I'd like to rebind
C-up to "M-p : bring the previously entered expression down to the prompt"
and
C-down to "M-n : bring the expression after the current expression in the expression history down to the prompt"
Racket behaves differently from my default terminal where I can use these control bindings to scroll through previous expressions. The racket manual gives some examples of rebindings but does not explain how to rebind a key only in the interactions window which is what is needed here. What it's doing is keeping the same binding for C-up & C-down to mean move the cursor up and down, as is useful in the editor window, in the interaction prompt. But I don't think I want that as I can't see the use of it.
This is what I have for my own use. Feel free to adapt it:
#lang s-exp framework/keybinding-lang
(require drracket/tool-lib)
(define (register-repl key command command-fallback)
(keybinding key (λ (ed evt)
(define canvas (send ed get-canvas))
(send (send ed get-keymap) call-function
(if (is-a? canvas drracket:unit:interactions-canvas%)
command
command-fallback)
ed evt #t))))
(register-repl "d:up" "put-previous-sexp" "beginning-of-file")
(register-repl "d:down" "put-next-sexp" "end-of-file")
Related
I have installed Emacs under Windows 7 and want to use it in my everyday work. Unfortunately Emacs world and other text editors world are completely different and I am getting stuck on every third sequence of keys pressed on keyboard - it's doing something that I don't expect it would do.
I want to make a panic command - when I press ESC ESC ESC it stops doing everything, quitting from minibuffer, stops entering command, unhighlight regexps, etc. It already does what I want, except it killing buffers, the layout of my workspace. So I modified keyboard-escape-quit function in simple.el file (found it by C-h k ESC ESC ESC)
(defun keyboard-escape-quit ()
"Exit the current \"mode\" (in a generalized sense of the word).
This command can exit an interactive command such as `query-replace',
can clear out a prefix argument or a region,
can get out of the minibuffer or other recursive edit,
cancel the use of the current buffer (for special-purpose buffers),
or go back to just one window (by deleting all but the selected window)."
(interactive)
; Stop highlighting regexp
(unhighlight-regexp)
(cond ((eq last-command 'mode-exited) nil)
((region-active-p)
(deactivate-mark))
((> (minibuffer-depth) 0)
(abort-recursive-edit))
(current-prefix-arg
nil)
((> (recursion-depth) 0)
(exit-recursive-edit))
(buffer-quit-function
(funcall buffer-quit-function))
;((not (one-window-p t))
; (delete-other-windows))
((string-match "^ \\*" (buffer-name (current-buffer)))
(bury-buffer))))
I have byte-compiled and loaded this file and it works ok. But I can't figure out why it is not loading at startup.
You cannot modify some special built-in libraries, including simple.el. Emacs never actually loads these special libraries from their source or byte code files. Their byte code is directly included in the Emacs executable at build time, by a process called “dumping”. Emacs loads these libraries from its own binary.
Generally, should not modify any built-in libraries anyway. Your risk breakage, and your customizations are lost when you update Emacs.
Instead, do what you are supposed to do: Add custom functions to your init.el.
Hence, instead of modifying the built-in keyboard-escape-quit, create your own function, e.g. my-emergency-quit, in your init.el, and bind it to a global key, e.g. C-c q, with
(global-set-key (kbd "C-c q") #'my-emergency-quit)
Some final words of advice: I do not think that such a panic command does any good. The first rule of Emacs is: Don't panic. If you are stuck, don't try to quit and kill everything. Rather, try to find out why you are stuck, and how to get “un-stuck” by normal means. You'll learn Emacs better this way, imho.
I'm trying to define my own shortcuts for DrRacket.
I created the file necessary to make C-Z as undo (it's C-_ or C-x;C-u in emacs Keybindings) :
#lang s-exp framework/keybinding-lang
(keybinding "c:z" undo)
However, nothing happens when I add it to keyboards shortcuts.
What did I miss ?
a) You can enable C-Z, C-X, C-V, C-C, etc. editing style by checking "Enable keybindings in menus" in Edit>Preferences>Edition>General.
b) If you want only this particular binding to work, try with:
(keybinding "c:z" (lambda (editor evt) (send editor undo)))
You may need to restart DrRacket (not sure).
With DrRacket,v6.0 on Windows7, I want to change the keybinding "c:/" to "tab", and use "Complete Word" as in the Edit menu.
I followed these instructions to write a file but it does not work.
