Surround region with dollar sign ($) in Emacs - emacs

There is built-in emacs function for surrounding a region with parenthesis, as I found it here: https://stackoverflow.com/a/2952021/1635919. Is there an analogous way to surround a region with dollar ($)?
C-h f insert-pair tells that this function is able to surround sexp with any character, so how to bind surrounding with $ to M-$ as in the linked answer?
My Emacs: GNU Emacs 24.3.1 (i686-pc-linux-gnu, GTK+ Version 3.10.7)

You can duplicate what M-( does by looking at the insert-parentheses function. All it does is call insert-pair with hardcoded parameters, so you can analagously bind M-$ to the following function:
(defun insert-dolla-dolla-bills-yall (&optional arg)
(interactive "P")
(insert-pair arg ?\$ ?\$))

Set variable insert-pair-alist to include (?\$ ?\$):
(add-to-list 'insert-pair-alist (list ?\$ ?\$))
Then bind a key to insert-pair, to do what you want:
(global-set-key (kbd "M-$") 'insert-pair)

If you use the library YASnippet, it has built-in support for wrapping a surround region with custom code on either end of the selected region:
NOTE: It looks like the latest version of YASnippet has changed the name of the function from yas/selected-text to yas-selected-text. However, there appears to also be backwards compatible version.
# -*- mode: snippet -*-
# name: dollar-surround
# key: dollar-surround
# binding: C-I $
# --
$`yas/selected-text`$

There is a toolkit which delivers this alongside with a bunch of related one.
It's called ar-dollar-region-atpt
Get it here:
https://launchpad.net/s-x-emacs-werkstatt/

Related

How to Zoom in /out in emacs -nw (command line only) whithout having a numeric keypad (or mouse wheel)? [duplicate]

This s-expression in my .emacs file does not produce the desired result:
(define-key global-map (kbd "C-=") 'djhaskin987-untab-to-tab-stop)
Why can't I bind a command to Ctrl+=?
EDIT for clarification:
I am using emacs23-nox on the standard build of urxvt-256colors for Debian, except that I have recompiled with --disable-iso405776 (or something to that effect) it so that Ctrl+Shift doesn't do the weird 'insert character' thing. I don't know if this affects anything. For example, C-M-i sends M-TAB, which I don't understand.
EDIT II:
I apologize for not making this clear. The function djhaskin987-untab-to-tab-stop has the line (interactive) in it. This part works.
The accepted answer in combination with the link in the first comment to it is enough to get started on a complete solution. The steps are:
make your terminal output escape codes for the key
make Emacs recognise the escape codes as a standard keypress
bind the keypress in a mode map
The first is very terminal and/or operating system dependent.
The link in the first comment shows some examples for X Window System. The key names are available in /usr/X11R6/include/X11/keysymdef.h (or try locate keysymdef.h), prefixed with XK_ (which should be removed for our purposes). I read that symbolic names are preferred over key literals.
I don't currently run X but I think it should look like this in your case:
XTerm.VT100.Translations: #override \
Ctrl ~Meta ~Shift <Key> equal: string(0x1b) string("[emacs-C-=")\n
