I'd like to add comments to a major mode that I use that doesn't currently support them. The only examples I can find online show how to write single-line comments, but I need paired delimiters.
What do I need to change?
I ended up digging in to the elisp of the package that I was working with. The problem is that if you add
(setq comment-start "FOO")
(setq comment-end "BAR")
to your-mode-hook, then, when you switch to another language that defines comment-start but not comment-end, then you end up with comment-end sticking from the other mode. For example, your python-mode comments look like:
# def my_func(): BAR
which definitely isn't what you want. In order to fix that, use the following:
(add-hook 'your-mode-hook
(lambda ()
(set (make-local-variable 'comment-start) "FOO")
(set (make-local-variable 'comment-end) "BAR")))
and it won't clobber other modes' comment-end.
Related
I am trying to change the default font face for preprocessor directives #define and #include without using the font-lock-preprocessor-face.
Instead I want to use the font-lock-add-keywords method and regular expressions.
I also want this to apply to assembly and C modes only.
You shouldn't go to these measures if all you want to
do is to redefine font-lock-preprocessor-face for c-mode.
The reason is that font-lock already uses regex and it's
already slow. And now you would parse the exact same source
the second time with the exact same regex.
I used to use some custom regexes to fontify C++, but switched it off
after a year because it was slowing me down.
You can check how slow it is by opening a 50k source
and using C-v a bunch of times.
Now try again with find-file-literally - and it's fine.
Do this instead:
(make-face 'c-preprocessor-face)
(set-face-background 'c-preprocessor-face "blue")
(set-face-foreground 'c-preprocessor-face "yellow")
(add-hook 'asm-mode-hook
(lambda ()
(set (make-local-variable
'font-lock-comment-face)
'c-preprocessor-face)))
(add-hook 'c-mode-hook
(lambda()
(set (make-local-variable
'c-preprocessor-face-name)
'c-preprocessor-face)))
Have you looked at my comment and answer to your previous question, which was essentially the same question as this current thread?
face font in c-mode when adding new keyword
When I am using emacs to edit a latex document the paragraph fill (Esc-q) does not do what I want. For example, something like:
The component \vn{%vec} is not similar to
When I use fill I get:
The component \vn{%vec} is not
% similar to
That is, emacs is taking "%" to be a comment character and filling the paragraph accordingly. However, "\vn" is a macro of mine that sets text in texttt mode and here "%" is simply a regular printable character so the paragraph fill has done things incorrectly.
So what I want is for paragraph fill to be the same it is as in text-mode. That is, no indentation and no adding extra characters. But I don't want to have to toggle between text-mode and latex-mode every time I want to paragraph fill. Is there any way to do this?
Thanks for the help. -- David
PS: Yes, I do know that if there are real comments at the end of lines then the test-mode fill will not do things correctly. But I never put comments at the end of lines so this will never bother me.
I found the solution. I put this in my init.el file:
(add-hook 'latex-mode-hook '(lambda() (setq comment-start nil)))
(add-hook 'tex-mode-hook '(lambda() (setq comment-start nil)))
(add-hook 'latex-mode-hook '(lambda() (setq fill-indent-according-to-mode nil)))
(add-hook 'tex-mode-hook '(lambda() (setq fill-indent-according-to-mode nil)))
I love emacs but the documentation (or lack thereof) can sometimes drive me crazy... :).
You can try:
(setq comment-start nil)
to handle this specific case.
What you're trying to fix is a symptom of the real problem -- latex-mode is
naively marking code after "%" as comment.
Does installing auctex-mode fix your problem?
I was reading an article about well-formatted Git commits, and I was wondering how I could apply some of the rules to the Magit log mode.
It seems to use 3 major modes simultaneously: Magit, Log, Edit.
So how would I get just those modes, when used together, to hard-wrap at 72 characters automatically?
In answer to the original stated question, if you have a single function to add to numerous hook variables, you could do it like this:
(defun my-add-to-multiple-hooks (function hooks)
(mapc (lambda (hook)
(add-hook hook function))
hooks))
(defun my-turn-on-auto-fill ()
(setq fill-column 72)
(turn-on-auto-fill))
(my-add-to-multiple-hooks
'my-turn-on-auto-fill
'(text-mode-hook
magit-log-edit-mode-hook
change-log-mode-hook))
Not the best example, perhaps, but I have something similar for some common behaviours I want enabled in programming modes, of which there are a great many more to list.
Emacs modes have "base modes" which is to say bade modes. For example python-mode extends prog-mode which itself extends fundamental-mode. All modes extend fundamental-mode. So to hook python-mode plus c-mode but not text-mode, you could hook prog-mode.
