Emacs copy region/line and comment at the same time - emacs

I am trying to implement the following: duplicate the currently selected region or a line (if there is no selection) and comment out the original region with the help of comment-or-uncomment-region-or-line.
I figured I could use kill-region followed by yank but then my original selection is lost, so I can't comment. If on the other hand I comment first I will get both copies of my region commented out.
The other idea I have (which I think is better because I use evil-mode) is to use evil-yank and then evil-visual-restore to restore the selection so that I can comment it out. But I can't figure what arguments to pass to evil-yank to specify the selected region.
What am I missing here?

The main thing you are missing is function copy-region-as-kill.
(defun copy-and-comment-region (beg end &optional arg)
"Duplicate the region and comment-out the copied text.
See `comment-region' for behavior of a prefix arg."
(interactive "r\nP")
(copy-region-as-kill beg end)
(goto-char end)
(yank)
(comment-region beg end arg))

Related

Move current line to the header of current buffer in Emacs

I'm trying to find a way to automate/simplify the following use case:
I'm somewhere in the middle of a long file and I paste something.
Then I would like to send/move the current line (to the top header of the currently opened file). Most often this is some import/require function.
All of these ideally should happen without losing the relative position in a file (without setting markers manually).
How can I do this?
If it is important, I use Emacs primarily in evil-mode.
Here is the code:
(defun move-region-to-beginning-of-buffer (beg end)
"Move the region to the beginning of the buffer, then go back."
(interactive "r")
(let ((text (buffer-substring beg end)))
(save-excursion
(delete-region beg end)
(goto-char (point-min))
(insert text))))
Use it by selecting the text (actually, right after paste it is already marked) to be sent to the beginning of the buffer, then M-x move-region-to-beginning-of-buffer RET.
You can also bind this command to a key the usual way.

Delete from current position to the beginning of line in emacs?

Ctrlk would delete everything from the current position of the cursor to the end of line. Is there some equivalence to delete everything from the current position to the beginning of line?
For me Ctrl-0Ctrl-k does what you want. I think this is the default configuration, it's certainly not something I've modified.
If this doesn't work try Ctrl-u0Ctrl-k. Again, that seems to be Emacs' default behaviour on my installation (Emacs 24.x, Mac OS X).
If you prefer to have lesser keybinding (rather than having separate key to delete line, or having to invoke prefix-argument). You can use crux-smart-kill-line
which will "kill to the end of the line and kill whole line on the next
call". But if you prefer delete instead of kill, you can use the
code below.
For point-to-string operation (kill/delete) I recommend to use zop-to-char
(defun aza-delete-line ()
"Delete from current position to end of line without pushing to `kill-ring'."
(interactive)
(delete-region (point) (line-end-position)))
(defun aza-delete-whole-line ()
"Delete whole line without pushing to kill-ring."
(interactive)
(delete-region (line-beginning-position) (line-end-position)))
(defun crux-smart-delete-line ()
"Kill to the end of the line and kill whole line on the next call."
(interactive)
(let ((orig-point (point)))
(move-end-of-line 1)
(if (= orig-point (point))
(aza-delete-whole-line)
(goto-char orig-point)
(aza-delete-line))))
source
Emacs has steep learning curve. When a new user encounters this problem, she should record a macro of 2 keystrokes: Shift+Ctrl+a and Ctrl-w (cut), name it, save it, and set up a key binding so that the macro is available in the subsequent Emacs sessions.

