In some code, I want to set the mark.
The documentation for set-mark-command says,
With C-u C-u as prefix argument, unconditionally set mark where point is.
So how do I call set-mark-command in this way?
EDIT: I see I should be using push-mark instead, in this particular case. But the general question of how to provide a double-prefix argument programmatically remains.
Like this:
(set-mark-command '(16))
Small explanation to find this info:
f1 f set-mark-command
jump to definition in simple.el from the *Help* window.
C-uC-M-x will call eval-defun with a prefix argument, which instruments the code for debugging when the function is called.
C-u C-u M-x set-mark-command.
You should now be in the debugger. e arg will give (16).
See C-hig (elisp) Prefix Command Arguments RET
Related
I am using emacs with the major mode "Java/L Abbrev" activated. When I type M-x comment-region or M-x uncomment-region the desired effects happen in the editor. But I am getting tired of typing this out every time.
I have found that I can type C-c C-c and comment a region. I want to find a similiar way to uncomment a region. I go to the emacs docs:
https://www.gnu.org/software/emacs/manual/html_node/ccmode/Comment-Commands.html
And it says to give the C-c C-c command a negative argument to uncomment lines. How do I do this? or is there a better way?
Please try M-;, which is bound by default to comment-dwim. I think this should do what you want.
comment-dwim (DWIM stands for "Do What I Mean") is bound to M-; by default and works differently depending on whether or not the region is active (and sometimes what mode you're in)
From the emacs help page for comment-dwim:
comment-dwim is an interactive compiled Lisp function in
‘newcomment.el’.
It is bound to M-;.
(comment-dwim ARG)
Call the comment command you want (Do What I Mean).
If the region is active and ‘transient-mark-mode’ is on, call
‘comment-region’ (unless it only consists of comments, in which
case it calls ‘uncomment-region’).
Else, if the current line is empty, call ‘comment-insert-comment-function’
if it is defined, otherwise insert a comment and indent it.
Else if a prefix ARG is specified, call ‘comment-kill’.
Else, call ‘comment-indent’.
You can configure ‘comment-style’ to change the way regions are commented.
Your question is how to use C-c C-c to uncomment the region.
#AaronHarris answered your question about using a negative prefix arg.
But I think you misread the doc of comment-region (which CC mode binds to C-c C-). It does not uncomment the region. It deletes a certain number of comment characters.
To uncomment the region you use C-u - a plain prefix arg (no explicit number) to uncomment the region. C-h f comment-region says:
comment-region is an interactive compiled Lisp function in
newcomment.el.
It is bound to menu-bar edit region comment-region.
(comment-region BEG END &optional ARG)
Comment or uncomment each line in the region.
With just C-u prefix arg, uncomment each line in region BEG .. END.
Numeric prefix ARG means use ARG comment characters.
If ARG is negative, delete that many comment characters instead.
The strings used as comment starts are built from comment-start
and comment-padding; the strings used as comment ends are built
from comment-end and comment-padding.
By default, the comment-start markers are inserted at the
current indentation of the region, and comments are terminated on
each line (even for syntaxes in which newline does not end the
comment and blank lines do not get comments). This can be
changed with comment-style.
So the answer is to use C-u C-c C-c.
And FWIW, comment-region is much better than M-; (comment-dwim) for commenting and uncommenting the region. It lets you nest and unnest comment blocks any number of levels.
TLDR: Use C-- C-c C-c; i.e., prefix your command with "control-hyphen"
To give a negative argument to a command, you need to call either the negative-argument command or the universal-argument command, supplying a negative argument. (Try C-h f for more information on these.)
The negative-argument command is bound to keys C--, M--, and C-M--, so all of these will work as prefixes; generally, you'll use the one that's most convenient to type for any given command.
The universal-argument command is bound to C-u and accepts its argument immediately after that, so you can also do C-u -, optionally followed by zero or more digits (e.g., C-u - 5 3 9); that one is overkill here, but good to know about.
Finally, here is the section of the Emacs manual that discusses this topic.
Why not mapping the uncomment-region command to a key? It's not really what you were asking for (previous answer are better for this) but it's a way to stop typing M-x uncomment-region every time
like this (with the key binding you want)
(global-set-key (kbd "C-c C-u") 'uncomment-region)
Documentation about key binding can be found here:
Commands for Binding Keys
Customizing Key Bindings
Here is a map of command:
Map of command
You can use C-h k (M-x describe-key) to show what command is bind to a particular key (so you're sure to not erase it) and C-h f (M-x describe-function) will show you a description of the function + its binding.
First, select the region
To comment, use
ALT + x comment-region
To un-comment, use
ALT + x uncomment-region
Credits: https://www.reddit.com/r/emacs/comments/1kklgl/command_to_uncomment_entire_comment_block/
I would like F5 to switch to the most recently used buffer. This functionality is accomplished by running M-x icicle-buffer and then hitting enter to not specify the buffer I want to switch to -- (the default behavior of icicle is to switch to the most recent buffer.)
