rust/tests/ui/parser/bad-escape-suggest-raw-string.rs

fn main() {
    let ok = r"ab\[c";
    let bad = "ab\[c";
    //~^ ERROR unknown character escape: `[`
    //~| HELP for more information, visit <https://static.rust-lang.org/doc/master/reference.html#literals>
    //~| HELP if you meant to write a literal backslash (perhaps escaping in a regular expression), consider a raw string literal
}
suggest using raw string literals when invalid escapes appear i'd guess about 70% of "bad escape" cases occur when someone meant to use a raw string literal because they're passing it directly to Regex::new(). this emits an advisory (Applicability::MaybeIncorrect) help: suggestion to the user that they use an r"" string, on top of the normal notes about looking at the string literal documentation/spec. 2022-02-14 13:21:43 -06:00			`fn main() {`
			`let ok = r"ab\[c";`
			`let bad = "ab\[c";`
			//~^ ERROR unknown character escape: `[`
			`//~\| HELP for more information, visit <https://static.rust-lang.org/doc/master/reference.html#literals>`
			`//~\| HELP if you meant to write a literal backslash (perhaps escaping in a regular expression), consider a raw string literal`
			`}`