Bracket selected text in Emacs - emacs

I want to use Emacs for simple text annotation. Is there a command which surrounds a selected region of text with brackets or other characters?

The most structured and flexible way to do this is with autopair. I
would say it has become the canonical solution for inserting paired delimiters
and wrapping content in paired delimiters.
Joao (autopair's author) has also written yasnippet, which is a very
popular templating library in Emacs. yasnippet can be used to wrap
region in arbitrary text.
Both libraries model their behaviour on Textmate.

I don't know if there is a standard emacs command to do this, but this one should do the trick:
(defun surround-brackets ()
"Surround current region with brackets"
(interactive)
(when (use-region-p)
(save-excursion
(let ((beg (region-beginning))
(end (region-end)))
(goto-char end)
(insert "]")
(goto-char beg)
(insert "[")))))
EDIT As noted in the comments, this question proposes the following solution, which is much simpler but requires you to use a key binding ending with [
(global-set-key (kbd "M-[") 'insert-pair)

Related

Emacs: Assign a function to a keybinding, and with repeated presses, undo the last press and redo at a wider setting

Here's the bigger picture of what I'm trying to do:
With a keypress, it will insert an opening and closing parenthesis right after/before the innermost closing/opening delimiter (bracket, brace, parenthesis, whatever).
But if it is pressed immediately after, it will undo the last insertions, seek out the next closing delimiter, and put it after that, and so on.
I have a working version of the first part, but am looking for "best practices" for the second part (where it undoes and moves outwards)
As a motivator and concrete example, this is a typical scenario when coding in Python. I work with list comprehensions a lot, and often I construct the list, and then decide I want to sum all elements, etc. So I would first type:
[x*x for x in some_lst if is_prime(x)]
and then I'll want to encapsulate this list with a "sum" command:
sum([x*x for x in some_lst if is_prime(x)])
I don't want to have to keep moving the cursor to both the beginning and the end just to insert the parentheses. I'd rather have the point in the list, press a keystroke, have it figure out the delimiters, and place the mark just before the opening inserted parenthesis so that I can type "sum". My function below seems to work (piggybacking on the "expand-region" package):
(defun add-paren ()
(interactive)
(er/mark-outside-pairs)
(exchange-point-and-mark)
(insert-string ")")
(exchange-point-and-mark)
(insert-string "(")
(left-char 1)
)
What's the best practice for the 2nd step?
(Any suggestions/improvements to the above would also be appreciated. This is my first "real" function in Elisp.)
Thanks.
Update: Thanks everyone for the tips. I'll probably use some of them in my final solution. My original question still stands: Is there a standard pattern of "undoing and redoing at a larger scale", or will each problem have its own custom solution? Suppose I use smartparens as suggested to do it all in one keystroke, but I want it to occur on the 3rd level out. What I want is to press the keystroke 3 times and have it place the parentheses there.
So after the first keystroke, it places the parentheses at the innermost level. Pressing it again should remove the inserted parentheses, and place them in the next level up, and so on...
(BTW, not trying to reinvent the wheel. I suspect some of the packages listed may have exactly what I need - I just want practice coding in Elisp).
Update 2:
I guess there is no best practice for this? Anyway, I solved the problem using both expand-region and smartparens:
(defun add-paren ()
(interactive)
(if (eq last-command 'add-paren)
;; (message "AAAA")
(delete-paren)
)
(setq currpoint (point))
(er/mark-outside-pairs)
(if (eq currpoint (point))
(er/mark-outside-pairs)
)
(sp-wrap-with-pair "(")
(left-char 1)
)
(global-set-key (kbd "<f5>") 'add-paren)
(defun delete-paren ()
(interactive)
(setq currloc (point))
(sp-unwrap-sexp)
(goto-char currloc)
(left-char 1)
)
You're already using expand-region. Why not combine that with one of the many "surround region with..." modes?
I personally like smartparens (available via Marmalade or MELPA), but there are many other similar tools.
Use er/expand-region until you've got an appropriate selection, then
( to wrap in parentheses.
When programming, there are several hundred slightly different edit-tasks of this kind. Therefor created a toolkit for it.
In example given, the form might be described as delimited, more precisely bracketed.
ar-bracketed-atpt would mark it.
It's set here like this:
(global-set-key [(super \])] 'ar-bracketed-atpt)
Then comes in another class of commands which do several things on active region. In this case:
M-x ar-parentize-or-copy-atpt RET
It is bound to C-c )
A tarball for all this stuff is available here:
https://launchpad.net/s-x-emacs-werkstatt/
FWIW, I'd do it as follows:
go before the open bracket.
type sum C-M-SPC (
The C-M-SPC selects the parenthesized (well, "bracketized") expression, and the subsequent ( wraps it in parens (because of electric-pair-mode).
I guess there is no best practice for this? Anyway, I solved the problem using both expand-region and smartparens:
(defun add-paren ()
(interactive)
(if (eq last-command 'add-paren)
;; (message "AAAA")
(delete-paren)
)
(setq currpoint (point))
(er/mark-outside-pairs)
(if (eq currpoint (point))
(er/mark-outside-pairs)
)
(sp-wrap-with-pair "(")
(left-char 1)
)
(global-set-key (kbd "<f5>") 'add-paren)
(defun delete-paren ()
(interactive)
(setq currloc (point))
(sp-unwrap-sexp)
(goto-char currloc)
(left-char 1)
)

