On Wed, 21 Jun 2023 16:29:40 GMT, Roger Riggs <rri...@openjdk.org> wrote:
>> In java.time packages, clarify timeline order javadoc to mention "before" >> and "after" in the value of the `compareTo` method return values. >> Add javadoc @see tags to isBefore and isAfter methods >> >> Replace use of "negative" and positive with "less than zero" and "greater >> than zero" in javadoc @return >> The term "positive" is ambiguous, zero is considered positive and indicates >> equality. > > Roger Riggs has updated the pull request incrementally with one additional > commit since the last revision: > > Clarify return values of date time classes > Adding a bit more context, floating-point arithmetic is an approximation to real arithmetic. Real arithmetic has a single zero value. The signed zeros of IEEE 754 floating-point are a computational artifact. More specifically, IEEE 754 floating-point is an approximation to the real numbers extended with infinite values. There are two ways to extend the reals with infinity: affine (signed infinities) and projective (one unsigned infinity). Early drafts of the IEEE 754 standard supported both affine and project infinity, as did the original 8087 floating-point which predated IEEE 754. The final IEEE 754 only supports signed infinities and because there are two infinities, there are two distinguished (but numerically equal) zero values. The floating-point signum methods in the Java math library return a same-signed zero for a zero input; +1.0 is *not* returned for +0.0 and -1.0 is *not* returned for -0.0. While a zero value has a sign bit in its representation, neither zero value is "positive" or "negative" in the mathematical sense of the term. ------------- PR Comment: https://git.openjdk.org/jdk/pull/14479#issuecomment-1610132362
