Function `domain_to_ascii_from_cow`

pub fn domain_to_ascii_from_cow(domain: Cow<'_, [u8]>, ascii_deny_list: AsciiDenyList) -> Result<Cow<'_, str>, Errors>

The domain to ASCII algorithm; version accepting and returning a Cow.

Most applications should be using this function or domain_to_ascii_cow rather than the sibling functions, and most applications should pass AsciiDenyList::URL as the second argument. Passing AsciiDenyList::URL as the second argument makes this function also perform the forbidden domain code point check in addition to the domain to ASCII algorithm.

Return the ASCII representation a domain name, normalizing characters (upper-case to lower-case and other kinds of equivalence) and using Punycode as necessary.

This process may fail.