Emacs / Slime Key Binding / Sending command to Swank Server - emacs

I'm familiar with scheme, but new to emacs (switching over from VIM) and elisp.
I know how to do the following:
make a simple key binding
C-c iwb = indent whole buffer
F2 = turns folding on/off
use slime from emacs
some basic keys, like C-x 2, paredit keys, some basic movement keys
I need help doing something a bit more advanced:
I want F3 to equal:
put emacs into C-x 2 mode
in bottom window, switch to "slime-repl" buffer
in the "slime-repl" buffer, send the command "(test/run)" <-- note, this is meant to be sent to the swank server, NOT to elisp
I realize it's terrible form to ask people to write a script for me; however, if anyone could do that, I would learn rather quickly from it. [And it would allow me to do more complicated types of scripting through studying your example.]
Thanks!

This is not exactly what you want, but should be a good starting point for further tweaking:
(defun slime-run-test ()
(interactive)
(slime-interactive-eval "(test/run)")
(slime-pop-to-buffer (slime-output-buffer) t))
(global-set-key (kbd "<f3>") 'slime-run-test)

I don't use slime, but assuming it uses comint-mode then I would think the following might do the trick:
(defun my-slime-test-run ()
(interactive)
(delete-other-windows)
(split-window-below)
(with-selected-window (next-window)
(switch-to-buffer "slime-repl")
(goto-char (point-max))
(insert "(test-run)")
(comint-send-input)))
(global-set-key (kbd "<f3>") 'my-slime-test-run)
There is probably a better way to do this, but hopefully that gives you a little insight into how you can write elisp functions to carry out tasks in the editor (and note how the function reads very much like a set of editor instructions -- you can do a lot simply by converting the keystrokes you would use into equivalent code -- or even not writing code at all, and simply recording & saving keyboard macros).
Use C-hf name-of-the-function RET to get documentation on any of the function/macro calls in that function.
For the keybinding, I used C-hkF3 to check how Emacs referred to that key, and then used that string as the argument to kbd (and note how you can use that sequence to find the name of the function bound to any given key sequence, which you can then utilise in code if desired).
Many things are far less obvious if you don't already know them, but that's only to be expected with a code base as large as this (and dating back as long as this).
The great thing is that if you don't know what you're looking for, you can always search for function names matching patterns with C-uC-ha (and similarly for variables, values, libraries, and documentation; see M-: (info "(emacs) Apropos") RET for more about this facility). Plus the info manuals (complete with indexes -- press I or i within any particular manual, or use the info-apropos command to search all info manuals at once).
Truly one of the very best things you can do is to learn how to use the self-documenting nature of Emacs to find answers to the things you don't already know.

