/**
* Filter non-primes
*
* @param numbers
*/
private ATermList filterNonPrimes(ATermList numbers) {
ATermList primes = factory.makeList();
numbers = numbers.getNext();
while (!numbers.isEmpty()) {
ATermInt prime = (ATermInt) numbers.getFirst();
numbers = filterMultiples(prime.getInt(), numbers);
primes = primes.append(prime);
}
return factory.makeList(factory.makeInt(1), primes);
}
/**
* Filter multiples of n.
*
* @param n
* @param numbers
*/
private ATermList filterMultiples(int n, ATermList numbers) {
int nr, len = numbers.getLength();
for (int i = 0; i < len; i++) {
ATermInt el = (ATermInt) numbers.elementAt(i);
nr = el.getInt();
if (nr % n == 0) {
len--;
numbers = numbers.removeElementAt(i);
}
}
return numbers;
}