I have tried editing my .emacs thus:
(defun most-recent-buffer-please ()
(interactive)
(icicle-buffer " "))
(global-set-key [(f5)] 'most-recent-buffer-please)
but when I evaluate this lisp, and then hit F5, I get an error that starts with Wrong number of arguments followed by a lot of gibberish characters. What am I doing wrong?
A function can have mandatory and/or optional arguments, or no arguments at all. When writing elisp, it is usually a good idea to find out what arguments are available for certain functions by typing M-x describe-function RET [name of the function] RET. Drew (the author of Icicles) has indicated in his comment underneath the original question that the function icicle-buffer is not designed to be used in conjunction with any arguments -- therefore, adding " " causes the error message that the original poster experienced.
To switch to the previous buffer, Emacs already has a built-in function called previous-buffer. Since the original poster has indicated a preference for the f5 key, the following is an example of how to configure that keyboard shortcut so that it triggers previous-buffer -- brackets are sufficient and the parentheses used by the original poster around f5 can be omitted:
(global-set-key [f5] 'previous-buffer)
When I want to find the command bound to C-u M-. using C-h k, it turns out that emacs gives me the command bound with C-u. What should I do ?
C-u is provides a prefix argument to the function called after it (as you can see from its docs). Access the documentation for M-. and then look there for what happens when the function receives a prefix argument. There's no separate documentation for C-u M-. since it is not separate function.
For example, if I want to comment this:
(defun noop ()
nil)
Every time I try to put a semicolon before the "(defun", the defun runs away to the next line. So how is that supposed to be done?
GNU Emacs 23.1.1
Edit: by "running away" I mean when I insert a semicolon before "(defun", a newline is automatically inserted after the semicolon and "(defun" starts on a new line again.
See the command M-x comment-region and related.
M-X comment-dwim or M-;, which is the default key binding for the former — might save you a few key strokes, since it not only comments, but uncomments region, if it's commented already. Anyway, check out Emacs Manual for a proper description.
Ron, do a CTRL-H m and look at the minor modes. You have some "helpful" minor mode active. (Maybe paredit but I dont think that's it.) I remember there was something like that when I tried the EMACS Starter Kit. It lasted maybe thirty seconds before I screamed and found how to kill it.
In any case, that's not default EMACS behavior, it's some init-file or site-emacs addition.
Mark both lines and call M-x comment-region. Also look at comment-or-uncomment-region and comment-dwim functions.
For the specific task you asked for in the headline (commenting a complete expression that may span multiple lines at once), first press C-M-SPC (bound to mark-sexp) to set the region to the expression following point, and then M-; (bound to comment-dwim which will call comment-region).
If you're talking about Common Lisp (rather than, say, Emacs-Lisp), you can use #+(or):
#+(or)
(defun noop ()
nil)
See the CLHS for details.
a little late to the party, however, what about:
(defmacro comment (&rest a))
(defvar orgCmntEnd nil "Org Comment End")
(defun orgCmntBegin (<comment <commentEnd))
(orgCmntBegin "
** orgCmntBegin. Permits us to include * at the beginning of line as a comment.
Which in turn allows us to switch between emacs-major mode and org-mode for COMEEGA.
Example usage is:
(orgCmntBegin \"multi-line comment comes here.\" orgCmntEnd)
I wish elisp had a here-document facility. Like common-lisp.
Anybody listening?
" orgCmntEnd)
I'm trying to use C-h c in emacs to figure out what a key combination is bound to. The combination is C-u C-c C-q, which realigns tags in org-mode. However, Emacs just tries to look up C-u C-c and then fails. What am I doing wrong? I realize I could easily look at the orgmode source or something to figure this out, but for future reference what would I do to figure out what function something like this is bound to?
Edit: OK, so it's actually C-u followed by C-c C-q, and according to emacs this is what that combination is bound to:
(org-set-tags-command &optional arg just-align)
Call the set-tags command for the current entry.
So what exactly does it mean to give this command the argument 4?
Oh, just to give an explanation: I'm trying to start learning emacs-lisp and customization and one of the things I wanted to do was to have this command added to the before-save-hook so that when I save an org file, the tags get automatically aligned.
Final edit: I figured out why this command behaves as it does; given the prefix argument it changes its behavior. How can I set the prefix argument when calling the function in elisp?
It's not a general problem with combinations that are three keys long: For example, C-h c ESC ESC ESC (keyboard-escape-quit) or C-h c C-x r t (string-rectangle) both work fine.
When I try C-h c C-u C-c C-q in org-mode, the command interrupts after C-u and shows:
C-u runs the command universal-argument
in the minibuffer, which is correct. So, in fact, "C-u C-c C-q" is not a command, it's the command "C-c C-q" (org-table-wrap-region) started with an additional argument (4 -- see C-h k C-u for an explanation).