Related

Better defaults for emacs

I've been using Vim for a several years. And now I want to give a try to Emacs.
For Vim I have a general config file (here) where I'm overriding defaults (e.g. hey, Vim, show me the line numbers; save more history, don't create these stupid backup files, etc...)
I want the same thing for Emacs. While searching, the best thing I've found is better-defaults.el from technomancy. I'm still digging in Prelude and Emacs-Starter-Kit sources, but there are too many overrides and plugins.
So, what I want:
ability to see a list of variables, which I can customize (e.g. indent-tabs-mode or newline-and-indent). I know about C-h v variable-name but this command requires me to know a name of variable, but I want a list of them
sample config file for Emacs which sets helpful defaults with comments for each command
For your first question: M-x customize-option.
C-h v TAB is not what you want, as it shows you also non-option variables (e.g., internal variables).
However, if you load library help-fns+.el then C-u C-h v TAB shows you only the user options (in buffer *Completions*).
My advice would be to not look for an existing "sample config file", if you intend to start with it, as opposed to just seeing how another user redefines things. And for help with the latter, I would still recommend the Emacs manual over looking at someone elses init file. Especially to start with.
However, if you really want to look at init files from other users then this is the place to start. (And this is a good place to start, other than the manual (which is the best place), to learn about customizing Emacs.)
Finally, my (unsolicited) advice wrt learning Emacs, including customizing, is to start by not customizing it at all. I say that without irony as one who has heavily customized Emacs.
If you want to "get it", i.e., to get a feel for the Emacs design and what makes it different, then let yourself get used to Emacs as it is out of the box -- for maybe a month or so. At that point you can think about customizing, and your customizations are likely to be much wiser (in your own terms, i.e., for whatever it is that you want).
Another way of putting this is that until you know Emacs a bit, you really do not know what it is that you want or need in terms of customization. In particular, it would be a mistake, IMO, to start out by trying to think of Emacs in terms of Vim or trying to make Emacs do what you've done in Vim. There is plenty of time for that later, if, based on understanding Emacs, you really do want to do that.
Welcome to Emacs. Enjoy.
I'm going to take a reasonable dissent from Drew's excellent answer, there are some things you really ought to set in your emacs-file immediately, that aren't set out of the box that you really ought to set.
Issue number 1: THAT $(generate-swearing) BELL!
The bell will ding like a madman. That's annoying. You can turn it off.
In your init-file, do this:
(setq visible-bell 1)
Issue number 2: Emacs has an interesting view of backup files.
If you edit a file, say "foo.txt", emacs will create little backups of the file with the name "foo.txt~" in the same directory.
This is annoying as all hell, and you can fix it by doing this:
(setq backup-directory-alist '(("" . "~/.emacs.d/emacs-backup")))
Issue number 3: Emacs uses C-w differently than bash does, and that's a bit annoying.
C-w usually deletes a word backwards. By standard in emacs, it deletes the marked region. That's a bit silly.
It is better to do something like this:
;; This is my preference, your mileage may vary.
(global-set-key (kbd "C-x C-k") 'kill-region)
(global-set-key (kbd "C-x k") 'kill-buffer)
(global-set-key (kbd "C-w") 'backward-kill-word)
Issue number 4: Alt-X is a clunky way of running an interactive command.
It is better to do something like this instead, avoid your hand cramping up all the time.
(global-set-key (kbd "C-x C-m") 'execute-extended-command)
(global-set-key (kbd "C-x C-m") 'execute-extended-command)
You also may want to check out Steve Yegge's Effective Emacs: https://sites.google.com/site/steveyegge2/effective-emacs
It's pretty amazing. One thing to note though is that the caps-lock to ctrl thing is also available through a microsoft tool here:
https://learn.microsoft.com/en-us/sysinternals/downloads/ctrl2cap
This is better than the manual hack Yegge suggests, and you can turn it off if you don't like it.

function similar to other-buffer but with filtering

I'm looking for a way to include some filtering in the other-buffer method in emacs.
Currently calling other-buffer pulls up the last most recent buffer, but the problem with this is that buffers that get modified by external processes keep coming up as other-buffer. I would like to implement some sort of filtering in other-buffer.
Currently I use evil with C-^ bound to other-buffer, and I have some tail.el buffers active, and when I try to switch bufffers the tail buffers keep popping up.
Is there some alternative to other-buffer or could someone scratch up some code to implement this, Thanks.
What has worked for me is winner-mode - it's like an undo, but for window configurations.
Here's my setup:
(winner-mode)
(global-set-key (kbd "<f7>") 'winner-undo)
(global-set-key (kbd "C-<f7>") 'winner-redo)
Also I'd recommend other-window on some very cheap shortcut, since it's
a command that's used a lot.
I've put it on C-p, since I didn't appreciate the inconsistency
that one of the direction keys is so far away from others.
I've got previous-line on C-h instead, so now
my direction keys are n h f b - they're almost together!
And I didn't really miss the defaults on C-h, since f1
has the same functionality.
Ok so I got some workable solution but its not perfect it using bits from this answer:
emacs lisp, how to get buffer major mode?
(defun buffer-mode (buffer-or-string)
"Returns the major mode associated with a buffer."
(with-current-buffer buffer-or-string (format "%s" major-mode)))
(defun other-buffer-ex ()
(interactive)
(switch-to-buffer
(if (string-equal (buffer-mode (other-buffer)) "comint-mode")
(next-buffer) (other-buffer))))

