I like the idea of 'G' to filter hunks. The perl script does not exist since git v2.40.0 so I don't think the installation instructions work for recent versions of git as there is no way to stop 'git add -p' from running the builtin version. I see this is MIT licenced but the code is very closely based on the perl script which is licensed under the GPLv2.
huh. I guess this is a prototype for features that will have be submitted to the upstream version. There was a feature in development for something like `git add -G <regex>`, maybe a decade ago, that never got completed.
As for licensing, I'm happy to change the license. I have no strong feelings on the subject, and don't know what restrictions GPLv2 imposes on a port to another language.