Function flatten_str 

pub fn flatten_str(s: impl AsRef<str>) -> String

Normalizes a string by performing ASCII transliteration and converting to lowercase.

This uses the [unidecode] crate to approximate non-ASCII characters with their closest ASCII equivalents, and then converts the entire string to lowercase. Then, remove any non-alphanumeric character and consecutive whitespaces, returning the trimmed string.

Examples

let text = "Héllö Wörld! (-123) ";
let flattened = flatten_str(text);
assert_eq!(flattened, "hello world -123");