all
Now I'm editing c sources with emacs under c-mode. How ever auto-fill-mode doesn't seem to work at all. Here how I enabled and tried to use it.
M-x auto-fill-mode (enable auto-fill-mode)
Typed in a line longer than auto-fill size(which 80 characters for now) --> didn't break the line
Tried to auto-filled by issuing M-q
However above attempt didn't work out at all.
Could anybody point out that what have I done wrong?
Thanks for your help in advance.
When you use auto-fill-mode in c-mode, the default behavior is to wrap text only when writing text, as in a comment. You can override this by customizing the value of c-ignore-auto-fill. Note that emacs will wrap and indent your code as text, which is probably not what you want.
A better solution is probably to bind space to a function like this:
(defun insert-space-or-newline-and-indent ()
(interactive)
(if (>= (current-column) fill-column)
(newline-and-indent)
(insert-char ? )))
Related
I've just started using emacs, and there's one feature I'd really like, and searching around a bit was fruitless. I hope someone else has done this because I don't want to learn elisp just yet.
void foo()<cursor>
I would like typing an "{" to cause this to happen
void foo(){
<cursor>
}
I would like this to only happen in cc-mode, and only at the end of a line when not in a string/comment/etc
The first thing that came to mind was rebinding "{" to do this always(I could figure out how to do this myself), but it would be hard to make it only happen at the right time.
any hints would be appreciated.
on latest emacs you can use :
electric-pair-mode is an interactive compiled Lisp function.
(electric-pair-mode &optional ARG)
Automatically pair-up parens when inserting an open paren.
this is integrated in Emacs 24.1 (actually CVS)
This will do it:
(defun my-c-mode-insert-lcurly ()
(interactive)
(insert "{")
(let ((pps (syntax-ppss)))
(when (and (eolp) (not (or (nth 3 pps) (nth 4 pps)))) ;; EOL and not in string or comment
(c-indent-line)
(insert "\n\n}")
(c-indent-line)
(forward-line -1)
(c-indent-line))))
(define-key c-mode-base-map "{" 'my-c-mode-insert-lcurly)
turn on electric-pair-mode in emacs 24 or newer version.
(electric-pair-mode 1)
I heartily recommend you to try out the excellent autopair minor mode - it does a lot more than simply inserting braces and makes Emacs a lot more IDE like in that area. I guess combining it with the electric braces setting in cc-mode will give you more or less the behavior you seek.
Try yasnippet (or on the Emacs Wiki page yasnippet). There are many packages for Emacs which support doing this kind of thing, but yasnippet seems to have momentum currently and is very extensible. Check out the videos.
You will need to delve into emacs-lisp to do this exactly as you wish, since YASnippet will do something nice for you but not exactly what you're asking for.
I think the simplest way to do this would be to bind a function to the RET key, in the cc-mode key-map.
The function should check to that the previous character is an { and if so, perform the required RET, RET, TAB, }, Up, TAB to get the cursor where you want and the closing } inserted.
You can make the feature more robust by having it check for a balanced closing } but this would be more complicated, and I'd recommend seeing how it feels without this additional polishing feature.
If you like I can write the function and the key-map binding for you, but since you asked for an idea of how it's done, I'll leave it up to you to ask for more assistance if you need it.
Alternatively, I find that autopair.el does this nicely enough for me, and I do the newlines myself ;)
You might want to keep the option of an empty function body, in which case you would want the closing brace to stay on the same line. If that is the case, then you can try this alternative solution:
Rely on the packages mentioned in the previous replies to automatically add the closing brace.
When you want to add statements to the function body, you press the Return key (while the automatically added closing brace is still under the cursor). The 'Return' key is bound as follows:
;; automatic first line in function
(defun my-c-mode-insert-funline ()
(interactive)
(newline-and-indent)
(when (looking-at "}")
(newline-and-indent)
(forward-line -1)
(c-indent-line)))
(global-set-key (kbd "RET") 'my-c-mode-insert-funline)
I have an issue using Emacs 24.1.1 on Mac OS X. I'm editing Jade and CoffeeScript files, so I've turned on whitespace-mode for those file types.
What I'm seeing is that lines longer than 70 characters are highlighted with the whitespace-line font face, regardless of the setting of whitespace-line-column.
In this shot, it is clear that I've customized whitespace-line-column to track fill-column, and I've set fill-column to 120, but much shorter lines are being highlighted.
I've glanced over the code for the Jade mode and don't see anything that would explain the behavior, but I have only a passing understanding of Emacs Lisp.