The first string is the escape, the second is of your choosing.
In iTerm you can use Preferences->Keys and choose Send Escape Sequence as the Action. For example, I have:
Emacs Wiki lists some configuration methods for other terminals.
Now you can teach Emacs to recognize it as a C-=. First define-key into input-decode-map. I have a couple of helper functions:
(defun my/global-map-and-set-key (key command &optional prefix suffix)
"`my/map-key' KEY then `global-set-key' KEY with COMMAND.
PREFIX or SUFFIX can wrap the key when passing to `global-set-key'."
(my/map-key key)
(global-set-key (kbd (concat prefix key suffix)) command))
(defun my/map-key (key)
"Map KEY from escape sequence \"\e[emacs-KEY\."
(define-key function-key-map (concat "\e[emacs-" key) (kbd key)))
So then:
(my/global-map-and-set-key "C-=" 'some-function-to-bind-to)
Some keys (currently: ()\|;'`"#.,) will need escaping in the string, like C-\..
In a terminal, TAB is represented by the same byte sequence as C-i. And typically the terminal has no special byte-sequence for C-=, so it will just send a =. There is nothing that Emacs can do about it. But you might be able to teach your terminal emulator to send some special byte sequence of your choice (check the documentation of your terminal emulator for that), after which you can teach Emacs to recognize it as a C-= (with something like (define-key input-decode-map "...thebytes..." [?\C-=])).
The problem is that you use emacs in the terminal.
The terminal does not allow "C-=".
Try your function in the graphical emacs and it will work.
You will have to find another keybinding for the terminal.
You can map C-= using the default ascii codes: ^[[61;5u. Then you can bind it in Emacs either using:
(global-set-key (kbd "C-=") 'djhaskin987-untab-to-tab-stop))
or let use-package do it, e.g.:
(use-package expand-region
:ensure t
:bind (("C-=" . er/expand-region)))
I do want to thank Sam Brightman, for his wonderful solution. It's a very clean, albeit heavy-handed, approach that will work for any keys that cannot be sent via normal ascii codes. I've been wanting to get C-TAB working inside iterm2 for a long time. I was able to do it by deleting the builtin preferences keys for C-TAB/C-S-TAB and using his approach. With the following, I can be ssh'd into remote Linux boxes and quickly switch through lots of open buffers in projects, just like a desktop editor.
(use-package nswbuff
:defer 1
:after (projectile)
:commands (nswbuff-switch-to-previous-buffer
nswbuff-switch-to-next-buffer)
:config
(progn
(my/global-map-and-set-key "C-TAB" 'nswbuff-switch-to-previous-buffer)
(my/global-map-and-set-key "C-S-TAB" 'nswbuff-switch-to-next-buffer))
:init
(setq nswbuff-display-intermediate-buffers t
nswbuff-exclude-buffer-regexps '("^ "
"^\*.*\*"
"\*Treemacs.*\*"
"^magit.*:.+")
nswbuff-include-buffer-regexps '("^*Org Src")
nswbuff-start-with-current-centered t
nswbuff-buffer-list-function '(lambda ()
(interactive)
(if (projectile-project-p)
(nswbuff-projectile-buffer-list)
(buffer-list)))))
The function you're binding must be interactive. Try:
(define-key global-map (kbd "C-=")
(lambda () (interactive) (djhaskin987-untab-to-tab-stop)))

