rfc5646langtag top-level property
final
Implementation
final rfc5646langtag = rule(
'langtag',
concatenation([
rfc5646language,
optionalSequence([literal('-'), rfc5646script]),
optionalSequence([literal('-'), rfc5646region]),
variableRepetition(concatenation([literal('-'), rfc5646variant])),
variableRepetition(concatenation([literal('-'), rfc5646extension])),
optionalSequence([literal('-'), rfc5646privateuse]),
]),
);