ANSI escape breaks right to left Strings

[Araxeus]

I tried this code:

fn main() {
    let input = String::from("שלום");

    // ok (no color)
    for ch in input.chars() {
        print!("{}", ch);
    } println!();

    // ok (same color)
    for ch in input.chars() {
        print!("{}", color(ch));
    } println!();

    // not ok (mixed colors)
    for (i, ch) in input.chars().into_iter().enumerate() {
        print!("{}", if i % 2 == 0 { color(ch) } else { color2(ch) });
    } println!();
}

fn color(ch: char) -> String {
    format!("\x1b[93m{}\x1b[0m", ch)
}

fn color2(ch: char) -> String {
    format!("\x1b[96m{}\x1b[0m", ch)
}

I expected to see this happen:

• String order is preserved even if inside different ANSI escapes

Instead, this happened:

• when ANSI codes are mixed, the right to left order is mixed up
  

Meta

rustc --version --verbose:

rustc 1.60.0 (7737e0b5c 2022-04-04)
binary: rustc
commit-hash: 7737e0b5c4103216d6fd8cf941b7ab9bdbaace7c
commit-date: 2022-04-04
host: x86_64-pc-windows-msvc
release: 1.60.0
LLVM version: 14.0.0

[wwylele]

I don't think this has anything to do with rust. Rust doesn't interpret the ANSI escape sequence. It simply puts the string to stdout as-is. It is the terminal that interprets these sequence. This issue should be opened to the terminal implementer (in this particular case for "x86_64-pc-windows-msvc", it is cmd or powershell or whichever terminal you are using)

[Araxeus]

You're right, after some more testing it happens from other sources too

Sadly both cmd and Powershell have this behavior (inside Windows Terminal)

@wwylele out of curiosity, if you try the code above in bash does it work correctly?
I imagine those letters just appear as � for you

[ehuss]

If you are interested, I would also recommend commenting on microsoft/terminal#538 about how ANSI codes interfere with the bidi algorithm.

[Araxeus]

Thanks, I just left a short comment there