We could chance the re in swift to something like "^(inet6:)?\[(?P<address>.*)\](:(?P<port>[0-9]+))?$" so the 'inet6:' part it optional.. then we would support both forms.
We could chance the re in swift to something like "^(inet6: )?\[(?P< address> .*)\](: (?P<port> [0-9]+) )?$" so the 'inet6:' part it optional.. then we would support both forms.