How to kill a quoted string at point in emacs? - emacs

I would like to kill a quoted string in a source file
without having to mark the beginning of the string and kill-region,
but just by placing the point anywhere inside the quoted string and pressing a shortcut.
I tried to write a function in elisp for this, but I figured out that the file
would need to be parsed from the beginning up to point to determine whether the point is inside quoted string, and to find the bounds of the quoted string(also handle the \")...
But the file is already parsed by font-lock.
So now I can find out if I'm inside quoted string:
(defun inside-quoted-string? ()
(interactive)
(print (find 'font-lock-doc-face (text-properties-at (point)))))
But how do I get the bounds of the string?
font-lock knows it, since it nicely highlights it in blue, but how do I get it?
Edit:
Thanks for the answers. I came up with this code that does
exactly what I wanted - move code around without selecting region or even
moving to beginning of code.
(defun kill-at-point ()
"Kill the quoted string or the list that includes the point"
(interactive)
(let ((p (nth 8 (syntax-ppss))))
(if (eq (char-after p) ?\")
(progn
(goto-char p)
(kill-sexp))
(progn
(up-list)
(let ((beg (point)))
(backward-list)
(kill-region beg (point)))))))
(global-set-key (kbd "C-,") 'kill-at-point)
Any suggestions to improve it are welcome.

Rather than rely on font-lock, you can use the underlying parser's data. The start of the string around point (if any) is available as (nth 8 (syntax-ppss)). You can then use (forward-sexp 1) to jump over the string to find its end.

You can find the bounds of a property with previous-property-change and next-property-change. For example:
(defun kill-by-property (arg)
(interactive "d")
(kill-region
(previous-property-change arg nil (point-min))
(next-property-change arg nil (point-max))))

Building off of Stefan's suggestion of using syntax-ppss, the following should do the trick
(defun kill-string ()
(interactive)
(let ((string-start (nth 8 (syntax-ppss))))
(goto-char string-start)
(kill-sexp)))
It uses (nth 8 (syntax-ppss)) to find the beginning of the string, jumps there, then uses the built-in kill-sexp to kill the s-expression at point (in this case, the string we want gone). No need at all for any kind of region calculation on your part.

Related

Auto-escaping yanked strings in emacs

I apparently have a powerful itch this weekend to add a ton of functionality to my Emacs environment. I can do some basics on my own, and hunt down other stuff, but I haven't been able to find a solution to this (and am not good enough at Lisp to do it on my own).
I frequently work with strings of HTML, and sometimes if I move them from one block to another (or one language to another) strings are broken where they aren't escaped. So, I want a function that does something like this:
(defun smart-yank-in-string()
(if (stringp) ; Check if the point is in a string
; Check if the region created from the point to the end of the yank ends the string
; (and there is more yank left that isn't ";")
; Escape quotes for those locations recursively by prepending \
; Insert result into buffer # mark
))
Any clever ideas? I think it involves using kill-new to stash a variable and walk through it, but I'm not conversant enough in elisp to solve it.
Next yank should insert the escaped string:
(defun escape-doublequotes-at-car-of-kill-ring ()
"Escape doublequotes in car of kill-ring "
(interactive)
(with-temp-buffer
(insert (car kill-ring))
(goto-char (point-min))
(while (search-forward "\"" nil t 1)
(replace-match "\\\\\""))
(kill-new (buffer-substring-no-properties (point-min) (point-max)))))
Here is an alternative
(defun my-yank()
(interactive)
(if (nth 3 (syntax-ppss)) ;; Checks if inside a string
(insert-for-yank (replace-regexp-in-string "[\\\"]"
"\\\\\\&"
(current-kill 0)
t))
(call-interactively 'yank)))
The command when invoked checks if the point is in a string, if so it escapes the yanked text otherwise it yanks normally. One disadvantage is that you cannot use yank-pop after yanking inside a string.
Maybe you could do it as follow (guaranteed 100% non-functional code ahead):
(defun my-kill-quoted-string (start end)
"Like kill-region but takes of unquoting/requoting."
(interactive "r")
(let ((str (buffer-extract-substring start end)))
(if (nth 3 (syntax-ppss))
;; Unquote according to mode and context. E.g. we should unquote " and things like that in HTML.
(setq str (replace-regexp-in-string "\\\\\"" "\"" str)))
(put-text-property 0 (length str) 'yank-handler
(list (lambda (str)
(if (not (nth 3 (syntax-ppss)))
(insert str)
;; Requote according to mode and context.
(insert (replace-regexp-in-string "[\\\"]" "\\\\\\&" str))))))
(kill-new str)))

