JDK 9 RFR of 8026236: Add PrimeTest for BigInteger [TEST-ONLY]

[Paul Sandoz]

On May 3, 2014, at 6:55 PM, Joe Darcy <joe.darcy at oracle.com> wrote:

> Hi Brian,
> 
> I think the parsePrimes method would be better with a different name since no parsing is occurring anymore.
> 

Yes, and there is no need for the try block.

(The use of BitSet.stream() also reminds me we can implement a spliterator with size estimates based on the words in use, currently the stream() is created from an iterator.)


> I think someone in this test the fact that Integer.MAX_VALUE is a prime should be mentioned in taken advantage of :-)  How about adding another test method which tests some Mersenne primes for primality? [1]
> 
> I'd prefer to see some comments on the primes method briefly explaining it methodology. Would the running time be unacceptable (or memory usage too large) if the limit were set to Integer.MAX_VALUE?
> 

+1 to both of those, although perhaps the former could be done as a second iteration to get this code in?

Also, probably better to create the "NavigableSet<BigInteger> primes" just once in "main", rather than creating it twice for both tests.

Still skeptical about the use of a PRNG in the tests, see my comments in a previous email:

  http://mail.openjdk.java.net/pipermail/core-libs-dev/2014-April/026579.html

Paul.