Tabs are 8 characters, and thus indentations are also 8 characters. There are heretic movements that try to make indentations 4 (or even 2!) characters deep, and that is akin to trying to define the value of PI to be 3.
I am in love with this awsome document; I love its guidelines, and coding conventions.
However, when Rust was introduced into the kernel, they butchered these beautiful guidelines, I know it’s hard to look at such heretic actions, but you have to see this:
The default settings of
rustfmt
are used. This means the idiomatic Rust style is followed. For instance, 4 spaces are used for indentation rather than tabs.
How can this even relate to the ideology of the first document? I am deeply saddened by these new rules.
I know this is “The Rust experiment”, but this must be fixed before it’s too late! This has to reach someone.
A counter-argument might be:
The code should be formatted using
rustfmt
. In this way, a person contributing from time to time to the kernel does not need to learn and remember one more style guide. More importantly, reviewers and maintainers do not need to spend time pointing out style issues anymore, and thus less patch roundtrips may be needed to land a change.
And to that I say that rustfmt
is configurable per project, and if it isn’t, then it has to be. Doesn’t something like .editorconfig
exist?
Edit: I think I read enough comments to come up with a conclusion.
At first, forcing another language’s code style upon another sounds backwards, but both styles are actually more similar than I originally though, the kernel’s C
style is just rustfmt
’s default with:
- 80 character line.
- 8-space hard tabs.
- Indentation limited to 3.
- Short local-variable names.
- Having function length scale negatively with complexity.
The part about switch
statements doesn’t apply as Rust replaced them with match
.*
The part about function brackets on new lines doesn’t apply because Rust does have nested functions.
The bad part about bracket-less if
statements doesn’t apply as Rust doesn’t support such anti-features.
The part about editor cruft is probably solved in this day & age.
The rest are either forced by the borrow checker, made obsolete by the great type system, or are just C
exclusive issues that are unique to C
.
I left out some parts of the standard that I do not understand.
This all turned up to be an indentation and line-size argument. Embarrassing!
*: I experimented with not-indenting the arms of the root match
expression, it’s surprisingly very good for simple match
expressions, and feels very much like a switch
, though I am not confident in recommending to people. Example:
match x {
5 => foo(),
3 => bar(),
1 => match baz(x) {
Ok(_) => foo2(),
Err(e) => match maybe(e) {
Ok(_) => bar2(),
_ => panic!(),
}
}
_ => panic!(),
}
My emotions just stopped, so I can now think straight.
There are really only 2 changes that - in my eyes - should be made:
I don’t think a tool like
rustfmt
can affect most of the original guidelines, and it’s generally compatible with the OG style by default.Edit: I - surprisingly - never actually used
rustfmt
, so I will go now and test before I say something stupid.Edit II: I just found this on their repo:
Edit III: I tested
rustfmt
with:It’s great!
We are not stuck to DEC VT100 terminals anymore. It’s okay to have 100 columns of code. And wasting 10% of that space for each indentation? What are you smoking?
As I said before, this standard is older than C itself, and the kernel’s been using it for decades, I shouldn’t have to explain it. Long tabs and short lines boost readability, and restricting indentation to 3 solves the problem. Read my reply to 1rre@discuss.tchncs.de for more context.
Also
rustfmt
didn’t move the string inprintln!("a very long string slice with a static lifetime");
to a new line even when it exceeded a 100 columns, I should seek a solution.Note: The actual string I used was way longer than that.
Hard disagree. 8 spaces is waste and 4 should be industry standard. Tabs should not be used for indentation, but spaces. On the other side, Tabs are configurable, so that’s actually a plus point.
Why? 80 is an old standard with limitations that do not apply today anymore. We have wider screens and higher resolutions. While it makes sense to keep this to be consistent with previous code and language defaults for C, there is no reason to enforce this for the new adopted language, which already has a standard on its own.
And yes rustfmt can be configured and when I started with Rust I changed max_width to 80, just because I was used to it with Python. But there is no benefit doing this in Rust.
deleted by creator
Either you use hard tabs, which you happen to have configured to 8 spaces locally because you’re some sort of masochist, or, if you’re more of a sadist, you use 8 spaces in place or tabs. One of the great things about using hard tabs is that people can configure them to be whatever size they want; 2, 3, or 4 spaces, so specifying a size in your style guide is redundant as they’ll just appear as the pre-configured size to anyone else. The only reason to specify hard tab size is if your style guide is satirical or esoteric, which I guess if you’re specifying 8 spaces it certainly is anyway.
80 character limit is kind of reasonable, but I think the intersection between people who have a low resolution, narrow aspect ratio screen and people who code in rust is significantly lower than C or C++, and it’s unlikely they’ll want a 3-way vertical split in a terminal/editor, so a 100 or even 120 column limit makes more sense in my opinion especially given it doesn’t require editing code that’s already written, but I wouldn’t argue against enforcing 80 for consistency
But how else are you going to enforce a specific line size?(I remembered formatters exist, don’t mind this)I was thinking of something else, something better, but I do not know if it exists, I’ll say it:
The thing I don’t like about space indentation is how you can individually delete and select each space while editing, which is aesthetically unpleasing and error prone, which makes a formatter necessary. Using spaces is also weird in the sense that indentation is supposed to be a block of continuous whitespace, not little things joined together.
However, using tabs creates inconsistent results when copying code to a browser or online view in general.
My idea is: configure your editor - ideally through
.editorconfig
- to interpret 8 continuous spaces as a tab, and display them as such, and when the time comes to save, you tabs are actually saved as 8 spaces, which solves both the aesthetics and portability problem.Is this possible? does this already exist? I do not know.
Edit: I forgot your second paragraph
Maybe it’s because I use 18.5 inches and 1366x768*, but an 80 character long line already makes me shift my eyes in a way I prefer not to. Low line length is just comfortable.
It’s worth mentioning that I recently increased my coding font size to Neovide’s default (from 12 -> 14), which made me realize why people do things like
Ok(())
, sticking parentheses look weird on low font sizes.I believe that limiting indentation - to 3 - makes code better, an opinion I based on the Linux guide and a video with good animations.
*: I only needed to fix it once in the last 10-14 years; I don’t remember anymore. Why change what’s working? it’ll only make playing video games awkward needing to pipe everything through Wine’s FSR.
Speaking of that one repair job, the repairman just replaced all of the monitor’s insides with another model’s, and now I cant tweak brightness or contrast or use anything but auto adjustment.
Edit II:
8 space tabs have been the default since the K&R days.
Tabs being 8 spaces has been the norm since the typewriter (actually not)
Why do people hate them that much nowadays?
Edit III:
Maybe you’re right, I should ignore the sunk cost of reading a 3rd of The Rust Programming Language book, and leave Rust to the cool new generation with their HD displays, and non-DIYed setups)**, and social media usage, and their computers are fast so just write it in javascript and forget about older systems and 3rd world countries and the poor and environment hurting emmisions, and just go learn C. I always felt like I fitted in with people 1 or 2 generations older. (I am not actually going to do that, that’s a joke)
**: BTW, my speaker’s left channel is an old radio that is connected to my speaker’s cable. My left speaker broke when I pushed it off the table, served for a good 8-12 years; I still don’t remember anymore.
I think they can just ban tabs. And do some automatic rejection via… what? Are kernel devs still using email attachment for this?