A Simple 'copy-form Command

I want a command that copies a form to the kill ring. In emacs-live, the closest thing I could find was this command / key-binding
(global-set-key (kbd "M-]") 'kill-ring-save)
However kill-ring-save has some wonky behaviour. Ii copies more than 1 form, past the cursor. Ultimately, I want a simple function along the lines of what's below (this doesn't quite work).
(defun copy-form ()
(kill-ring-save (line-beginning-position) (live-paredit-forward)))
(global-set-key (kbd "M-]") 'copy-form)
I've searched high and low ( SO question and Google search), but can't seem to find a simple, working command to copy a balanced expression. Has someone already done this?
Thanks
Tim
Function sexp-at-point gives you the sexp ("form") at the cursor. Just copy that to the kill-ring, using kill-ring-save. E.g.:
(defun copy-sexp-at-point ()
(interactive)
(let ((bnds (bounds-of-thing-at-point 'sexp)))
(kill-ring-save (car bnds) (cdr bnds))))
Alternatively, just use kill-new:
(defun copy-sexp-at-point ()
(interactive)
(kill-new (thing-at-point 'sexp)))
The reason your copy-form cannot be bound to a key is that it is a function, not a command - it is missing an interactive form.
However, in your case you don't even need to write a new function.
Try a combination of
mark-sexp is an interactive compiled Lisp function in `lisp.el'.
It is bound to C-M-#, C-M-SPC.
and
M-w runs the command kill-ring-save, which is an interactive compiled
Lisp function in `simple.el'.
It is bound to <C-insertchar>, M-w, <menu-bar> <edit> <copy>.
I'm not sure I understand the question, but when I need to do what I consider as "copy a balanced form", I do: M-C-SPC M-w. If I want to cut it instead, I do M-C-SPC C-w.
Here's what I generally use. Somehow it's more useful for me
to kill the balanced expression instead of copying. If I want a
copy instead, I first kill, then undo.
This function kills a string, if the point is inside string,
otherwise the balanced expression, i.e. (),[],{},<>
or whatever is defined by the syntax.
(defun kill-at-point ()
"Kill the quoted string or the list that includes the point"
(interactive)
(let ((p (nth 8 (syntax-ppss))))
(cond
;; string
((eq (char-after p) ?\")
(goto-char p)
(kill-sexp))
;; list
((ignore-errors (when (eq (char-after) ?\()
(forward-char))
(up-list)
t)
(let ((beg (point)))
(backward-list)
(kill-region beg (point)))))))
I've also tried to add a special case for when the point is
inside the comment, but I couldn't find a generic
way to determine bounds of comment at point. If anyone knows,
please tell me.
This other function can be relevant as well. It marks instead
of killing, like the previous one. The nice thing that it
extends the region each time it's called.
I bind the first one to C-, and the second to
C-M-,.
(defun mark-at-point ()
"Mark the quoted string or the list that includes the point"
(interactive)
(let ((p (nth 8 (syntax-ppss))))
(if (eq (char-after p) ?\")
(progn
(goto-char p)
(set-mark (point))
(forward-sexp))
(progn
(when (eq (char-after) 40)
(forward-char))
(condition-case nil
(progn
(up-list)
(set-mark (point))
(let ((beg (point)))
(backward-list)
(exchange-point-and-mark)))
(error
(when (looking-back "}")
(exchange-point-and-mark)
;; assumes functions are separated by one empty line
(re-search-backward "^[^A-Z-a-z]" nil t)
(forward-char))))))))

How to call query-replace-regexp inside a function?

I tend to use query-replace-regexp over an entire buffer rather than at the current position so I regularly use the sequence C-< (beginning-of-buffer), then C-r (query-replace-repexp).
I'd like to make another function bound to C-S-r (C-R) which does this for me. I thought that if I simply wrapped it all together such as:
(defun query-replace-regexp-whole-buffer ()
"query-replace-regexp from the beginning of the buffer."
(interactive)
(beginning-of-buffer)
(query-replace-regexp))
that this would be adequate, unfortunately though I'm getting some errors.
query-replace-regexp-whole-buffer: Wrong number of arguments: #[(regexp to-string &optional delimited start end) "Å Æ
Ç& " [regexp to-string delimited start end perform-replace t nil] 10 1940879 (let ((common (query-replace-read-args (concat "Query replace" (if current-prefix-arg " word" "") " regexp" (if (and transient-mark-mode mark-active) " in region" "")) t))) (list (nth 0 common) (nth 1 common) (nth 2 common) (if (and transient-mark-mode mark-active) (region-beginning)) (if (and transient-mark-mode mark-active) (region-end))))], 0
I can't really see what I'm doing wrong, hopefully someone can help.
When called from Lisp, query-replace-regexp expects to be passed regular expression and the intended replacement as arguments. If you want to emulate the questions asked when invoked interactively, you need to use call-interactively:
(defun query-replace-regexp-whole-buffer ()
"query-replace-regexp from the beginning of the buffer."
(interactive)
(goto-char (point-min))
(call-interactively 'query-replace-regexp))
Also note that one should never call beginning-of-buffer from Lisp code; it will do unnecessary work, such as pushing the mark and printing a message.
You need to read arguments yourself and pass them to query-replace-regexp... This could be done by extending your interactive, so function will look something like:
(defun query-replace-regexp-whole-buffer (regex to-string)
"query-replace-regexp from the beginning of the buffer."
(interactive "sRegex to search: \nsString to replace: ")
(save-excursion
(goto-char (point-min))
(query-replace-regexp regex to-string)))

