Tcl Meetup, 2022-03-09

In attendance: [B. C. Harder%|%Brad Harder], [Brian Griffin], [dgp%|%dgp], [Harald Oehlmann], [Hypnotoad], [Jan Nijtmans], [PYK%|%Poor Yorick], [D. Richard Hipp%|%Richard Hipp], [Schelte Bron], [Steve Huntley], [Andreas Kupries], [Rolf Ade], and others.

** Unicode **

Summary of surrogate pair issue:  8.6 always had issues handling them.  That handling changed around 8.6.10 (?) to be like 8.7. [string length] of certain Unicode scalar values is 2, as documented in TIP 542. [string length] of any single Unicode code point will be 1 in 9.0.
Jan Nijtmans suggested releasing 8.7 and 9.0 at the same time

Jan and ?? discussed Tcl_UniCharToUtf, which maintains some state information
about the string in the output buffer so that when it encounters a surrogate
pair, it can wait to output a character until it encounters the second half of the
pair, even though it only takes one character as an argument each time it is called.

Tcl_UniCharToUtf is used throughout the C sources, so teasing the ad-hoc utf-16
encode/decoder from Tcl will be a chore.

Brian mentioned that 8.7 crashed when he pasted an emoji into a text widget.