func graphemeBreakPropertyData( forLine line: String ) -> (scalars: ClosedRange<Unicode.Scalar>, property: Unicode.GraphemeBreakProperty)? { line .match(/([0-9A-F]+)(?:\.\.([0-9A-F]+))?\s*;\s(\w+).*/)? .captures.flatMap { (l, u, p) in guard let property = Unicode.GraphemeBreakProperty(p) else { return nil } let scalars = Unicode.Scalar(hex: l)! ... Unicode.Scalar(hex: u ?? l)! return (scalars, property) } }l, u, p の３要素タプルなのは正規表現パターンと対応しているのか。これはいいなあ。func graphemeBreakPropertyData( forLine line: String ) -> (scalars: ClosedRange<Unicode.Scalar>, property: Unicode.GraphemeBreakProperty)? { line.match { OneOrMore(.hexDigit).capture { Unicode.Scalar(hex: $0) } Optionally { ".." OneOrMore(.hexDigit).capture { Unicode.Scalar(hex: $0) } } OneOrMore(.whitespace) ";" OneOrMore(.whitespace) OneOrMore(.word).capture(GraphemeBreakProperty.init) Repeat(.anyCharacter) }?.captures.map { (lower, upper, property) in let scalars = lower ... (upper ?? lower) return (scalars, property) } }