It turns out that it’s easy to copy text to the kill ring with a mouse. I agree with Maughan that it’s not something I want because I try to avoid the mouse when I’m in Emacs but many people feel otherwise.

If you’d like to be able to easily copy text to the kill ring with a mouse, take a look at Maughan’s post to see how easy it is¹.

Back in January of 2015, I wrote about an excellent post from abo-abo on his refactoring workflow. If you haven’t read his post be sure to take a few minutes to read it. The basic idea was that he wanted to change all occurrences of an identifier in all files in a given directory. He does that by finding each occurrence with rgrep, making the rgrep result buffer writable with wgrep, then using iedit to change all occurrences at once.

Samuel Barreto has a similar workflow that uses counsel-ag. He uses the evil substitution command rather than iedit to make his change but that’s a detail. Take a look at his post for the details. If you’re using ag or looking for a reason to install it, his workflow is very appealing. I wouldn’t be surprised if abo-abo is using it himself now. If you often find yourself making this sort of global change, you really need to check out these workflows.

Grant over at Wisdom and Wonder has a short post that points us to imenu-list. That’s a minor mode that puts the output of imenu into a separate buffer where you may find it easier to work with. If you follow the link to imenu-list‘s GitHub page you can see a screen shot of it in action.

Somehow, I’ve never warmed up to imenu but perhaps this will help. You can think of imenu-list as being sort of like occur and use it in a similar way. If you find yourself jumping around a program buffer a lot, you may want to give imenu-list a try.

If you have files that you read in eww, here’s a suggestion that might make your workflow a bit easier:

(define-key dired-mode-map "e" (lambda () (interactive) (eww-open-file (dired-get-file-for-visit)))) e opens from #dired with #eww in #emacs

— ε (@goaoio) July 21, 2016