Emacs newbie here. I have recently switched to (Doom) Emacs and decided to add syntax highlighting to V files. There's already a mode that does that (vlang-mode), but I didn't like it, so I decided to make my own one. The problem is, that, as you probably know, Emacs' regex doesn't support lookaround, which I find essential for stuff like (proper) function higlighting, among others.
So, I have found info about Font Lock mode and (in general words) how to use it. Also, I found a solution to regex problem in using visual-regexp-steroids. The only problem is, I can't figure out how to apply highlighting to regions that it finds.
Links to learning resources would be appreciated.
Related
I'm trying to write a new emacs mode for a new template c-like language, which I have to use for some academic research.
I want the code to be colored and indented like in c-mode, with the following exceptions:
The '%' is not used as an operator, but as the first character in some specific keywords (like: "%p", "%action", etc.)
The code lines do not end with a semicolon.
Is it possible to create a derived-mode (from c-mode) and set it to ignore the original purposes of '%' and ';'? Is it possible to make the feature of "automatic-indentation after pressing RET" work without ';'?
Are there similar modes for similar languages (with '{}' brackets, but without semicolons) that I could try to patch?
Should I try to write a major mode from scratch?
I thought about patching the R-mode from http://ess.r-project.org/, but this mode does not support comments of the form "/* comment */".
The most important feature that I'm looking for is the brackets-indentation, i.e. indenting code inside a '{}' block after pressing RET (and without the extra-indentation after lines that do not end with ';'). Partial solutions will help too.
More generally, CC-mode has been extended and generalized over time to accomodate ever more languages, and the latest CC-mode is supposed to be reasonably good at isolating the generic code from the language-specific code. So take a look at some of the major modes that use CC-mode (e.g. awk-mode), and get in touch with CC-mode's maintainer who will be able to help you figure out hwo to do what you want.
If you don't mind something really simple, you can look at Gosu mode. Gosu is a language that has curly braces and no semi-colons, so you should be all set for your minimum. It also uses the same comment syntax as C.
The implementation of the mode for it is really simple and based on generic mode, so modifying it to work the way you want should be easy. It is not based on C-mode.
This is what I used to make a mode for the language I was working on for my compilers class, and it was really easy even with limited elisp experience. On the other hand, the indentation is fairly simple--it works for most code, but is not as complete as C-mode's.
Check out arduino-mode: https://github.com/bookest/arduino-mode/blob/master/arduino-mode.el
It is a C based mode that uses the cc-mode features to quickly create something very useful and unique to arduino programming. Using this as a simple template should help a lot.
There are several questions on SO about how to get code folding in emacs, without having to add any special characters like "markers" in the comments for example. Someone said that there was "no perfect solution."
It seems that it could be done by parsing the source of the program being written and look for matching parenthesis or bracket, or to do it based on indentation. You could also use a combination of scripts that use different methods.
So why is it commonly accepted that there is no "perfect" and straightforward way to get code-folding in emac? Is there something in emacs or its architecture that makes it hard to program? If it were easy, after so many years of smart people using emacs you would think that someone would have wrote it.
You should play with Hideshow (hs-minor-mode) combined with fold-dwim.el. It does exactly what you suggested -- looks for matching braces/parens, and can be set up to fall back on the indentation.
There's a robust folding solution out there for most common languages, and if there isn't, all the folding packages are highly customizable. In fact, the only downside is the proliferation of folding methods (fold-dwim helps quite a bit with that); I used to think that because nobody could point me to a definitive solution, folding was hard or impossible — in fact, the opposite is true. You just have to experiment a little to see what works best for you.
I have used folding.el (e.g. to group stuff in my .emacs), outline-minor-mode, and now Hideshow. There's some chance that none of them would work exactly the way you want right out of the box (e.g. you might need to set up an outline regex, or define folding marks for folding.el), but it turns out to be easy. The default keybindings can be somewhat baroque, but this is remedied by fold-dwim and/or hideshow-org (highly recommended for Hideshow, cf the Emacswiki hideshow page; you can also mimic hideshow-org's behavior for other folding modes with some quick-and-dirty elisp and fold-dwim). Once you figure out your preferred setup, just turn it on automatically via hooks or buffer-local variables, and watch your code fold away :)
You should look into CEDET. It does code-folding just fine, and many other fancy features that you're probably looking for if you're switching from an IDE to Emacs.
http://cedet.sourceforge.net/
Specifically, look for `global-semantic-tag-folding-mode'
You don't need anything extra, just enable outline-minor-mode for file types you want to fold.
But in fact, there ARE various solutions for Emacs; I have listed some of them (those I have happened to come across) at http://en.wikipedia.org/w/index.php?title=Code_folding&oldid=375300945#cite_note-2.
