Expand description
Domain name finder.
Extracts standalone DNS-style domain names (e.g. example.com,
sub.example.co.uk) whose TLD exists. Anything preceded by @ or ://
is skipped to avoid eating the host part of emails and URLs.
The scanner triggers the finder at every . between an alphanumeric
byte and a letter; the finder walks back to the start of the token and
evaluates it exactly as Finder::find does, remembering a failed
token so its other dots cost nothing.