Static TEXT_DIRECTION_CODEPOINT_IN_LITERAL

pub static TEXT_DIRECTION_CODEPOINT_IN_LITERAL: &Lint

The text_direction_codepoint_in_literal lint detects Unicode codepoints that change the visual representation of text on screen in a way that does not correspond to their on memory representation.

Explanation

The unicode characters \u{202A}, \u{202B}, \u{202D}, \u{202E}, \u{2066}, \u{2067}, \u{2068}, \u{202C} and \u{2069} make the flow of text on screen change its direction on software that supports these codepoints. This makes the text “abc” display as “cba” on screen. By leveraging software that supports these, people can write specially crafted literals that make the surrounding code seem like it’s performing one action, when in reality it is performing another. Because of this, we proactively lint against their presence to avoid surprises.

Example

#![deny(text_direction_codepoint_in_literal)]
fn main() {
    println!("{:?}", '‮');
}

{{produces}}