Thanks in advance for any pointers!
You have to set whitespace-line-column before you activate whitespace-mode. That is, if you want to change its value it does not take effect unless you turn whitespace-mode off and on again. Ironically, that variable is not available for M-x customize until you have activated the mode once :-(
However, you can customize the global value of this variable by putting the following line in your .emacs file:
(setq whitespace-line-column 120)
Since your .emacs is evaluated when you start Emacs, the setting will take effect before you invoke whitespace-mode for the first time and should thus do what you want. If you don't want to set the value globally, but only for Jade files, put the following in your .emacs file instead:
(set (make-local-variable 'whitespace-line-column) 80)
(add-hook 'after-change-major-mode-hook
'(lambda () (when (eq major-mode 'jade-mode)
(setq whitespace-line-column 120))))
If you never want long lines to be highlighted specially at all, there is a third option you might want to consider. You could customize the variable whitespace-style (by typing M-x customize-variable ENTER whitespace-style ENTER) and in the value list remove the entries:
lines
lines-tail
(if any). This should turn off highlighting of long lines globally independent of the value of whitespace-line-column (again, only after you de- and re-activate whitespace mode).
I've just started using emacs, and there's one feature I'd really like, and searching around a bit was fruitless. I hope someone else has done this because I don't want to learn elisp just yet.
void foo()<cursor>
I would like typing an "{" to cause this to happen
void foo(){
<cursor>
}
I would like this to only happen in cc-mode, and only at the end of a line when not in a string/comment/etc
The first thing that came to mind was rebinding "{" to do this always(I could figure out how to do this myself), but it would be hard to make it only happen at the right time.
any hints would be appreciated.
on latest emacs you can use :
electric-pair-mode is an interactive compiled Lisp function.
(electric-pair-mode &optional ARG)
Automatically pair-up parens when inserting an open paren.
this is integrated in Emacs 24.1 (actually CVS)
This will do it:
(defun my-c-mode-insert-lcurly ()
(interactive)
(insert "{")
(let ((pps (syntax-ppss)))
(when (and (eolp) (not (or (nth 3 pps) (nth 4 pps)))) ;; EOL and not in string or comment
(c-indent-line)
(insert "\n\n}")
(c-indent-line)
(forward-line -1)
(c-indent-line))))
(define-key c-mode-base-map "{" 'my-c-mode-insert-lcurly)
turn on electric-pair-mode in emacs 24 or newer version.
(electric-pair-mode 1)
I heartily recommend you to try out the excellent autopair minor mode - it does a lot more than simply inserting braces and makes Emacs a lot more IDE like in that area. I guess combining it with the electric braces setting in cc-mode will give you more or less the behavior you seek.
Try yasnippet (or on the Emacs Wiki page yasnippet). There are many packages for Emacs which support doing this kind of thing, but yasnippet seems to have momentum currently and is very extensible. Check out the videos.
You will need to delve into emacs-lisp to do this exactly as you wish, since YASnippet will do something nice for you but not exactly what you're asking for.
I think the simplest way to do this would be to bind a function to the RET key, in the cc-mode key-map.
The function should check to that the previous character is an { and if so, perform the required RET, RET, TAB, }, Up, TAB to get the cursor where you want and the closing } inserted.
You can make the feature more robust by having it check for a balanced closing } but this would be more complicated, and I'd recommend seeing how it feels without this additional polishing feature.
If you like I can write the function and the key-map binding for you, but since you asked for an idea of how it's done, I'll leave it up to you to ask for more assistance if you need it.
Alternatively, I find that autopair.el does this nicely enough for me, and I do the newlines myself ;)
You might want to keep the option of an empty function body, in which case you would want the closing brace to stay on the same line. If that is the case, then you can try this alternative solution:
Rely on the packages mentioned in the previous replies to automatically add the closing brace.
When you want to add statements to the function body, you press the Return key (while the automatically added closing brace is still under the cursor). The 'Return' key is bound as follows:
;; automatic first line in function
(defun my-c-mode-insert-funline ()
(interactive)
(newline-and-indent)
(when (looking-at "}")
(newline-and-indent)
(forward-line -1)
(c-indent-line)))
(global-set-key (kbd "RET") 'my-c-mode-insert-funline)
Please for the love of god how can I make Emacs stop auto-filling? I use visual-line-mode, I do not want auto fill. I can turn it off with M-x auto-fill-mode RET but in Noweb mode it gets turned back on when I move into a code chunk and back out again. Please, I just want to globally turn of auto fill mode, it's driving me crazy.
