On Wed, 3 Mar 2021 07:20:03 GMT, Joe Darcy <da...@openjdk.org> wrote:
> I considered @stuart-marks previous suggestion during the code review of > JDK-8261123 to include a more explicit discussion of why, say, different > representations of 2 should not be regarded as equivalent. After > contemplating several alternatives, I didn't find anything simpler than > Stuart's 2/3 example so I used that as seen in the diff. > > A short digression, BigDecimal supports both fixed-point style and > floating-point style rounding. Floating-point rounding primarily replies on > the number of precision digits, regards of their scale, while fixed-point > style rounding prioritizes the scale. The number of digits of eventual output > is a function of number number of digits in the inputs and the number of > precision digits in a floating-point style rounding. A floating-point style > rounding has a preferred scale, rather than a fixed scale based on the > inputs. The fixed-point style divide method used in the example has a scale > based on the dividend, allowing a relatively simple expression to show a > distinction between 2.0 and 2.00. src/java.base/share/classes/java/math/BigDecimal.java line 3146: > 3144: * method since the former has [{@code BigInteger}, > 3145: * {@code scale}] components equal to [20, 1] while the latter has > 3146: * components equals to [200, 2]. s/equals/equal/ ------------- PR: https://git.openjdk.java.net/jdk/pull/2804