Emacs: Insert word at point into replace string query

Is there an analogue to inserting the word after point into the isearch query by hitting C-w after C-s but for the replace string (and replace regexp) queries?
I also enjoy Sacha Chua's modification of C-x inserting whole word around point into isearch:
http://sachachua.com/blog/2008/07/emacs-keyboard-shortcuts-for-navigating-code/
This too would be really useful in some cases if it could be used in replace string.
I'd be very thankful for any tips!
Thank you!
This will do it, although it isn't as fancy as C-w in isearch because you can't keep hitting that key to extend the selection:
(defun my-minibuffer-insert-word-at-point ()
"Get word at point in original buffer and insert it to minibuffer."
(interactive)
(let (word beg)
(with-current-buffer (window-buffer (minibuffer-selected-window))
(save-excursion
(skip-syntax-backward "w_")
(setq beg (point))
(skip-syntax-forward "w_")
(setq word (buffer-substring-no-properties beg (point)))))
(when word
(insert word))))
(defun my-minibuffer-setup-hook ()
(local-set-key (kbd "C-w") 'my-minibuffer-insert-word-at-point))
(add-hook 'minibuffer-setup-hook 'my-minibuffer-setup-hook)
EDIT:
Note that this is in the standard minibuffer, so you can use it use it anywhere you have a minibuffer prompt, for example in grep, occur, etc.
Two answers:
Replace+ automatically picks up text at point as the default value when you invoke replace commands.
More generally, Icicles does something similar to what scottfrazer's code (above) does, but it is more general. At any time, in any minibuffer, you can hit M-. (by default) to pick up text ("things") at point and insert it in the minibuffer. You can repeat this, to either (a) pick up successive things (e.g. words) of the same kind, accumulating them like C-w does for Isearch, or (b) pick up alternative, different things at point. More explanation here.
I think this exists in Emacs already - you just start replace with M-S-% and then press M-n (while the minibuffer is empty), this fills in the word under cursor, there are more useful things you can do with this, check http://endlessparentheses.com/predicting-the-future-with-the-m-n-key.html?source=rss#disqus_thread.

By Emacs, how to join two lines into one?