redefine C-x C-e to evaluate custom language expression

I've defined a major mode for my language.
I'm trying to redefine C-x C-e so that when I'm in my major mode, it'd evaluate the expression using "my" custom interpreter.
Suppose my interpreter is just a command-line program that could be invoked like this:
$my-interpreter <some expression>
I imagine, all I need to do is to do a system call, passing the expression "before point" as argument and print the return value in the echo area.
How hard could it be, right?
Problem: I have no idea where to start!
Any hint?
Thanks.
You can take a look at shell-command and its relatives, along with thing-at-point. Here's a really simple example that uses an "interpreter" (just the shell echo command) to echo the word at point:
(defun my-interpreter ()
(interactive)
(let ((arg (thing-at-point 'word)))
(when arg
(shell-command (concat "echo " arg)))))
(Edit in response to comment.)
If you have defined a keymap for your major mode, you can bind C-x C-e in you major mode with a call to define-key. Otherwise, you can just bind it locally with (local-set-key (kbd "C-x C-e") 'my-interpreter).
It occurred to me that you might be interested in building in interactive functionality like a REPL. To do so, you might consider comint-mode; see the EmacsWiki and this post from Mastering Emacs to get inspired.

How do I bind C-= in emacs?

This s-expression in my .emacs file does not produce the desired result:
(define-key global-map (kbd "C-=") 'djhaskin987-untab-to-tab-stop)
Why can't I bind a command to Ctrl+=?
EDIT for clarification:
I am using emacs23-nox on the standard build of urxvt-256colors for Debian, except that I have recompiled with --disable-iso405776 (or something to that effect) it so that Ctrl+Shift doesn't do the weird 'insert character' thing. I don't know if this affects anything. For example, C-M-i sends M-TAB, which I don't understand.
EDIT II:
I apologize for not making this clear. The function djhaskin987-untab-to-tab-stop has the line (interactive) in it. This part works.
The accepted answer in combination with the link in the first comment to it is enough to get started on a complete solution. The steps are:
make your terminal output escape codes for the key
make Emacs recognise the escape codes as a standard keypress
bind the keypress in a mode map
The first is very terminal and/or operating system dependent.
The link in the first comment shows some examples for X Window System. The key names are available in /usr/X11R6/include/X11/keysymdef.h (or try locate keysymdef.h), prefixed with XK_ (which should be removed for our purposes). I read that symbolic names are preferred over key literals.
I don't currently run X but I think it should look like this in your case:
XTerm.VT100.Translations: #override \
Ctrl ~Meta ~Shift <Key> equal: string(0x1b) string("[emacs-C-=")\n
The first string is the escape, the second is of your choosing.
In iTerm you can use Preferences->Keys and choose Send Escape Sequence as the Action. For example, I have:
Emacs Wiki lists some configuration methods for other terminals.
Now you can teach Emacs to recognize it as a C-=. First define-key into input-decode-map. I have a couple of helper functions:
(defun my/global-map-and-set-key (key command &optional prefix suffix)
"`my/map-key' KEY then `global-set-key' KEY with COMMAND.
PREFIX or SUFFIX can wrap the key when passing to `global-set-key'."
(my/map-key key)
(global-set-key (kbd (concat prefix key suffix)) command))
(defun my/map-key (key)
"Map KEY from escape sequence \"\e[emacs-KEY\."
(define-key function-key-map (concat "\e[emacs-" key) (kbd key)))
So then:
(my/global-map-and-set-key "C-=" 'some-function-to-bind-to)
Some keys (currently: ()\|;'`"#.,) will need escaping in the string, like C-\..
In a terminal, TAB is represented by the same byte sequence as C-i. And typically the terminal has no special byte-sequence for C-=, so it will just send a =. There is nothing that Emacs can do about it. But you might be able to teach your terminal emulator to send some special byte sequence of your choice (check the documentation of your terminal emulator for that), after which you can teach Emacs to recognize it as a C-= (with something like (define-key input-decode-map "...thebytes..." [?\C-=])).
The problem is that you use emacs in the terminal.
The terminal does not allow "C-=".
Try your function in the graphical emacs and it will work.
You will have to find another keybinding for the terminal.
You can map C-= using the default ascii codes: ^[[61;5u. Then you can bind it in Emacs either using:
(global-set-key (kbd "C-=") 'djhaskin987-untab-to-tab-stop))
or let use-package do it, e.g.:
(use-package expand-region
:ensure t
:bind (("C-=" . er/expand-region)))
I do want to thank Sam Brightman, for his wonderful solution. It's a very clean, albeit heavy-handed, approach that will work for any keys that cannot be sent via normal ascii codes. I've been wanting to get C-TAB working inside iterm2 for a long time. I was able to do it by deleting the builtin preferences keys for C-TAB/C-S-TAB and using his approach. With the following, I can be ssh'd into remote Linux boxes and quickly switch through lots of open buffers in projects, just like a desktop editor.
(use-package nswbuff
:defer 1
:after (projectile)
:commands (nswbuff-switch-to-previous-buffer
nswbuff-switch-to-next-buffer)
:config
(progn
(my/global-map-and-set-key "C-TAB" 'nswbuff-switch-to-previous-buffer)
(my/global-map-and-set-key "C-S-TAB" 'nswbuff-switch-to-next-buffer))
:init
(setq nswbuff-display-intermediate-buffers t
nswbuff-exclude-buffer-regexps '("^ "
"^\*.*\*"
"\*Treemacs.*\*"
"^magit.*:.+")
nswbuff-include-buffer-regexps '("^*Org Src")
nswbuff-start-with-current-centered t
nswbuff-buffer-list-function '(lambda ()
(interactive)
(if (projectile-project-p)
(nswbuff-projectile-buffer-list)
(buffer-list)))))
The function you're binding must be interactive. Try:
(define-key global-map (kbd "C-=")
(lambda () (interactive) (djhaskin987-untab-to-tab-stop)))

