Proposal: Sameness operators

Joe Darcy Joe.Darcy at Sun.COM
Thu Apr 2 16:13:36 PDT 2009


Mark Thornton wrote:
> Reinier Zwitserloot wrote:
>> BI/BD's comparison methods can't just convert the incoming primitive 
>> to a BI/BD, because NaN and the infinities don't convert, yet the 
>> answer to this expression:
>>
>> Double.NEGATIVE_INFINITY < BigInteger.ZERO
>>
>> should clearly be true. The above plan can make that happen by adding 
>> more logic to BI/BD's compareTo methods.
> The 754R decimal format does include NaN and +-infinite, so perhaps the 
> answer here is to modify Java's BigDecimal to match.

Yes, I actually worked on incorporating the decimal changes into the 
754R draft while I was editor :-)  The "preferred exponent" nomenclature 
in the new 754 standard came from the JSR 13 BigDecimal specification 
work in JDK 5.

> Joe could probably tell us more about the possibility of such a change.

We don't plan to add the non-finite values and negative zero to the set 
of values recognized by BigDecimal.  If someone wanted to do this, I'd 
recommend creating a wrapper around BigDecimal that supported the new 
values and otherwise delegated to an internal BigDecimal.

-Joe



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