Emacs comment/uncomment current line [duplicate]

This question already has answers here:
Eclipse-like Line Commenting in Emacs
(7 answers)
Closed 8 years ago.
I know there's already an Emacs question on this, and that it was closed, but I find it quite relevant and important.
Basically, I want to comment/uncomment the current line. I was expecting this to be fairly easy with a macro, but I found that it really isn't.
If the current line is commented, uncomment. If it is uncommented, comment it. And I would also to comment out the whole line, not just from cursor position.
I tried a macro like this:
C-a
'comment-dwim
But this only work to comment a line, not to uncomment it, if it's already commented.
I'm not sure of how easy it is, but if there's some way, I'd really like it.
Also, the reason I love this idea so much is that when I used Geany, I just used C-e and it was perfect.
Trey's function works perfectly, but it isn't very flexible.
Try this instead:
(defun comment-or-uncomment-region-or-line ()
"Comments or uncomments the region or the current line if there's no active region."
(interactive)
(let (beg end)
(if (region-active-p)
(setq beg (region-beginning) end (region-end))
(setq beg (line-beginning-position) end (line-end-position)))
(comment-or-uncomment-region beg end)))
It comments/uncomments the current line or the region if one is active.
If you prefer, you can modify the function to jump to the next line after (un)commenting the current line like this:
(defun comment-or-uncomment-region-or-line ()
"Comments or uncomments the region or the current line if there's no active region."
(interactive)
(let (beg end)
(if (region-active-p)
(setq beg (region-beginning) end (region-end))
(setq beg (line-beginning-position) end (line-end-position)))
(comment-or-uncomment-region beg end)
(next-line)))
Note that only thing that's changed is the added next-line command at the end of the function.
Try this function, and bind to your favorite key:
(defun toggle-comment-on-line ()
"comment or uncomment current line"
(interactive)
(comment-or-uncomment-region (line-beginning-position) (line-end-position)))
I took Trey's answer and refined it, so that it also works when a region is active, but then works on that region:
(defun comment-or-uncomment-line-or-region ()
"Comments or uncomments the current line or region."
(interactive)
(if (region-active-p)
(comment-or-uncomment-region (region-beginning) (region-end))
(comment-or-uncomment-region (line-beginning-position) (line-end-position))
)
)
(define-key c-mode-base-map (kbd "C-/") 'comment-or-uncomment-line-or-region)
I'm surprised the comment-region routine hasn't been mentioned. (Though I concede it may indicate I've missed something.) I've had the following line in my .emacs file for the better part of 20 years. It works well in most major programming modes I care about.
(global-set-key "\C-c\C-c" 'comment-region)
From the docs of 'comment-region'
Documentation: Comment or uncomment each line in the region. With just
C-u prefix arg, uncomment each line in region. Numeric prefix arg ARG
means use ARG comment characters. If ARG is negative, delete that many
comment characters instead. Comments are terminated on each line, even
for syntax in which newline does not end the comment. Blank lines do
not get comments.
I think you misunderstand how keyboard-macros work. What #Trey provided is a Emacs-Lisp command. You could have accomplished this for yourself without understanding Emacs-Lisp.
First figure out the sequence of keys that does what you want and then record that sequence as a macro.
You proposed this: C-a M-; (M-; is comment-dwim). Does it do what you had in mind? If not then it's not going to magically work when you play it back as a keyboard macro.
This answer applies here. It defines command comment-region-lines that comments or uncomments the current line, or the region if active.
It is similar to comment-or-uncomment-region, but it lets you decide whether to uncomment or comment. It lets you nest comments, instead of automatically uncommenting the region if it is already commented out.
With a numeric prefix arg it uses that many comment-start chars (e.g., ;, ;;, ;;;,... in Lisp). With a plain C-u prefix arg it uncomments. I bind it to C-x C-;.

