Source code in the ceylon programming language

shared void run() {
	value numbers = "49927398716
	                 49927398717
	                 1234567812345678
	                 1234567812345670";
	for(number in numbers.lines) {
		print("``number`` passes? ``luhn(number)``");
	}
}

shared Boolean luhn(String number) {
	value digits = number
			.reversed
			.map(Character.string)
			.map(Integer.parse)
			.narrow();
	value s1 = sum { 0, *digits.by(2) };
	value s2 = sum {
		0,
		*digits
			.skip(1)
			.by(2)
			.map(curry(times)(2))
			.map((Integer element) => element / 10 + element % 10)
	};
	return (s1 + s2) % 10 == 0;
}