I'm writing an Emacs plugin and ran into a challenge. I have a command that formats a region to my specifications. It's perl, and it does somethings I don't want it to try to do while I'm editing, like this:
my $foo = "foo";
my $fooer = "fooer";
becomes
my $foo = "foo";
my $fooer = "fooer";
However, I am working in a code repository full of code that I have not written that I do not want to change.
I have written a command that operates on a region and performs exactly as expected, but I want to add a hook to before-save to format blocks there. Is there a way to get regions of changes, but ignore unchanged regions?
I've considered using highlight-changes functionality, but had a hard time finding anything usefull. I've also thought about trying to use the git blame, but that seems like it would take a lot of time to do something simple.
Is there Elisp functionality to get only modified regions of a buffer? I know ws-butler only formats modified lines, and the Emacs wiki claims it 'Leverages highlight-changes-mode to track modified lines.', but I read the source for ws-butler and was just confused by a total lack of any mention of highlight-changes-mode.
Related
I've been using Org-mode a few months, and as I customize Emacs, I'm having a lot of difficulty finding documentation on how to specifically customize various variables.
Example: I've successfully set up archiving, but want to customize the org-archive-save-context-info variable to reduce the info that's archived along with the task. I do not want to do this per-file, but in my config file. Despite my best efforts, I don't see documentation on syntax and parameters for customizing this.
I do see some documentation when I customize the variable in the Emacs UI--but I'm looking for documentation so I can see syntax and parameters for customizing this myself via a config file. I can learn it backwards this way (via 'easy customization'): customize a variable, see what Emacs wrote to the config, try tweaking that, etc.
[EDIT] I'm talking about info below the task that appears after archiving, like this:
:PROPERTIES:
:ARCHIVE_TIME: 2018-09-10 Mon 11:24
:ARCHIVE_FILE: ~/Dropbox/logs/capture.org
:ARCHIVE_OLPATH: Tasks
:ARCHIVE_CATEGORY: capture
:ARCHIVE_TODO: DONE
:END:
Is this intentional? Do I just need to 'know ELisp' first? Is the intention that you use the Emacs point-and-click UI to customize things like this? Happy to RTFM if I could find the FM.
Is the intention that you use the Emacs point-and-click UI to customize things like this?
It's certainly intended that you would use the customize interface if you don't know elisp (and you might well choose to use it even if you do).
Do I just need to 'know ELisp' first?
Yes, you'll need at least some familiarity with elisp in order to understand the documentation and be able to write your own config changes. This is because elisp is the configuration language for Emacs, and so the documentation is written in that context. (It wouldn't make sense for basic lisp concepts to be explained and repeated in every piece of documentation which used them.)
That said, many people get by just copying and pasting from config examples -- and you're likely to pick up the basics this way, even if you don't fully understand them. If you're serious about Emacs, though, spending some time to learn about elisp will be hugely beneficial to you in future.
I can learn it backwards this way (via 'easy customization'): customize a variable, see what Emacs wrote to the config, try tweaking that, etc.
That's an entirely reasonable thing to do.
FWIW C-hv org-archive-save-context-info is actually very clear if you have the background understanding.
This variable can be a list of any of the following symbols:
time The time of archiving.
file The file where the entry originates.
ltags The local tags, in the headline of the subtree.
itags The tags the subtree inherits from further up the hierarchy.
todo The pre-archive TODO state.
category The category, taken from file name or #+CATEGORY lines.
olpath The outline path to the item. These are all headlines above
the current item, separated by /, like a file path.
That tells you that you might use the following in your config file:
(setq org-archive-save-context-info '(time file todo))
Happy to RTFM if I could find the FM.
You can start learning about elisp in the "Emacs Lisp Intro" manual, which you should find near the top of the Info directory, or jump to directly with C-hig (eintr) RET. Type h from there if you need to learn how to use the Info reader.
When running emacs calc, typing a prefix key, say 'm', followed by '?' is supposed to show all mode-related commands in the minibuffer as a kind of quick help facility.
For several years I have noticed that this quit working for me. When I hit the '?' the minibuffer flashes the help for a small fraction of a second, then goes blank. I can sometimes see parts of the help text rendered but ususally it blanks too fast to see it.
This does not happen when I run emacs -Q to skip my init file, so it is something in the init file that is the cuplprit.
My init file is quite large. I would like to put something like '(exit)' in different places in my init file to stop processing the init file and see if I can pin down what is causing the problem.
(1) What is the right way to do this?
(2) Anybody else see this problem with the minibuffer in calc?
Good question. The answer is simple: recursively bisect your init file.
Do that by commenting out 1/2 of it, then 3/4, then 7/8,... This is a binary search, and it is very quick, even though it might not seem that way at first. It is systematic, and essentially blind (thoughtless).
To comment out a block of text, use command comment-region. To uncomment a block of text, use C-u with the same command.
Trust me - in no time at all, you will have identified the culprit code, no matter how big your init file is. And if you load other libraries from your init file, and doing the exercise above shows that the culprit code is in one of those libraries, then do the same thing with (a copy of) that library code: recursively bisect it.