Here is my file's code:
#lang s-exp framework/keybinding-lang
(define (rebind key command)
(keybinding
key
(λ (ed evt)
(send (send ed get-keymap) call-function
command ed evt #t))))
(rebind "tab" "Complete Word")
I added it to the keybindings but nothing happens when I press the tab key.
Can anyone tell me why?
Use auto-complete instead:
(keybinding "tab" (λ(editor event) (send editor auto-complete)))
Finding the correct functions for keybinding is a bit of a trial and error process, to my experience. The function names as written in the menu "Edit/Keybindings/Show active keybindings" (approximate translation from French) are not always the correct ones it seems.
In particular, here it is written "Word completion" but it does not seem to work for me, whereas "TeX compress" does work (but has a different function).
I'm using Emacs in conjunction with AucTeX (running Ubuntu 10.04, if that matters).
Does anyone know if there is a way to automatically enable LaTeX-math-mode (a minor mode of AucTeX) if the point is in any maths environment (i.e. in a $...$, a $$...$$, begin{equation}...\end{equation}, and so on)?
I suppose there is a relatively easy answer, since syntax highlighting uses the same criterion for coloring math stuff, but I could not find anything.
If andre-r's answer doesn't satisfy you, here's some code that sets up ` to self-insert in text mode and act as a math mode prefix in math mode. LaTeX-math-mode must be off.
(defun LaTeX-maybe-math ()
"If in math mode, act as a prefix key for `LaTeX-math-keymap'.
Otherwise act as `self-insert-command'."
(interactive)
(if (texmathp)
(let* ((events (let ((overriding-local-map LaTeX-math-keymap))
(read-key-sequence "math: ")))
(binding (lookup-key LaTeX-math-keymap events)))
(call-interactively binding))
(call-interactively 'self-insert-command)))
(define-key LaTeX-mode-map "`" 'LaTeX-maybe-math)
The following improvements are left as exercises:
Make it a minor mode.
Make it more robust towards unexpected input (I've only tested basic operation).
Show a better error message if the user presses an unbound key sequence.
Show help if the user presses C-h or f1.
LaTeX-math-mode is "a special minor mode for entering text with many mathematical symbols." (For those who don't know how, you press e.g. `A and get \forall.) So I guess it doesn't hurt to leave it on, also if you're not entering maths.
The info page therefore suggests:
(add-hook 'LaTeX-mode-hook 'LaTeX-math-mode)
IMHO the only downside would be that you have to press the prefix twice: `` to get `, at least that works with the standard prefix ` customized in LaTeX-math-abbrev-prefix.
Most emacs modes include some sort of prefix to activate their features. For example, when using GUD "next" is "C-c C-n". Of these modes, many provide special buffers where one can use a single key to activate some functionality (just 'n' or 'p' to read next/previous mail in GNUS for example).
Not all modes provide such a buffer, however, and repeatedly typing the prefix can be tiresome. Is there a well-known bit of elisp that will allow for ad-hoc specification of prefix keys to be perpended to all input for some time? (Until hitting ESC or some other sanctioned key, for example)
I agree with Joe Casadonte's answer that the way to go is to define your own minor (or major) mode.
That being said, your question is interesting.
Here's a solution that prompts you for a key sequence and it takes the prefix keystrokes and promotes that keymap to the top level.
e.g. Assume the following keymap:
M-g ESC Prefix Command
M-g g goto-line
M-g n next-error
M-g p previous-error
When you run M-x semi-modal-minor-mode, it will prompt you for some keystrokes. If you enter M-g n, then the following keybindings are set:
ESC Prefix Command (same as M-g ESC)
g goto-line
n next-error
p previous-error
So now n doesn't self-insert, but jumps to the next error. See the code below.
Note: when this minor mode is enabled, <f12> is bound to a command which disables the minor mode. This is because the keybindings might very well disable your Emacs (for instance, what if there was a new keybinding for M-x).
Edited to add these thoughts: the minor mode variable was originally made buffer local, but that doesn't work unless you also make the minor-mode-alist variable buffer local (duh). But, you also (probably) don't want these bindings in the minibuffer... So, I'm not going to test it b/c it really depends on what you want, but I've added a comment to the code reflecting this thought.