Emacs command to insert and indent line above cursor

I frequently find myself typing on a line, when I realize I need(ed) a variable definition (or something similar) on the line above. What I would like is to
press C-return from anywhere on a line and have the cursor move to a newly inserted blank line above, with correct indentation (or at least the same as the original line).
be able to yank any text...
and C-u C-space to get back to the original position
I've managed to do #1, but my emacs-fu isn't strong enough to do the rest.
Here's my humble solution:
(defun my-insert-before-line ()
(interactive)
(save-excursion
(beginning-of-line)
; I've changed the order of (yank) and (indent-according-to-mode)
; in order to handle the case when yanked line comes with its own indent
(yank)(indent-according-to-mode)
; could be as well changed to simple (newline) it's metter of taste
; and of usage
(newline-and-indent)))
Hope it helps.
Here's what you can do if you are not a Zen master emacs dude.
Emacs has a record-macro thing, kmacro-start-macro and kmacro-end-macro.
After recording your macro, do name-last-kbd-macro. then visit .emacs, and do insert-kbd-macro.
You then have an fset statement that defines your macro. It may look funny, and it is not as maintainable as elisp, but if you stuff it into your .emacs, that macro (by that name) will be available to any of your editing sessions. And you can bind it to a key sequence as well.
Probably bad form to answer my own question, but Cheeso's answer motivated me to do some lisp programming for the second time in ten years (my original version was a named keyboard macro, but it stepped all over the kill/mark-rings). Here's what I came up with
(defun insert-and-indent-line-above ()
(interactive)
(push-mark)
(let*
((ipt (progn (back-to-indentation) (point)))
(bol (progn (move-beginning-of-line 1) (point)))
(indent (buffer-substring bol ipt)))
(newline)
(previous-line)
(insert indent)))
(global-set-key [ (control return) ] 'insert-and-indent-line-above)
there are probably many better ways of doing this, but two hours of lisp-hacking can hardly be called wasted time :-)

How do I get Emacs to fill sentences, but not paragraphs?

