## Stream: general

### Topic: whitespace in emacs

#### Adam Topaz (Nov 07 2020 at 21:18):

I have found that some lines in my lean files end up with trailing whitespace, after editing them in emacs. This is probably always my fault for adding spaces and not deleting them.

It seems that vscode has some automatic magic that gets rid of these trailing spaces. So if I commit some files with emacs, then make some edits in vscode and commit from vscode, I get a lot of small whitespace only diffs, that I would like to avoid.

Does anyone know of some linter for emacs that gets rid of trailing unnecessary whitespace?

#### Reid Barton (Nov 07 2020 at 21:49):

This isn't exactly what you asked for (and I'm curious too) but global-whitespace-mode will make it pretty obvious if you leave trailing whitespace (or other whitespace infelicities such as tab characters) in your file. I recommend turning off everything related to the display of ordinary spaces and newlines.

#### Simon Hudon (Nov 07 2020 at 21:51):

I have this line in my init.el file:

(add-hook 'before-save-hook 'delete-trailing-whitespace)


#### Simon Hudon (Nov 07 2020 at 21:51):

Instead of highlighting the trailing spaces, it just deletes them every time I save.

#### Adam Topaz (Nov 07 2020 at 22:15):

Thanks! delete-trailing-whitespace works exactly as I expected!

#### Julian Berman (Nov 08 2020 at 00:21):

also also not what you asked for, but pre-commit (https://pre-commit.com/) is very useful, and the trailing-whitespace hook if you configure it will complain at you if you try to commit files with trailing whitespace

#### Adam Topaz (Nov 08 2020 at 00:41):

Does pre-commit work with magit?

#### Simon Hudon (Nov 08 2020 at 00:50):

I haven't had trouble with the two

#### Adam Topaz (Nov 08 2020 at 00:58):

Great! Maybe I'll be able to uninstall vscode soon :eyes:

#### Simon Hudon (Nov 08 2020 at 01:01):

Btw, have you tried VS code with Coq? I hear it's pretty good

No I havent

#### Adam Topaz (Nov 08 2020 at 01:03):

I only played with Coq a little bit, using proof general and coqide

#### Simon Hudon (Nov 08 2020 at 01:07):

Me too. Actually, I started appreciating Coq much more once I tried Proof General. But I hear Proof General is the only one that can't do parallel proof compilation

Last updated: May 13 2021 at 18:26 UTC