Emacs Macro to Start in Shell Mode and Run a Command

I have a confession: I don't know Lisp. Despite that fact, with a bit of help from some co-workers, I managed to write an emacs macro/script which:
switched to shell mode (ie. M-x shell-mode)
disabled truncating lines (ie. M-x toggle-truncate-lines)
started a database console (ie. "mysql")
I was then able to start emacs with that macro using the --script option, and suddenly I had a way to start mysql in a much friendlier environment with a single command :-)
But here's the problem: I changed jobs and left that script behind. Now I'd very much like to re-create that script at my new job, but I no longer have any emacs experts to help me write it like I did at the old job.
Now, I really hate SO posts where someone basically says "please write my code for me", so I don't want to do that. However, if any emacs macro experts could at least give me some pointers (like "here's how you invoke a M-x command in a macro"), or point me to an emacs-macro-writing guide, or otherwise "teach me to fish" on this issue, I would greatly appreciate it.
... and if someone just happened to have a similar script already lying around that they wanted to post, I certainly wouldn't complain ;-)
Most emacs commands (i.e., M-x toggle-truncate-lines) can be translated directly to elisp by wrapping them in parentheses:
(toggle-truncate-lines)
The rumours are true, in lisp you just scatter parentheses around and they make magic.
Now in this case, you can do better. Toggling makes sense for an interactive function, but in a program you don't really want to toggle truncate-lines, you want to turn on truncate-lines. Its the same thing if truncate-lines was turned off to begin with, but you don't know when your program will be run next. Anyways, in Emacs, features are often controlled by a variable. In this case, the variable is truncate-lines, and to turn that feature on, you set the variable to t (which means true).
To do this, use:
(setq truncate-lines t)
We use setq instead of = for assignment, because they made lisp before = had been invented.
For the real scoop you should take a look at Robert Chassel's excellent "An introduction to to Programming in Emacs Lisp". It comes built-in with your emacs, you can get to it with C-h i m Emacs Lisp Intro.
A good way (I think) to start writing elisp functions is to record keyboard macros, and then to analyse them using edit-kbd-macro
For example, if you start recording a keyboard macro using f3, then do interactively all the things you want and terminate the macro using f4, you can see the underlying emacs-lisp commands using M-xedit-kbd-macrof4 (this last f4 is the key binding you'd have used to execute the keyboard macro)
<<shell>> ;; shell
<<toggle-truncate-lines>> ;; toggle-truncate-lines
mysql ;; self-insert-command * 5
RET ;; comint-send-input
Now you can write a script using these functions, looking up the documentation (e.g. C-h ftoggle-truncate-lines) to see if you should call them with special arguments in non-interactive mode.
You should also replace self-insert-command by calls to insert.
This should give you something like the following script, which you can call using emacs --load myscript.el
(shell)
(toggle-truncate-lines 1)
(insert "mysql")
(comint-send-input)
Of course, this might not work as expected the first time, so you might have to eval (setq debug-on-error t) to get debugging information.
What version of Emacs are you using?
In Emacs 24, I have M-x sql-mysql, which does everything you ask and has font-locking.