I am new to Emacs. I have googled this but no good answer there. One of them is
Ctrl-n Ctrl-a Backspace
This works but is stupid. Is there a quick and simple way to join a block of lines into a single line?
Actually, I can use Esc-q to auto-fill a paragraph now, but how could I get it to revert without UNDO?
Place point anywhere on the last line of the group of lines that need joining and call
M-^
repeatedly until all the lines are merged.
Note: It leaves one space between all of the now joined lines.
M-x join-line will join two lines. Just bind it to a convenient keystroke.
Multiple Cursors combined with M-^ will collapse all selected lines into one with all extraneous white-space removed.
For example to select an entire buffer, invoke multiple cursors mode, collapse into one line, and then disable multiple cursors mode:
C-x h
M-x mc/edit-lines
M-^
C-g
The Emacs conventional name for "join" is "fill". Yes, you can join
two lines with M-^ -- and that's handy -- but more generally you'll
want to join n lines. For this, see the fill* commands, such as
fill-region, fill-paragraph, etc.
See this for more info
on selecting things which can then be filled.
Also, you can join multiple lines with M-^ by selecting those lines first. (Note that the universal argument does not work with this.)
Just replace newlines with nothing.
I like the way Sublime text Join line with Command J so I do it this way:
(defun join-lines (arg)
(interactive "p")
(end-of-line)
(delete-char 1)
(delete-horizontal-space)
(insert " "))
You could define a new command for this, temporarily adjusting the fill width before using the the Esc-q command:
;; -- define a new command to join multiple lines together --
(defun join-lines () (interactive)
(setq fill-column 100000)
(fill-paragraph nil)
(setq fill-column 78)
)
Obviously this only works, if your paragraph has less than 100000 characters.
I use the following function and bind it to 'M-J'.
(defun concat-lines ()
(interactive)
(next-line)
(join-line)
(delete-horizontal-space))
If you prefer to keep your cursor position, you can use save-excursion.
The most simplest way ever:
Select paragraph/lines by M-h or C-SPC
Press M-q
Witness the Emagics (Emacs Magic)!!
Because join-line will left one space between two lines, also it only support join two lines. In case of you want to join plenty of lines without one space left, you can use "search-replace" mode to solve, as follows:
C-%
Query: input C-q C-j Enter
Replace: Enter
Run the replacement. Enter
Done.
Two ways come to mind:
Once you think of it, the most obvious (or at least easiest to remember) way is to use M-q format-paragraph with a long line length C-x-f 1000.
There is also a built-in tool M-^ join-line. More usefully, if you select a region then it will combine them all into one line.
"how could I get it to revert without UNDO?":
(defun toggle-fill-paragraph ()
;; Based on http://xahlee.org/emacs/modernization_fill-paragraph.html
"Fill or unfill the current paragraph, depending upon the current line length.
When there is a text selection, act on the region.
See `fill-paragraph' and `fill-region'."
(interactive)
;; We set a property 'currently-filled-p on this command's symbol
;; (i.e. on 'toggle-fill-paragraph), thus avoiding the need to
;; create a variable for remembering the current fill state.
(save-excursion
(let* ((deactivate-mark nil)
(line-length (- (line-end-position) (line-beginning-position)))
(currently-filled (if (eq last-command this-command)
(get this-command 'currently-filled-p)
(< line-length fill-column)))
(fill-column (if currently-filled
most-positive-fixnum
fill-column)))
(if (region-active-p)
(fill-region (region-beginning) (region-end))
(fill-paragraph))
(put this-command 'currently-filled-p (not currently-filled)))))
(global-set-key (kbd "M-q") 'toggle-fill-paragraph)
From EmacsWiki: Unfill Paragraph
;;; Stefan Monnier <foo at acm.org>. It is the opposite of fill-paragraph
(defun unfill-paragraph (&optional region)
"Takes a multi-line paragraph and makes it into a single line of text."
(interactive (progn (barf-if-buffer-read-only) '(t)))
(let ((fill-column (point-max))
;; This would override `fill-column' if it's an integer.
(emacs-lisp-docstring-fill-column t))
(fill-paragraph nil region)))
A basic join of 2 lines:
(delete-indentation)
I like to line below to be joined to the current without moving the cursor:
("C-j" .
(lambda (iPoint)
"Join next line onto current line"
(interactive "d")
(next-line)
(delete-indentation)
(goto-char iPoint)))
This one behaves like in vscode. So it add space only if join line consisted something else than whitespace. And I bind it to alt+shift+j.
Shorter version based on crux-top-join-line:
(global-set-key (kbd "M-J") (lambda () (interactive) (delete-indentation 1)))
Longer version based on https://stackoverflow.com/a/33005183/588759.
;; https://stackoverflow.com/questions/1072662/by-emacs-how-to-join-two-lines-into-one/68685485#68685485
(defun join-lines ()
(interactive)
(next-line)
(join-line)
(delete-horizontal-space)
(unless (looking-at-p "\n") (insert " ")))
(global-set-key (kbd "M-J") 'join-lines)

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).