Wow. That's just short-sighted. Left-handers comprise between 5% and 30% of the potential customer base. More if you consider that there are far fewer models of mice suitable for left-handed use available.
Someone should do a left handed mouse review blog or YouTube channel and just reject 95% of mice for being stupid. Sadly symmetrical is almost always the best you can hope for.
Tail recursion is a special case of tail calls that can be turned into loops. Their keyword is called tailrec, so it's probably not real TCO. Real tail call optimization can't easily be turned into loops in the general case.
Right now it seems to show an SHA1 hash encoded in hex, which is very inconvenient because ssh-keygen displays either MD5 in hex or SHA256 in base64. It should at least tell the user what hash algo was used, I found that out by trial and error.
