SieveUtil

Represents a prime factor which we need to keep track of.

The first field 'p' is the prime itself. The 'next' field is the next multiple of the prime that we expect to see.

We use a slightly non-standard compare() function so that the factor with the smallest 'next' field will be the largest.

Reprsents a prime factor which we need to keep track of.

Similar to Factor, but in this case the prime is small enough that it fits in an Int. This means that each of our sieve segments will contain at least one multiple of 'p' if not more. So we can use a slightly more compact data structure.

This class simply wraps an Array[FastFactor]. Its only real purpose is to allow us to lazily initialize our fast factors (which we can only do after constructing our first sieve segment).