Display the Keybinding for a Command with substitute-command-keys

If you ever need to show the keybinding for a particular command to the users of your package (e.g. you’re adding some tips functionality), you should avoid resisting the urge to write something like this:

(message "Press <C-c p p> to switch between projects.")

Why is this a bad idea? Because you might change the keybinding of the command in question (e.g. projectile-switch-project, but you might forget to update messages like this. Is there a better way? substitute-command-keys to the rescue:

(message (substitute-command-keys "Press <\\[projectile-switch-project]> to switch between projects"))

This will produce exactly the same message as before and you’re guaranteed the keybinding will always be in sync with the command.

Neat!

P.S. If you want to check interactively the keybinding of some command use C-h f (describe-function). Here’s an example - C-h f RET projectile-switch-project RET will produce this:

projectile-switch-project is an interactive compiled Lisp function.

It is bound to C-c p p, s-p p, <menu-bar> <tools> <Projectile> <Switch
to project>.

(projectile-switch-project &optional ARG1)

...

You can also check which command is bound to some key with C-h k.

Use Tab to Indent or Complete

By default in Emacs the Tab key does only indentation. If some major mode provides completion of some form, you normally have to trigger it with M-Tab. In most window managers, however, this keybinding is used to switch between open windows, which makes it a bit hard to use out of the box.

There’s a simple trick to augment the default Tab behavior. Just put this in your Emacs config:

(setq tab-always-indent 'complete)

Now, when you press Tab one time it will indent and if you press it again you’ll get completion candidates. If the indentation at point is already correct you’ll get the completion candidates right away. As an added bonus - you don’t really need M-Tab anymore.

Simple and neat! One really has to wonder why this isn’t the default behavior.

imenu-anywhere

For the longest time Prelude included the function prelude-goto-symbol (bound to C-c i). It basically allowed you to jump to any definition in the current source file using imenu behind the curtains.

Recently I’ve found an even better option - the package imenu-anywhere. It works in a pretty similar manner but gives you the ability to jump to any definition in any currently open buffer. That’s quite handy and it greatly reduces the need to use something like etags.

As an added bonus - imenu-anywhere features helm integration.

This is a very handy package and I encourage you to give it a go!

P.S. Prelude users should simply upgrade to the latest version of Prelude (it already uses it).

My Personal Emacs Configuration

From time to time people ask me about my personal Emacs configuration. Other just assume that I use Prelude. For a very long time my personal configuration was pretty similar to Prelude - in a way it was a staging ground for things to go into Prelude eventually (although changes would travel both ways when Prelude users suggest some cool things).

Recently I’ve decided that in the future I want to do a few things with Prelude:

  • extract as much functionality from it as possible into reusable packages (e.g. super-save and crux)
  • adopt there use-package
  • improve the support for Windows (because now I have Windows computer)

As part of these efforts I reworked my personal config into something pretty simple (it’s a single init.el file) and I’ve started experimenting with ideas for the future. Stay tuned for the results!

The config is available here. Perhaps some of you will find something useful there.

Remap Return to Control in GNU/Linux

A long time ago I wrote about remapping Return to Control in OS X. This was the best productivity boost for my Emacs experience ever!

Recently I’ve bought a Windows ultrabook (wanted something as light as MacBook Air, but more powerful and versatile) and I’m doing most of my work there in a Xubuntu VM. The first thing I did while setting up Xubuntu was to figure out how to do the aforementioned remapping.

In my original post some people suggested the tool xcape, so I took a look at it. The tool can certainly use some documentation improvements (and pre-built packages), but it gets the job done. After you’ve installed it you just need to add the following to your login shell’s init file (e.g. .bash_profile) and you’re in business:

xmodmap -e "remove Control = Control_R"
xmodmap -e "keycode 0x69 = Return"
xmodmap -e "keycode 0x24 = Control_R"
xmodmap -e "add Control = Control_R"

xcape -t 10000 -e "Control_R=Return"

Obviously the first time around you should source .bash_profile after updating it:

$ . .bash_profile

This is definitely a lot more work than just clicking in the GUI of the wonderful Karabiner, but it yields the desired results and that’s what’s important at the end of the day.

Now if only there was a way to achieve the same result in Windows…

P.S. vim users will love xcape. Its default behaviour is to generate the Escape key when Left Control is pressed and released on its own.