There can be only one major mode in Emacs buffer (unless you are using something like MMM or MuMaMo). In your case that one major mode is magit-log-edit-mode, whose name consists of three words ("Magit Log Edit"). You can just add to it whatever hook you like:
(defun my-turn-on-auto-fill ()
(setq fill-column 72)
(turn-on-auto-fill))
(add-hook 'magit-log-edit-mode-hook 'my-turn-on-auto-fill)
In general, you could define your own function, say my-common-hook and add it to all the major modes, for example:
(defun my-common-hook ()
... do stuff ...
)
(add-hook 'one-mode-hook 'my-common-hook)
(add-hook 'another-mode-hook 'my-common-hook)
(add-hook 'a-third-mode-hook 'my-common-hook)
Just seeing this now, but here's what I've done. The end result is that i want to do the following:
(hook-up-modes my-lisps 'standard-lisp-environment).
To do this, i define the following defvars.
(defvar my-lisps "clojure lisp emacs-lisp cider-repl")
(defun standard-lisp-environment ()
(paredit-mode 1)
(rainbow-delimiters-mode 1)
(eldoc-mode 1))
I want to have lisp append -mode-hook to the lisps i use so i have the following:
(defun append-suffix (suffix phrases)
"take SUFFIX and append it to each of the PHRASES."
(mapcar #'(lambda (phrase) (concat phrase suffix)) phrases))
so that ("clojure" "lisp") => ("clojure-mode-hook" "lisp-mode-hook").
Now that we could easily have these, we need their reader symbols, which we easily get from
(defun symbols-from-strings (strings)
"Given a list of strings, get their symbol values"
(mapcar #'intern strings))
And then finally we have the similar form posted above:
(defun multiple-mode-add-hook (modes hook)
"Given a list of x-mode-hook symbols in MODE, add the HOOK to them."
(mapc (lambda (mode) (add-hook mode hook)) modes))
These all operate on the type that makes sense for them, list of strings, list of symbols 'blah-mode-hook, etc. So now we need a nice user facing function that we can work with.
(defun hook-up-modes (strings hook)
(let ((modes (symbols-from-strings
(append-suffix "-mode-hook" (split-string strings)))))
(multiple-mode-add-hook modes hook)))
Now this should be pretty legible: We create our modes from a space delimited list of strings and apply the hook to it. Also, since I've defined a standard-lisp-environment, all my lisps behave similarly, and I can easily remove the hook later if I like. Then the code that actually does work is the super simple phrase
(hook-up-modes my-lisps 'standard-lisp-environment).
(dolist (mode-hook '(org-mode-hook
term-mode-hook))
(add-hook mode-hook (lambda () (display-line-numbers-mode 0))))
I was wondering if anyone can provide me with some help on minifying my .emacs file.
Currently I have it set up where each language I use have a custom tab, for example, if I have a hook for Java, it would look like this.
;; Java Hook
(defun e-java-mode-hook ()
(setq tab-width 4)
(setq indent-tabs-mode t)
(define-key java-mode-map (kbd "") 'java-insert-tab))
(defun java-insert-tab (&optional arg)
(interactive "P")
(insert-tab arg))
(add-hook 'java-mode-hook 'e-java-mode-hook)
And if I were to add another language like CSS or JavaScript, I would add another hook for CSS and another hook for JavaScript. So I was wondering if there's a global way of setting it so it would apply to any and all language?
I am currently running GNU Emacs 23.2.1 on Windows 7.
I agree with Tyler; although it's a bit complicated, you would be better off in the long run if you try to understand and customize the default indentation features. The Emacs Wiki has good resources, and there are other relevant Q&As here on Stack Overflow.
Binding the tab key to insert-tab means you completely lose the benefit of the likes of indent-region, and any other intelligent behaviour that a major mode might offer.
To address your specific questions regardless, however:
1) If you are defining (java-insert-tab) and (css-insert-tab) and (javascript-insert-tab) etc, and they all do exactly the same thing... well, hopefully you can see that you don't actually need more than one of those functions. Just give it a more generic name, and re-use it.
2) (local-set-key ...) does the same thing as (define-key (current-local-map) ...), which means you can also have a single generic function to override the tab keybinding, regardless of the major mode.
(defun my-coding-config ()
(setq tab-width 4)
(setq indent-tabs-mode t)
(local-set-key (kbd "<tab>") 'my-insert-tab))
(defun my-insert-tab (&optional arg)
(interactive "P")
(insert-tab arg))
Then you just need to add my-coding-config to each applicable mode hook variable. If there are a lot of them, you might wrap it up in a list like this:
;; Use my coding hook for all programming modes
(mapcar
(lambda (language-mode-hook)
(add-hook language-mode-hook 'my-coding-config))
'(java-mode-hook
javascript-mode-hook
css-mode-hook
...))