I've tried
(auto-fill-mode 0)
and a bunch of crazy things like
(add-hook 'Rnw-mode-hook '(lambda () (auto-fill-mode 0)))
(add-hook 'latex-mode-hook '(lambda () (auto-fill-mode 0)))
But nothing seems to work. Please help me.
Instead of adding further hooks to your system, you should check if you could remove some to disable auto-fill.
If you see noweb-mode's source code, around line 211 you find this chunk:
(add-hook 'noweb-select-doc-mode-hook 'noweb-auto-fill-doc-mode)
(add-hook 'noweb-select-code-mode-hook 'noweb-auto-fill-code-mode)
To disable auto filling, put the following one or two lines in your dotemacs (depending on whether you want to disable auto-fill in both code and documentation).
(remove-hook 'noweb-select-doc-mode-hook 'noweb-auto-fill-doc-mode)
(remove-hook 'noweb-select-code-mode-hook 'noweb-auto-fill-code-mode)
OK, I worked out a hack that does the trick:
(setq auto-fill-mode -1)
(setq-default fill-column 99999)
(setq fill-column 99999)
If I can't turn off auto-fill mode, at least I can make it harmless by setting it to fill only in column 99999. I'll be annoyed if I type a paragraph with more than 99999 characters, but if that happens I'll have bigger things to worry about...
If you look at simple.el, at the very top text-mode-hook is defined, which is ultimately responsible for turning on this abomination (or at least, it was for me).
To get to simple.el and look for yourself: (C-h f, auto-fill-mode, click / follow simple.el link)
To disable, M-x customize-variable text-mode-hook
Screen shot
Uncheck turn-on-auto-fill. Be sure to click "Save for future sessions" at the top.
I am having a problem with doxygen style multi-line comments with emacs indent feature in c-mode. According to doxygen manual (http://www.doxygen.nl/manual/docblocks.html) the form below is accepted.
/********************************************//**
* ... text
***********************************************/
I am trying to use this format in emacs but when I tab in on the line '* ... text' the * ends up below the /** at the end of the first line like so:
/********************************************//**
* ... text
***********************************************/
Any suggestions on how to fix this? Still learning all the in-and-outs of emacs.
The reason it is indenting as such is that (by default) multi-line comments are lined up with the start of the comment on the previous line. In this case, the start of the containing comment is in column 47.
Now, how to fix it. Here's how I figured out how to fix it, the solution is at the end.
First, there's the cc-mode manual, specifically the section on customizing indentation. A useful key is C-c C-s which tells you which syntax is being used for indentation. In this case it is ((c 61)) - the c is the important part for now.
To customize it interactively, you can type C-c C-o (when the point is on the line whose indentation you want to fix). You'll be prompted for which syntax entry you want to customize (defaults to c in this case b/c that's the current syntax), then you'll be prompted for what you want to change the syntax entry to (default is c-lineup-C-comments).
Now we can look at that function to see how we might customize it to meet your needs. M-x find-function c-lineup-C-comments.
That's where it gets more difficult. You can customize the way cc-mode handles comment indentation, but what it looks like you want it to do (in this case) is to recognize that the c-comment you're in is immediately preceded by another c-comment, and that comment is the one you want to align indentation to.
How do you do that? The easiest way I can think of is to advise 'c-lineup-C-comments to recognize this special case and change the value of its first argument to be what you want. My limited testing shows this works for your example:
(defadvice c-lineup-C-comments (before c-lineup-C-comments-handle-doxygen activate)
(let ((langelm (ad-get-arg 0)))
(save-excursion
(save-match-data
(goto-char (1+ (c-langelem-pos langelem)))
(if (progn
(beginning-of-line)
;; only when the langelm is of form (c . something)
;; and we're at a doxygen comment line
(and (eq 'c (car langelm))
(looking-at "^\\(\\s-*\\)/\\*+//\\*\\*$")))
;; set the goal position to what we want
(ad-set-arg 0 (cons 'c (match-end 1))))))))
The end result of this advice should be that the argument passed into c-lineup-C-comments should be transformed from (c . 61) to (c . 17) (or something like that), essentially fooling the routine into lining up with the comment at the beginning of the line, and not the comment which you're currently modifying.
Which version of emacs are you using? My emacs 22 has this problem, but on another machine with emacs 23 does not. This is probalby due to some "electric" indentation. Try M-x describe-key RET RET and also M-x describe-mode to get a nice place to start searching for clues. There is also http://doxymacs.sourceforge.net/ but I have not tesed it personally.