After several hours of trying to narrow down the problem, I found the culprit.
When key-chord-mode is set on in calc, the key help facility displays the symptoms I mentioned above.
Would like to keep key-chord enabled globally and disable it in calc-mode, but turning it off in the calc-mode-hook turns it off for all modes. Any ideas?
Anyway, I am closer to figuring out this long-term irritant.
I'd like to use emacs in some kind of batch mode to just render a file with syntax highlighting and exit. Specifically, I want to dump the fontified buffer with ANSI escape codes so that it shows up reasonably syntax-highlighted on my terminal. Is there any way to do this?
The ansi-lpr.el library seems to be kind of along the lines of what I want, but the output isn't colorified. I can't figure out how to get over that final hurdle — there are a lot of modules to digest ANSI escape codes into Emacs text properties (e.g. ansi-color.el) but I haven't found anything that does the reverse. If anyone can point me to something that does, I think I can piece together the rest.
Alternatively, I've seen some hacky approaches like this answer (using script and capturing the output) but in my experiments that approach has seemed unlikely to be fruitful — you get tons of undesirable control sequences mixed in with the highlighted text.
The overarching motivation here is to use emacs in a $LESSOPEN pipe to get syntax highlighting when I page files. In case you're going to say it, I've tried and "just page files in Emacs" is not acceptable for me.
I'm glad to announce a new package, e2ansi, that (hopefully) does what you asked for.
The package provides a command-line tool e2ansi-cat that starts Emacs in batch mode, opens files, syntax highlight them (using font-lock), and creates ANSI-colored versions of the syntax highlighted files.
You can integrate this into less by setting the following variables to, for example:
export "LESSOPEN=|emacs --batch -Q -l ~/.emacs -l bin/e2ansi-cat %s"
export "LESS=-R"
export MORE=$LESS
The end result looks like the following:
You can vary the colors and attributes like bold, underline, and
italics by using a suitable Emacs theme.
The e2ansi package is located at https://github.com/Lindydancer/e2ansi
Personal note
I would like to thank you for posting this question, it directly inspired me to write e2ansi.
When working on different projects, with different people and using different frameworks you often struggle to keep your code compliant to their conventions. Some teams get very strict about naming variables/methods/classes and other things the others make holy wars around the topic. I understand them and I fully support, but as any developer I have my own preference I wish I could code with comfortably. This makes me think whether there is a simple solution.
Are there any tools or editors that can automatically convert code to follow a different standard? I imagine there can be no such smart tool that will support naming conversions, so I'm ok with that, but I really wish to see
foreach($lala as $lalala) {
and not
foreach($lala as $lalala)
{
same goes with statements:
if(I_LIEK_COOKIES) {
eat_cookie();
} else {
toss_cookie();
}
and not
if ( I_LIEK_COOKIES ) {
eat_cookie();
}
else
{
toss_cookie();
}
(note the spaces between and around the parenthesis too)
I won't even mention spaces/tabs, I can convert it in my IDE with a shortcut but it would be awesome.
So the things I would like to get customized are
spaces between parenthesis
tabs/spaces and spaces per tab
mustache brackets on the end of the line or on the new line
always attach mustache brackets to any if/ifelse/else/for/foreach etc.
Some of the extras anyone would appreciate:
Line ending style
Delete extra spaces on the line endings (like sublime text 2 can do on save, but would be great for other IDE/editors)
The perfect workflow would be like this:
I pull from git
The code gets converted to my style
I code stuff
I commit and push
Before everything gets pushed(or even commited) code gets converted to the convention style
Of course, someone may wish not to use git, then it would be simply converted when opening and after saving the file but as I understand it's impossible to do outside of an IDE/editor with a tool of some kind.
Has someone stumbled upon something like that? Could not find anything anywhere but tab/space conversion.
P.S. I wish to mention I'm working with PHP/JS so it's prioritized but I code using other languages on my spare time.
You could store configurations (e.g. vim .vimrcs, Eclipse preferences etc.) in each project's version control repository.
However, I think there's a big problem wrt. converting code when pushing/pulling to/from repositories. If someone reports an issue with your code (e.g. exception at line 100), converting the code when pulling from your repository is going to give you a different line 100. I don't think you can practically operate without working on the exact code that your compatriots are working with.
When viewing piped output to Less, sometimes I'd like to be able to view it in Emacs in order to get syntax highlighting and use emacs commands for searching, marking, copying, etc.
I see that Less has a v command that can be used to open the currently viewed file in $EDITOR. Unfortunately this doesn't work when viewing piped input.
Also, I don't know how to get Emacs to display stdin as a read-only document.
So, is it possible to set up Less with something like v but that pumps the current buffer into Emacs as a read-only file?
Thanks.
If you scroll down in http://www.emacswiki.org/emacs/GnuClient, you'll come to a section titled "Piping data to an Emacs buffer" which may be relevant. Or you can hack up a solution involving emacsclient and temporary files. (link dead).
I found another variant while looking for a duplicate of the dead link: Piping to an emacs buffer with emacsclient which points at code stored on github.
I've formalized the solution here: github e-sink