Open Session to consider the revision of the SI

[Werner Keil]

The 26th CGPM will decide over the revision of the SI today.

The session is available on YouTube now: https://youtu.be/qA67T7FPBME

[Werner Keil]

The revision of the SI was unanimously approved by the all voting member countries who attended the 26th CGPM.

[Werner Keil]

Hi,

As the SI redefinition was approved, it also has some relevance to our project plan for JSR 385.

The goal for the Final release had always been "Spring 2019" so that it can be used slightly before the new SI definitions take effect on May 20th.

We have a couple of "epics" primarily:

- Documentation: https://github.com/unitsofmeasurement/unit-api/labels/documentation / https://github.com/unitsofmeasurement/indriya/labels/documentation
This is where JavaDoc improvements and documenting e.g. the new SI definitions come into play.

- Enhancement: https://github.com/unitsofmeasurement/unit-api/labels/enhancement / https://github.com/unitsofmeasurement/indriya/labels/enhancement

- Format: https://github.com/unitsofmeasurement/unit-api/labels/format / https://github.com/unitsofmeasurement/indriya/labels/format
The main challenge here is CompoundFormat (systems like Mathematica/Wolfram call it MixedFormat) allowing to parse and format legal Unit combinations like "6 ft, 2 in" or similar.

- Function: https://github.com/unitsofmeasurement/unit-api/labels/function / https://github.com/unitsofmeasurement/indriya/labels/function
The major issue here is handling operations between certain units like Temperature more precisely. Without negative side-effect on all the other units and operations between them.

Documentation and as many Enhancements as possible should be included. Everything else depends on the progress and maturity.

If some epic is not ready, it may have to wait till a follow-up release. Either a MR of the JSR (much is on the implementation side, especially Compound Formatting) or a new version. Any major new version is potentially going to be iterative as per JSR 387 (this one started before 387, hence it cannot be iterative yet) so no worries, if something won't make it into the 2.0 release. Being ready by World Metrology Day 2019 is however important, unlike the JDK the SI standard doesn't release every 6 months ;-)

Regards,

Werner