Without further ado:
(defvar semi-modal-minor-mode-keymap (make-sparse-keymap)
"keymap holding the prefix key's keymapping, not really used")
(defvar semi-modal-minor-mode-disable-key (kbd "<f12>")
"key to disable the minor mode")
(defun semi-modal-minor-mode-disable ()
"disable the minor mode"
(interactive)
(semi-modal-minor-mode 0))
(define-minor-mode semi-modal-minor-mode
"local minor mode that prompts for a prefix key and promotes that keymap to the toplevel
e.g. If there are bindings like the following:
M-g ESC Prefix Command
M-g g goto-line
M-g n next-error
M-g p previous-error
And you enter 'M-g n' when prompted,
then the minor mode keymap has the bindings
g -> goto-line
n -> next-error
p -> previous-error
ESC -> Prefix Command (same as M-g ESC)
The variable semi-modal-minor-mode-disable-key is bound to disable the minor mode map.
This is provided because often the mappings make the keyboard unusable.
Use at your own risk."
nil " Semi" semi-modal-minor-mode-keymap
(make-local-variable 'semi-modal-minor-mode)
(make-local-variable 'minor-mode-map-alist)
(let ((pair-holding-keymap-to-modify (assq 'semi-modal-minor-mode minor-mode-map-alist)))
(setcdr pair-holding-keymap-to-modify (make-sparse-keymap))
(if semi-modal-minor-mode
(let (key
keymap)
;; all but last (b/c we want a prefix
(setq key (substring (read-key-sequence "Enter a full key combination, the prefix will be used: ") 0 -1))
(if (and (not (equal "" key))
(not (equal (kbd "C-g") key))
(let ((semi-modal-minor-mode nil))
(keymapp (setq keymap (key-binding key)))))
(progn
(setcdr pair-holding-keymap-to-modify (copy-keymap keymap))
(when semi-modal-minor-mode-disable-key
(define-key (cdr pair-holding-keymap-to-modify)
semi-modal-minor-mode-disable-key 'semi-modal-minor-mode-disable)))
(semi-modal-minor-mode 0))))))
The mode-specific (modal?) part of key-bindings in Emacs is realized by the various local maps that overshadow the universal global-map. Most major and minor modes define their own local maps; for example, there is a gud-mode-map. Key bindings in a local keymap will be activated only when the current-buffer is in the respective mode. You can customize a mode specific keymap through the mode's hook. For example, you may put this snippet into your ~/.emacs
(add-hook 'gud-mode-hook
(lambda ()
(local-set-key (kbd "C-n")
(lookup-key (current-local-map) (kbd "C-c C-n")))))
More details about keymaps can be found in Elisp reference manual.
The basic issue here is that there is no current keymap per-se. There's the global keymap which is overridden by the major mode's keymap which in turn is overridden by one or more minor mode keymaps (and they can step on each other in some defined way, I'm sure). Defining a new major mode will still leave the minor mode keys functional, and defining a new minor mode will only affect whatever keys you define in the minor mode's keymap.
For example, you could define a minor mode that will do what you want as long as the minor mode is active. You define a new minor mode my-gud-mode which will have its own keymap. You would then have to define all of your key mappings for it (e.g. n, p, etc) and you would also have to define all of the keys that you didn't want to work to be bound to the function ignore. That's the real pain of this, remapping all of the other keys. The minor mode is easy to switch on and off, though; that's the advantage.
Defining a new major mode would be easier at first blush, as it will let you override more of the "current keymap" in one shot. It should note the current major mode in a buffer-local variable so it can be restored later when the temporary major mode is turned off. But you'll still have other minor modes intruding into your keymap, so it won't be "pure".
What I do in this situation is define an easier prefix! For stuff I use all of the time, all day every day, I give them a function key all on their own (e.g. I have F1 set aside as my jabber-mode key). For less immediately useful things, I have two other function keys set aside, F3 and F12 (I'm sure there was some reason I picked them long ago, but I no longer remember why). F3 defines keys that are always available, regardless of major mode. F12 defines keys that are major-mode-dependent. Some examples:
I have set up F3-m- as a prefix to switch major modes (e.g. F3-m-p switches to cperl-mode) and F3-M- as a prefix for minor modes (e.g. F3-M-v toggles view-mode). These are always available, so you could do something like bind F3-g- to be your gud prefix, and type F3-g-p for previous and so on.
My F12 key is mode-dependent. So, in dired mode F12-e will call dired-nt-open-in-excel on the current file, and in emacs-lisp-mode F12-e will call elint-current-buffer. Somehow I never get them confused.
If you need help in defining keymaps like this, let me know.
Viper mode allows you to map commands to keys or key sequences while in the visual mode (entered using the "esc" key). Go back to insert mode with "i".
Have a look at viper-in-more-modes.elIt uses viper-modify-major-mode.
I also like to use the viper-vi-global-user-map: a snippet from my .emacs file.