3) If you look at C-h v tab-width RET and likewise for indent-tabs-mode, you'll notice that they both say "Automatically becomes buffer-local when set in any fashion."
As an alternative to the customize interface already mentioned, you can use (set-default 'indent-tabs-mode t) to establish the default value for such variables. In the absence of code which sets a buffer-local value, all of your buffers will use the default, which might help you to avoid writing unnecessary mode hooks.
I'm not sure what you're trying to do. If you want to set the tab-width to 4 spaces globally, then you can do that using the customize command:
M-x customize-variable tab-width <ret>
Any changes you make to tab-width in customize will be applied globally. So you won't need to set it individually for each mode with hooks.
If you have different settings you want to apply to different modes, you will necessarily have to have code specific for each mode in your .emacs.
More generally, it looks like you're trying to build your own custom tab insertion commands - does the built-in indentation not do what you need? I think it will be easier to customize the indentation settings in Emacs than to manually insert tabs where you want them.
If you haven't already, take a look at the manual section on indentation and see if you might be able to do what you need without a lot of extra hooks:
C-h r m Indentation
(that is: h-elp, r-ead the manual, m-enu item Indentation)
or:
(info "(emacs)Indentation")
espect.el is doing exactly what you want.
From the docs:
This mode makes it easy to configure settings for individual
buffers with a concice and extensible mini-language. It abstracts
away common configuration selection tasks, like checking the mode
or filename, into a simple declarative syntax. Declare conditions;
run a function when the new buffer matches them. This makes it
easy to do things like turn on flyspell-prog-mode for your favorite
programming languages, or make all text-mode buffers ending in .mkn
have special properties.
This question is related to another one, Emacs :TODO indicator at left side. I recently came across a minor mode I like a lot called FixmeMode. It supports auto highlighting of TODO marks, and navigating between them. However, I think it makes more sense to recognize the "TODO" strings only in comments, rather than polluting the whole file. Is it possible?
Check out the library fic-mode.el, it has been verified in C++ and Emacs-Lisp.
It was written specifically to answer this question.
The installation is like any standard package:
(require 'fic-mode)
(add-hook 'c++-mode-hook 'turn-on-fic-mode)
Though Wei Hu did ask for an easy way to add it to multiple modes, so here goes:
(defun add-something-to-mode-hooks (mode-list something)
"helper function to add a callback to multiple hooks"
(dolist (mode mode-list)
(add-hook (intern (concat (symbol-name mode) "-mode-hook")) something)))
(add-something-to-mode-hooks '(c++ tcl emacs-lisp) 'turn-on-fic-mode)
It's possible but quite a bit trickier. Fixme mode uses font-lock to do its highlighting, so it works on an as-you-type basis to highlight the keywords. Font-lock hooks in at a very low level, basically running after every change is made to the buffer's contents. It is highly optimized, though, which allows it to appear instantaneous on modern computers.
The TODO indicator in the left fringe is static. Execute the function and all current TODO's are highlighted; change the buffer (adding or removing TODO's) does not change the fringe indicator; that's only changed when the function runs again.
Your approach would have to get into syntax tables, determining first when you're in a comment and then looking for the keywords. The tricky part comes in doing this interactively (i.e. as you type). You should be able to hook into the font-lock constructs to do this, but the function you provide to search for the comment syntax table and then for the keywords better be very efficient, as it will be run each and every time a buffer changes (though it will only run on the changed region, I think). You would want to stuff all of this in font-lock-syntactic-keywords rather than font-lock-keywords because the syntactic-keyword pass happens before the syntactic pass (which happens before the keyword pass), and you need to set TODO inside comments before comments themselves are set.
Sorry it's not a full working-code answer.....
Maybe this will help: there's a fn c-in-literal in
cc-mode, and a similar csharp-in-literal in csharp mode. The
return value is c if in a C-style comment, c++ if in a C++
style comment. You could add that to the code at
Emacs :TODO indicator at left side
to get what you want.
(defun annotate-todo ()
"put fringe marker on TODO: lines in the curent buffer"
(interactive)
(let (lit)
(save-excursion
(goto-char (point-min))
(while (re-search-forward "TODO:" nil t)
(progn
(setq lit (c-in-literal)) ;; or csharp-in-literal
(if (or (eq lit 'c) (eq lit 'c++))
(let ((overlay (make-overlay (- (point) 5) (point))))
(overlay-put overlay 'before-string
(propertize "A"
'display
'(left-fringe ;; right
horizontal-bar
better-fringes-important-bitmap))))))))))
https://github.com/tarsius/hl-todo seems to do exactly what you want. I just tried it and love it.