Replying so that this message is reflected in the SG16 list archives due to an archive failure following the transition to the new SG16 mailing list.

Tom.

On 11/23/19 9:02 PM, Victor Zverovich via SG16 wrote:
Dear Unicoders,

Per Zach's suggestion I'm writing to clarify the origin of the width estimate table in P1868.

The table is based on Markus Kuhn's open-source implementation of `wcwidth()` and `wcswidth()` for Unicode (https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c) which is listed in the references. We translated it from code into a table form.

There are other implementations of display width estimation, some of which were overfit to particular terminals. The one by Kuhn was simple enough and gave reasonable results in tests which is why we used it.

Cheers,
Victor