Emacs define-key, Viper-mode key binding

I'm trying to learn emacs, getting vi custom key bindings.
Using Viper-mode, what is the correct way to re-bind a key? (I'm using Colemak keyboard layout(instead of qwerty) so have to change things like n->j) But would like it to work in viper-mode.
From this key binding guide on GNU.org:
http://www.gnu.org/software/emacs/manual/html_node/viper/Key-Bindings.html
It says the command to put in your .viper file is:
(define-key viper-vi-global-user-map "\C-v" 'scroll-down)
It doesn't work for me... in fact not sure I even have the function "define-key"...
M-x define-key [No match]
I'm not sure if 'define-key' is available on my version of emacs?
This works, but not in viper-mode
(global-set-key "n" "j")
Any help would be much appreciated. This is my first day using Emacs, to it's a pain getting Colemak & Viper-mode to work properly.
Thank for any help...
Hopefully some useful answers here:
First, having that line in the .viper works for me. Note that the viper-vi-global-user-map applies when you're in command mode, not insert mode.
Secondly, define-key isn't a command, it's a regular function, which just means that it cannot be called using M-x. See this Emacs wiki page for a little more detail on that distinction. But that was a good attempt.
Third, the global-set-key is a command, you could have tried making a change using M-x global-set-key. But, that sets the key in the current global map, which isn't the same as viper-vi-global-user-map. Viper-mode uses a bunch of different keymaps to make Emacs behave like vi, but all of the maps are overlaid on top of the global map.
I'm guessing that you found that C-v wasn't bound like you want when you're in insert mode. And that can be solved by adding this to your .viper:
(define-key viper-insert-global-user-map "\C-v" 'scroll-down)
Lastly, scroll-down may not be what you want. The down refers to the text moving down (given the perspective of a fixed window). C-v is generally bound to 'scroll-up. But,maybe it is exactly what you want.
Caveat: I'm not a viper-mode user, I don't even know how to use vi. So my terminology may be off. But I find the challenge of changing things in viper-mode very interesting.
Edited to add
From your comment it sounds like you want n to be the same as what j is bound to by default. Try adding this:
(define-key viper-vi-global-user-map "n" 'viper-next-line)
In "normal" mode I did M-x describe-key j, which told me that j is bound to 'viper-next-line, and the above line will bind n to the same routine. Repeat for the rest of the bindings you want to shift around.
in modern times evil-mode is the vim emulation layer for emacs, and to tweak it for colemak, my https://github.com/wbolster/evil-colemak-basics package helps a lot.

Does Emacs has word and line completion (like Vim's insert mode completion)?

Vim completes words and lines with CTRL-X P and CTRL-L. There's a Emacs plugin called Company mode but this plugin interfere and cause conflicts with lots of things within Emacs (with global linum and yasnippets). I know that I can complete words with CTRL-/ in Emacs. But it is possible to take previously written lines to complete code?
Maybe you're looking for hippie-expand? From that web page (as of this writing, anyway):
HippieExpand looks at the word before
point and tries to expand it in
various ways including expanding from
a fixed list (like expand-abbrev),
expanding from matching text found in
a buffer (like dabbrev-expand) or
expanding in ways defined by your own
functions. Which of these it tries and
in what order is controlled by a
configurable list of functions.
For a comprehensive list of completion options visit the emacs wiki page on completion.
There are a gazillion ways to do completion in Emacs. Some are mode specific, some inline, some configurable and what not. Here is a list of modes that might help you.
Use numberic argument to complete by line, say M-5 M-/ will complete by line, while M-/ alone still complete the normal way.
hippe-expend function has a very useful feature which is :
With a positive numeric argument, jumps directly to the ARG next function in this list. With a negative argument or just C-u, undoes the expansion.
Customize the expansion functions in hippie-expand-try-functions-list and put the function try-expand-line as 5th list element, then you could use M-5 M-/ to complete by line.
This tip is very handy and useful and I highly recommend it.
Also worth noting: if your window manager does not steal Alt-tab, emacs will auto-complete with Alt-tab (I set up my window manager to user the "windows key" instead of alt for this very reason).
If you are using evil, this is the most vim-like solution I use:
(defun my-expand-lines ()
(interactive)
(let ((hippie-expand-try-functions-list
'(try-expand-line-all-buffers)))
(call-interactively 'hippie-expand)))
(define-key evil-insert-state-map (kbd "C-x C-l") 'my-expand-lines)
This way you can use our old friend C-x C-l in insert mode for whole line all buffers completion.
Thanks #ymln for the suggestion of using try-expand-line-all-buffers.