'Semantic' movement across a line

Consider the following line of Lisp code:
(some-function 7 8 | 9) ;; some comment. note the extra indentation
The point is placed between '8' and '9'. If I perform (move-beginning-of-line), the point will be placed at the absolute beginning of the line, rather than at '('.
Same for move-end-of-line: I'd find it more desirable for it to place the point at ')' if I perform it once, and at the absolute end of the line if I perform it a second time. Some IDEs behave like that.
I tried to implement this but got stuck, my solution behaves particularly bad near the end of a buffer, and on the minibuffer as well. Is there a library that provides this functionality?
I don't know of any library, but it can be done in a few lines of Elisp.
For the beginning of line part, the bundled functions beginning-of-line-text and back-to-indentation (M-m) move to the beginning of the “interesting” part of the line. back-to-indentation ignores only whitespace whereas beginning-of-line-text skips over the fill prefix (in a programming language, this is typically the comment marker, if in a comment). See Smart home in Emacs for how to flip between the beginning of the actual and logical line.
For the end of line part, the following function implements what you're describing. The function end-of-line-code moves to the end of the line, except for trailing whitespace and an optional trailing comment. The function end-of-line-or-code does this, except that if the point was already at the target position, or if the line only contains whitespace and a comment, the point moves to the end of the actual line.
(defun end-of-line-code ()
(interactive "^")
(save-match-data
(let* ((bolpos (progn (beginning-of-line) (point)))
(eolpos (progn (end-of-line) (point))))
(if (comment-search-backward bolpos t)
(search-backward-regexp comment-start-skip bolpos 'noerror))
(skip-syntax-backward " " bolpos))))
(defun end-of-line-or-code ()
(interactive "^")
(let ((here (point)))
(end-of-line-code)
(if (or (= here (point))
(bolp))
(end-of-line))))
Some suggestions that almost do what you ask:
In lisp code, you can sort-of do what you want, with the sexp movement commands. To get to the beginning of the expression from somewhere in the middle, use backward-up-list, which is bound to M-C-u. In your example, that would bring you to the open parenthesis. To move backwards over individual elements in the list, use backward-sexp, bound to M-C-b; forward-sexp moves the other way, and is bound to M-C-f. From the beginning of an sexp, you can skip to the next with M-C-n; reverse with M-C-p.
None of these commands are actually looking at the physical line you are on, so they'll go back or forward over multiple lines.
Other options include Ace Jump mode, which is a very slick way to quickly navigate to the beginning of any word visible on the screen. That might eliminate your need to use line-specific commands. For quick movement within a line, I usually use M-f and M-b to jump over words. Holding the M key down while tapping on b or f is quick enough that I end up using that by default most of the time.
Edit:
Forgot one other nice command - back-to-indentation, bound to M-m. This will back you up to the first non-whitespace character in a line. You could advice this to behave normally on the first call, and then to back up to the beginning of the line on the second call:
(defadvice back-to-indentation (around back-to-back)
(if (eq last-command this-command)
(beginning-of-line)
ad-do-it))
(ad-activate 'back-to-indentation)
I just wrote these two functions that have the behavior you are looking for.
(defun move-beginning-indent ()
(interactive)
(if (eq last-command this-command)
(beginning-of-line)
(back-to-indentation))
)
(defun move-end-indent ()
(interactive)
(if (eq last-command this-command)
(end-of-line)
(end-of-line)
(search-backward-regexp "\\s)" nil t) ; searches backwards for a
(forward-char 1)) ; closed delimiter such as ) or ]
)
(global-set-key [f7] 'move-beginning-indent)
(global-set-key [f8] 'move-end-indent)
Just try them out, they should behave exactly the way you'd want them to.
I use this:
(defun beginning-of-line-or-text (arg)
"Move to BOL, or if already there, to the first non-whitespace character."
(interactive "p")
(if (bolp)
(beginning-of-line-text arg)
(move-beginning-of-line arg)))
(put 'beginning-of-line-or-text 'CUA 'move)
;; <home> is still bound to move-beginning-of-line
(global-set-key (kbd "C-a") 'beginning-of-line-or-text)
(defun end-of-code-or-line ()
"Move to EOL. If already there, to EOL sans comments.
That is, the end of the code, ignoring any trailing comment
or whitespace. Note this does not handle 2 character
comment starters like // or /*. Such will not be skipped."
(interactive)
(if (not (eolp))
(end-of-line)
(skip-chars-backward " \t")
(let ((pt (point))
(lbp (line-beginning-position))
(comment-start-re (concat (if comment-start
(regexp-quote
(replace-regexp-in-string
"[[:space:]]*" "" comment-start))
"[^[:space:]][[:space:]]*$")
"\\|\\s<"))
(comment-stop-re "\\s>")
(lim))
(when (re-search-backward comment-start-re lbp t)
(setq lim (point))
(if (re-search-forward comment-stop-re (1- pt) t)
(goto-char pt)
(goto-char lim) ; test here ->
(while (looking-back comment-start-re (1- (point)))
(backward-char))
(skip-chars-backward " \t"))))))
(put 'end-of-code-or-line 'CUA 'move)
;; <end> is still bound to end-of-visual-line
(global-set-key (kbd "C-e") 'end-of-code-or-line)

