Line exceeded maximum length warning caused by CRLF

[iliekturtles]

The code block below gives the following warning when the file is saved with Window's native CRLF line ending: Rustfmt failed at S:\uom\src\system.rs:143: line exceeded maximum length (maximum: 100, found: 101) (sorry). Saving the file with a LF line ending silences the warning. rustfmt must be counting the CR (\r) as part of the line length.

                impl<$($name,)+ $($symbol,)+ V> $crate::stdlib::ops::$Trait<BaseUnits<$($name,)+ V>>

[ghost]

@iliekturtles It indeed does : https://github.com/rust-lang-nursery/rustfmt/blob/master/src/lib.rs#L473

However, since there's a special case for \r, it seems it's done on purpose. I don't know why, not familiar with this package, let's hope someone more experienced with this package can help us :)

[iliekturtles]

After digging through the blame I see that commit 598fcdd, which references #717, added the line_len increment. This brings up a bigger question about why len_utf8 is being used which reports character width in bytes. What should really be counted graphemes? How does that handle combining characters?

[ghost]

@iliekturtles Good catch ! It actually does handle them quite poorly.

This code (length of the line is 70 grapheme-long):

fn main() {
    println!("ééééééééééééééééééééééééééééééééééééééééééééééééééééé");
}

produces :

Rustfmt failed at combined_characters.rs:2: line exceeded maximum length (maximum: 100, found: 123) (sorry)

Let's open an issue for that and link it to this one ?

[nrc]

The special case code for \n should also count \r. That should be an easy fix.

Rustfmt just doesn't handle unicode > 8 bits well at all (currently the oldest issue in this repo - #6).

[ghost]

Thanks for the info @nrc . I'll crate a PR accordingly to your suggestion