JDK 8 code review request for initial unsigned integer arithmetic library support

[Ulf Zibis]

Am 19.01.2012 07:43, schrieb Eamonn McManus:
> Ulf Zibis writes:
> > What about:
> >  private static final BigInteger BEYOND_UNSIGNED_LONG = BigInteger.valueOf(1).shiftLeft(64);
> >  private static BigInteger toUnsignedBigInteger(long i) {
> >      BigInteger result = BigInteger.valueOf(i);
> >      if (i < 0L)
> >          result = result.add(BEYOND_UNSIGNED_LONG);
> >      return result;
> >  }
>
> That's a nice idea! But the problem is that it would mean that BigInteger.class would be loaded as 
> soon as Long.class is, which I think is undesirable.
Thanks for the critic. I didn't see that.
The problem could be easily avoided if method toUnsignedBigInteger(long i) would be moved to class 
BigInteger as unsignedValueOf(long i), as I additionally noted in my last post.

> However it does make me think that we could change...to this:
>
>     if (i >= 0L) {
>         return BigInteger.valueOf(i);
>     } else {
>         return BigInteger.valueOf(i & Long.MAX_VALUE).setBit(63);
>     }
Another nice idea!
But again, moving the entire method to BigInteger would additionally avoid to clown around with the 
available BigInteger's public APIs. Having the method at BigInteger would allow elegant direct 
access to the private value fields.

-Ulf