Change mark-paragraph behaviour

How to change default emacs mark-paragraph function behaviour to not select first empty line?
my emacs http://dl.dropbox.com/u/1019877/e2.PNG
I've made Bohzidars upgraded version and it works for first line too.
(global-set-key (kbd "M-h") (lambda ()
(interactive)
(mark-paragraph)
(if (> (line-number-at-pos) 1)
(next-line))
(beginning-of-line)))
thanks guys for the tips.
The currently accepted answer has two disadvantages: 1) doesn't accept arguments and 2) doesn't allow to mark more paragraphs by repeated calls (especially this is very useful). Here is my solution - it is the original mark-paragraph with a next-line command at the end. The condition assures it works also on the first of the file.
Possibly a more economic solution is to use advices, but I don't know how to use them yet :).
(defun rs-mark-paragraph (&optional arg allow-extend)
"The original default mark-paragraph, but doesn't mark the first
empty line. Put point at beginning of this paragraph, mark at
end. The paragraph marked is the one that contains point or
follows point.
With argument ARG, puts mark at end of a following paragraph, so that
the number of paragraphs marked equals ARG.
If ARG is negative, point is put at end of this paragraph, mark is put
at beginning of this or a previous paragraph.
Interactively, if this command is repeated
or (in Transient Mark mode) if the mark is active,
it marks the next ARG paragraphs after the ones already marked."
(interactive "p\np")
(unless arg (setq arg 1))
(when (zerop arg)
(error "Cannot mark zero paragraphs"))
(cond ((and allow-extend
(or (and (eq last-command this-command) (mark t))
(and transient-mark-mode mark-active)))
(set-mark
(save-excursion
(goto-char (mark))
(forward-paragraph arg)
(point))))
(t
(forward-paragraph arg)
(push-mark nil t t)
(backward-paragraph arg)
(if (/= (line-number-at-pos) 1)
(next-line)))))
You cannot change the behaviour of mark-paragraph, but you can easily bind another command to the C-M-h keystroke (to resemble the original M-h):
(global-set-key (kbd "C-M-h") (lambda ()
(interactive)
(mark-paragraph)
(next-line)
(beginning-of-line)))
Something like this should do the trick.
I'm not sure I see a convenient way to do this. mark-paragraph calls forward-paragraph and backward-paragraph to do the bulk of the work, and in the documentation for backward-paragraph, we have "if the first real line of a paragraph is preceded by a blank line, the paragraph starts at that blank line."
The most relevant variables to look at appear to be paragraph-start and paragraph-separate, two regular expressions used inside paragraphs.el to figure out this sort of thing. I'd be leary of changing them though, as they are going to have quite a lot of other effects.
Another option is to write your own function that does something like the following:
(defun dg-mark-paragraph ()
(interactive)
(mark-paragraph)
(goto-char (region-beginning))
(when (= (string-match paragraph-separate (thing-at-point 'line)) 0)
(forward-line)))