Though, there are things I'm missing: in some cases, I'd like to combine several mechanisms: for example, for markdown, I'd like to use outline-based folding (for sections) and indentation-based folding (for quotations, code blocks etc.) -- in order not bother with implementing a complete parser for markdown.
Here they are:
Token-based folding in Emacs
Token-based folding in Emacs is impemented by the folding minor mode.
Indentation-based folding in Emacs
One can use the set-selective-display function in Emacs to hide lines based on the indentation level, as suggested in the Universal code folding note.
Syntax-dependent folding in Emacs
Syntax-dependent folding in Emacs is supported by:
the outline and allout modes
for special dedicated "outline"-syntaxes;
by the hideshow minor mode for some programming languages;
also,
by the semantic-tag-folding minor mode and the
senator-fold-tag command for
syntaxes supported by semantic,
as well as by doc-mode for JavaDoc or Doxygen comments,
by
TeX-fold-mode
sgml-fold-element command,
nxml-outln library
in the corresponding language-specific modes, and possibly in other modes for particular syntaxes.
Several folding mechanisms are unified by the
fold-dwim interface.
See also http://www.emacswiki.org/emacs/CategoryHideStuff.
Folding of user-selected regions in Emacs
Folding of user-selected regions in Emacs is implemented by the hide-region-hide command.
I have been using folding-mode for quite some time. With auto-insert template and abrevs it works quite well for me for for some nice bricks of code.
Being able to produce the buffer folded (for printing/emailing) has always been a desire of mine. Some of my folding tags are for secure / password hiding.
I know this is a bit old but for me origami.el works perfectly well out of the box.
Yes Finally code folding is there in emacs. Try yafolding present at melpa.org package library.
I am switching to Emacs from TextMate. One feature of TextMate that I would really like to have in Emacs is the "Find in Project" search box that uses fuzzy matching. Emacs sort of has this with ido, but ido does not search recursively through child directories. It searches only within one directory.
Is there a way to give ido a root directory and to search everything under it?
Update:
The questions below pertain to find-file-in-project.el from Michał Marczyk's answer.
If anything in this message sounds obvious it's because I have used Emacs for less than one week. :-)
As I understand it, project-local-variables lets me define things in a .emacs-project file that I keep in my project root.
How do I point find-file-in-project to my project root?
I am not familiar with regex syntax in Emacs Lisp. The default value for ffip-regexp is:
".*\\.\\(rb\\|js\\|css\\|yml\\|yaml\\|rhtml\\|erb\\|html\\|el\\)"
I presume that I can just switch the extensions to the ones appropriate for my project.
Could you explain the ffip-find-options? From the file:
(defvar ffip-find-options
""
"Extra options to pass to `find' when using find-file-in-project.
Use this to exclude portions of your project: \"-not -regex \\".vendor.\\"\"")
What does this mean exactly and how do I use it to exclude files/directories?
Could you share an example .emacs-project file?
I use M-x rgrep for this. It automatically skips a lot of things you don't want, like .svn directories.
(Updated primarily in order to include actual setup instructions for use with the below mentioned find-file-in-project.el from the RINARI distribution. Original answer left intact; the new bits come after the second horizontal rule.)
Have a look at the TextMate page of the EmacsWiki. The most promising thing they mention is probably this Emacs Lisp script, which provides recursive search under a "project directory" guided by some variables. That file begins with an extensive comments section describing how to use it.
What makes it particularly promising is the following bit:
;; If `ido-mode' is enabled, the menu will use `ido-completing-read'
;; instead of `completing-read'.
Note I haven't used it myself... Though I may very well give it a try now that I've found it! :-)
HTH.
(BTW, that script is part of -- to quote the description from GitHub -- "Rinari Is Not A Rails IDE (it is an Emacs minor mode for Rails)". If you're doing any Rails development, you might want to check out the whole thing.)
Before proceeding any further, configure ido.el. Seriously, it's a must-have on its own and it will improve your experience with find-file-in-project. See this screencast by Stuart Halloway (which I've already mentioned in a comment on this answer) to learn why you need to use it. Also, Stu demonstrates how flexible ido is by emulating TextMate's project-scoped file-finding facility in his own way; if his function suits your needs, read no further.
Ok, so here's how to set up RINARI's find-file-in-project.el:
Obtain find-file-in-project.el and project-local-variables.el from the RINARI distribution and put someplace where Emacs can find them (which means in one of the directories in the load-path variable; you can use (add-to-list 'load-path "/path/to/some/directory") to add new directories to it).
Add (require 'find-file-in-project) to your .emacs file. Also add the following to have the C-x C-M-f sequence bring up the find-file-in-project prompt: (global-set-key (kbd "C-x C-M-f") 'find-file-in-project).
