hexletters top-level property

Rule hexletters
final

Implementation

final hexletters = rule(
  'HEX-LETTERS',
  // alternativeLiterals is case-insensitive by default (RFC 5234 §2.3),
  // so uppercase A–F are matched automatically.
  alternativeLiterals(['a', 'b', 'c', 'd', 'e', 'f']),
);