I've seen at least two recommendations on StackOverflow to insert newlines between sentences when editing LaTeX documents. The reason being that the practice facilitates source control, diffing, and collaborative editing.
I'm basically convinced, but I'm lazy, and I don't want to have to think about it.
So I'm searching for some emacs incantation to handle it for me. Could be a minor mode, could be a set of variables that need to be set.
I think what I don't want is
Soft wrapping of text (say using the longlines and (set long-lines-auto-wrap 't)). This is because I don't want to impose requirements on my collaborators' editors, and I sometimes use other unix tools to examine these files.
I think what I do want is
For fill-paragraph to fill between newlines that look like they mark the end of a sentence.
A solution that works with auto-fill-mode would be a bonus.
That is:
chat chat chat.
A new sentence
with goofed up wrapping that needs to be fixed.
Mumble mumble
Transformed to:
chat chat chat.
A new sentence with goofed up wrapping that needs to be fixed.
Mumble mumble
Your comments and suggestions are appreciated.
Edit: The suggestion by Jouni K. Seppänen pointed me at LaTeX-fill-break-at-separators, which suggests that emacs almost knows how to do this already. Anyway, I'm off to read some code, and will report back. Thanks again.
More general version of the same question: Editor showdown: Maintain newlines at the ends of sentences. Thanks, dreeves.
Here's what I use, which was mostly cribbed from Luca de Alfaro:
(defun fill-sentence ()
(interactive)
(save-excursion
(or (eq (point) (point-max)) (forward-char))
(forward-sentence -1)
(indent-relative t)
(let ((beg (point))
(ix (string-match "LaTeX" mode-name)))
(forward-sentence)
(if (and ix (equal "LaTeX" (substring mode-name ix)))
(LaTeX-fill-region-as-paragraph beg (point))
(fill-region-as-paragraph beg (point))))))
I bind this to M-j with
(global-set-key (kbd "M-j") 'fill-sentence)
The references to "LaTeX" are for AUCTeX support. If you don't use AUCTeX, the let can be simplified to
(let (beg (point))
(forward-sentence)
(fill-region-as-paragraph beg (point)))
I have been meaning to do this forever and I recently found this blog post which worked fairly well for me. So here is (a slightly modified version of) what I have been using for a few days.
(defun auto-fill-by-sentences ()
(if (looking-back (sentence-end))
;; Break at a sentence
(progn
(LaTeX-newline)
t)
;; Fall back to the default
(do-auto-fill)))
(add-hook 'LaTeX-mode-hook (lambda () (setq auto-fill-function 'auto-fill-by-sentences)))
;; Modified from http://pleasefindattached.blogspot.com/2011/12/emacsauctex-sentence-fill-greatly.html
(defadvice LaTeX-fill-region-as-paragraph (around LaTeX-sentence-filling)
"Start each sentence on a new line."
(let ((from (ad-get-arg 0))
(to-marker (set-marker (make-marker) (ad-get-arg 1)))
tmp-end)
(while (< from (marker-position to-marker))
(forward-sentence)
;; might have gone beyond to-marker---use whichever is smaller:
(ad-set-arg 1 (setq tmp-end (min (point) (marker-position to-marker))))
ad-do-it
(ad-set-arg 0 (setq from (point)))
(unless (or (looking-back "^\\s *")
(looking-at "\\s *$"))
(LaTeX-newline)))
(set-marker to-marker nil)))
(ad-activate 'LaTeX-fill-region-as-paragraph)
If you put a comment marker at the end of each sentence, Emacs knows not to move the next line inside the comment:
chat chat chat.%
A new sentence
with goofed up wrapping that needs to be fixed.%
Mumble mumble%
Then M-q fills each sentence separately, at least in AUCTeX 11.85. (If you test this in Emacs, there seems to be a bug where if this is the first paragraph in the buffer and you type M-q, you get an error message. Just put a newline before the text to work around it.)
If you don't want to type the comment characters, you could take LaTeX-fill-paragraph and modify it so that sentence-ending punctuation at end of line works similarly to comments.
(defun wrap-at-sentences ()
"Fills the current paragraph, but starts each sentence on a new line."
(interactive)
(save-excursion
;; Select the entire paragraph.
(mark-paragraph)
;; Move to the start of the paragraph.
(goto-char (region-beginning))
;; Record the location of the end of the paragraph.
(setq end-of-paragraph (region-end))
;; Wrap lines with 'hard' newlines (i.e., real line breaks).
(let ((use-hard-newlines 't))
;; Loop over each sentence in the paragraph.
(while (< (point) end-of-paragraph)
;; Determine the region spanned by the sentence.
(setq start-of-sentence (point))
(forward-sentence)
;; Wrap the sentence with hard newlines.
(fill-region start-of-sentence (point))
;; Delete the whitespace following the period, if any.
(while (char-equal (char-syntax (preceding-char)) ?\s)
(delete-char -1))
;; Insert a newline before the next sentence.
(insert "\n")))))
(global-set-key (kbd "M-q") 'wrap-at-sentences)
May not work in all circumstances, but:
(defun my-fill-sentence ()
"Fill sentence separated by punctuation or blank lines."
(interactive)
(let (start end)
(save-excursion
(re-search-backward "\\(^\\s-*$\\|[.?!]\\)" nil t)
(skip-syntax-forward "^w")