Create a file called .emacs-project in your projects root directory. At a minimum it should contain something like this: (setl ffip-regexp ".*\\.\\(clj\\|py\\)$"). This will make it so that only files whose names and in clj or py will be searched for; please adjust the regex to match your needs. (Note that this regular expression will be passed to the Unix find utility and should use find's preferred regular expression syntax. You still have to double every backslash in regexes as is usual in Emacs; whether you also have to put backslashes before parens / pipes (|) if you want to use their 'magic' regex meaning depends on your find's expectations. The example given above works for me on an Ubuntu box. Look up additional info on regexes in case of doubt.) (Note: this paragraph has been revised in the last edit to fix some confusion w.r.t. regular expression syntax.)
C-x C-M-f away.
There's a number of possible customisations; in particular, you can use (setl ffip-find-options "...") to pass additional options to the Unix find command, which is what find-file-in-project.el calls out to under the hood.
If things appear not to work, please check and double check your spelling -- I did something like (setl ffip-regex ...) once (note the lack of the final 'p' in the variable name) and were initially quite puzzled to discover that no files were being found.
Surprised nobody mentioned https://github.com/defunkt/textmate.el (now gotta make it work on Windows...)
eproject has eproject-grep, which does exactly what you want.
With the right project definition, it will only search project files; it will ignore version control, build artifacts, generated files, whatever. The only downside is that it requires a grep command on your system; this dependency will be eliminated soon.
You can get the effect you want by using GNU Global or IDUtils. They are not Emacs specific, but they has Emacs scripts that integrate that effect. (I don't know too much about them myself.)
You could also opt to use CEDET and the EDE project system. EDE is probably a bit heavy weight, but it has a way to just mark the top of a project. If you also keep GNU Global or IDUtils index files with your project, EDE can use it to find a file by name anywhere, or you can use `semantic-symref' to find references to symbols in your source files. CEDET is at http://cedet.sf.net
For pure, unadulterated speed, I highly recommend a combination of the command-line tool The Silver Searcher (a.k.a. 'ag') with ag.el. The ag-project interactive function will make an educated guess of your project root if you are using git, hg or svn and search the entire project.
FileCache may also be an option. However you would need to add your project directory manually with file-cache-add-directory-recursively.
See these links for info about how Icicles can help here:
find files anywhere, matching any parts of their name (including directory parts)
projects: create, organize, manage, search them
Icicles completion matching can be substring, regexp, fuzzy (various kinds), or combinations of these. You can also combine simple patterns, intersecting the matches or complementing (subtracting) a subset of them
When I run Emacs command ispell-buffer on an Emacs buffer which is in the LaTeX mode, ispell checks spelling also inside math expressions.
I'd very much like to disable this. Is there an easy way to do it?
I've read about detex but detex does not seem to be integrated into Emacs.
It shouldn't do this, if you are using latexisms (eg. \[ ... \], equation environments, &c) to invoke math mode. Check the contents of ispell-tex-skip-alists; cf. section 6 of the ispell FAQ for what kind of thing should be there.
You can use $..$, $$..$$ to mark out maths using ispell-tex-skip-alists, but beware getting them out of kilter...
Postscript
Check also the value of the ispell-parser variable: this should be 'tex, otherwise ispell will not look for $...$ and $$...$$ regions.
Yes, you can: install aspell instead of ispell, and use flyspell with it.
This doesn't answer your question directly, but I have found Flyspell, an on-the-fly spell checker, incredibly useful when editing LaTeX documents. It still spellchecks inside equations, but it is much easier to ignore a few extra red underlines than ispell's interactive commands.
You may know this, but you can press A during spell checking to add a word to the buffer-local dictionary (that's capital A, lowercase a adds it to the global dictionary). It's not ideal, but this is how I usually suppress spell-checking of technical terms and variable names, etc., in my LaTeX documents.
This AUCTeX mailing list thread : "spell checker (ispell-buffer) complains about products in math modes" has some workarounds and the answer demonstrates how to use ispell-tex-skip-alists.
Another approach is to use ispell-skip-region-alist. The following example is to exclude org-mode src blocks:
(add-to-list 'ispell-skip-region-alist '("#\\+begin_src". "#\\+end_src"))
I use emacs to edit most of my answers for SO, and although I use longlines-mode (I have not upgraded to emacs 23 because of some critical bugs that don't look like being fixed any time soon), I can't find a way to get longlines-mode to respect the indentation used for Markdown. I would really like to fix this, but I want it for an ordinary buffer, not for org-mode (as already answered).
Does anybody have suggestions on how I can get longlines-mode to indent wrapped lines? I am definitely willing to try hacking the Emacs Lisp, although my Emacs Lisp is pretty rusty...
I just looked through the source code of longlines.el. There doesn't seem to be any hook there to have the wrapped lines indented. If you want to do this, you'll need to write a bit of elisp (and, more importantly, understand all of the functions for doing text-properties.)