Cannot get to bind Enter to 'newline-and-indent in Emacs !!! Very annoying

Cannot get to bind Enter to newline-and-indent in Emacs !!! Very annoying.
I already tried everything on the following thread by changing 'mode' to ruby and still nothing:
How do I make Emacs auto-indent my C code?
I know that the problem is the RETURN key, since if I bind to something else, works fine.
I tried [enter], (kbd "enter"), (read-kbd-macro "enter"), (kbd "RET")
Follow-up 1.
This is what I get from C-hkRET
RET runs the command newline, which is an interactive compiled Lisp
function.
It is bound to RET.
(newline &optional ARG)
Insert a newline, and move to left margin of the new line if it's blank.
If use-hard-newlines' is non-nil, the newline is marked with the
text-propertyhard'.
With ARG, insert that many newlines.
Call auto-fill-function' if the current column number is greater
than the value offill-column' and ARG is nil.
I dont know what to make of it or how to figure out if it's a global
or local binding that gets in the way. trying to remap C-j
also doesnt work.
As a previous comment says, use C-h k (describe-key) to see what the key is bound to at the point when it's not doing what you want. The (kbd "foo") syntax will be correct for whichever foo describe-key refers to it as.
Chances are that you are simply not defining that key in the appropriate keymap.
Note that major and minor mode keymaps take precedence over the global keymap, so you shouldn't necessarily be surprised if a global binding is overridden.
edit:
Myself, I have a hook function for common behaviours for all the programming modes I use, and it includes the sort of remapping you're after. The relevant part looks like this:
(defun my-coding-config ()
(local-set-key (kbd "RET") (key-binding (kbd "M-j")))
(local-set-key (kbd "<S-return>") 'newline)
)
(mapc
(lambda (language-mode-hook)
(add-hook language-mode-hook 'my-coding-config))
'(cperl-mode-hook
css-mode-hook
emacs-lisp-mode-hook
;; etc...
))
See Daimrod's answer for the explanation of why I'm re-binding RET to the current binding of M-j -- although I'm using comment-indent-new-line (or similar) instead of newline-and-indent (or similar), which does what I want in both comments and non-comments.
In Emacs 24, programming modes seem to derive from prog-mode, so you could probably (un-tested) reduce that list to prog-mode-hook plus any exceptions for third-party modes which don't yet do that.
As said earlier, use C-hkC-j because
C-j is the standard key to do newline-and-indent.
If you open a new file, activate ruby-mode and try the previous
command you will see why it doesn't work. Because ruby-mode doesn't
have newline-and-indent but rather
reindent-then-newline-and-indent. Yes that's stupid but you can either ask
to the maintener to change it, or accept it.
However I suggest you to use C-j to do it because
ruby-mode is not the only mode to do so, like paredit-mode which
uses paredit-newline.

OCaml Emacs Tuareg: Evaluate phrase keyboard shortcut, and how to display actual greek symbols?

Two questions about Emacs Tuareg for OCaml:
I have seen some configurations where it displays an alpha symbol instead of a'. How can I turn this on?
What is the keyboard shortcut for "evaluate phrase" or "evaluate buffer"?
I can only answer part (2):
To start an Ocaml top-level: C-c C-s
To evaluate a phrase: C-x C-e
To evaluate a buffer: C-c C-b
To evaluate a region: C-c C-r
Launch the tuareg mode (e.g. by M-x tuareg-mode), and look at its documentation pressing C-h m.
The symbols are displayed by the sym-lock mode only works for Xemacs and its variants I'm afraid, but you'll find how to configure it in your .emacs in the help mentioned above. The shortcut to execute a statement is C-x C-e (see section 'Special keys' of the help).
I'm not sure if this is exactly what you mean for part 1 of your question, but I have a font-lock-mode keyword to display the lambda keyword as the Greek lambda symbol, which could be adapted to do what you ask. It only requires that font-lock-mode be enabled. (I didn't write it, just found it floating around somewhere).
;; real lisp hackers use the lambda character
;; courtesy of stefan monnier on c.l.l
(defun sm-lambda-mode-hook ()
(font-lock-add-keywords
nil `(("\\<lambda\\>"
(0 (progn (compose-region (match-beginning 0) (match-end 0)
,(make-char 'greek-iso8859-7 107))
nil))))))
(add-hook 'emacs-lisp-mode-hook 'sm-lambda-mode-hook)
(add-hook 'lisp-interactive-mode-hook 'sm-lamba-mode-hook)
(add-hook 'scheme-mode-hook 'sm-lambda-mode-hook)
You can look to my existing configs, based on the code from EmacsWiki with some extensions - function to handle conversion from text to chars, and example of it use for erlang mode - you can change it for ocaml mode also
P.S. but this code has one disadvantage - it also displays these characters inside strings and comments