(setq start (point-at-bol)))
(save-excursion
(re-search-forward "\\(^\\s-*$\\|[.?!]\\)" nil t)
(setq end (point-at-eol)))
(save-restriction
(narrow-to-region start end)
(fill-paragraph nil))))
To make it work with auto-fill-mode, add (setq normal-auto-fill-function 'my-fill-sentence) to your LaTeX mode hook (I think).
I am assuming you know elisp.
There are a few approaches you can take:
Hook into auto-fill-mode. There are a lot of hard-coded
conditionals there, so it might not work for you. You can
potentially play with auto-fill-function and see if you have
the hook you need there.
Make a character (probably .) "electric" so that when you press
it, it inserts itself and then calls a function to determine how
to fill the line you're on.
Set an after-change-hook to call a function that determines how
to fill the sentence. This function will be called after every
change to the buffer, so do it efficiently. (This mechanism is
used by font-lock, so don't worry about it too much. It sounds
slow, but really isn't -- people type slowly.)
Once you have hooked in at the right place, you just have to implement
the filling logic. The source for sentence-at-point (from thingatpt) may be
instructive.
Anyway, I've never heard of anyone doing this... but it is definitely possible. Like most things in Emacs, it's just a Simple Matter Of Programming.
If the other answers are too automatic, here's a semiautomatic approach.
It's basically what you would do repeatedly if you were going to manually reformat, but condensed so you can hit a single key repeatedly instead.
;; - go to the end of the line,
;; - do ^d to suck the previous line onto this one,
;; - make sure there's only one space between the now-concatenated
;; lines, and then
;; - jump to the end and hit space so that (with auto-fill-mode)
;; the line nicely rewraps itself:
;; (turn on auto-fill-mode with M-x auto-fill-mode)
(defalias 'fill-sentence
(read-kbd-macro "C-e C-d SPC M-x just- one- space RET C-e SPC <backspace>"))
(define-key global-map [f4] 'fill-sentence) ; or whatever key you like
I like Chris Conway's macro a lot but it only works after you manually line-break each sentence. I'm a lazy guy so I want emacs to do it for me. This morning I finally sat down and looked into the problem. The solution I have now is to hack the built-in macro fill-region-as-paragraph.
After applying the following hack, a new option newline-after-sentence will be set to true. The standard M-q (fill-paragraph) will automatically fill and create line-breaks between sentences. Note that tests are only done with GNU Emacs 23.3.1 — use it at your own risk.
The full macro is long so I won't post it here. The idea is to add the following loops in fill-region-as-paragraph
...
;; Insert a line break after each sentence
(while (< (point) to)
(forward-sentence)
(if (< (point) to) (fill-newline)))
;; This is the actual filling loop.
(goto-char from)
(let (sentbeg sentend)
(while (< (point) to)
(setq sentbeg (point))
(end-of-line)
(setq sentend (point))
(fill-one-line sentbeg sentend justify) ;; original filling loop
(forward-line)))))
...
You can find the full macro in my git repository. Some details are also written in my blog. In case you don't want to read my poor English, you can simply use
$ curl http://fermi.mycloudnas.com/cgit.cgi/fill/plain/hack.el >> ~/.emacs
to append the hack to your ~/.emacs and give it a try. Comments and bug reports are all welcome.
An alternative approach would be to leave your .tex file as is, and use a tool like latexdiff
(described in this StackExchange post) instead of Unix diff. This produces a .tex file with Word-style track changes marks, and handles whitespace correctly so you don't have to worry about where your sentences end.
I wrote the following which loops over a region and inserts newlines. Instead of using forward-sentence which didn't work for me, I use re-search-forward "[.?!][]\"')}]*\\( \\)", which finds all sentences followed only by two spaces (the regexp is a modified sentence-end). The newline is made using newline-and-indent.
(defun fill-sentences-in-paragraph ()
"Put a newline at the end of each sentence in paragraph."
(interactive)
(save-excursion
(mark-paragraph)
(call-interactively 'fill-sentences-in-region)))
(defun fill-sentences-in-region (start end)
"Put a newline at the end of each sentence in region."
(interactive "*r")
(call-interactively 'unfill-region)
(save-excursion
(goto-char start)
(while (re-search-forward "[.?!][]\"')}]*\\( \\)" end t)
(newline-and-indent))))
To be able to fix improperly formatted text such as the example "chat chat chat...", fill-sentences-in-region first calls unfill-region which gets rid of sentence-breaking whitespace:
(defun unfill-region (beg end)
"Unfill the region, joining text paragraphs into a
single logical line. This is useful, e.g., for use
with 'visual-line-mode'."
(interactive "*r")
(let ((fill-column (point-max)))
(fill-region beg end)))
I use visual-line-mode and replace my default paragraph fill M-q to fill-sentences-in-paragraph with (global-set-key "\M-q" 'fill-sentences-in-paragraph).