On Sat, Jan 10, 2015 at 06:56:45PM -0500, random...@fastmail.us wrote: > On Sat, Jan 10, 2015, at 16:47, Markus Wichmann wrote: > > You wanted to be Unicode compatible, right? Because in that case I > > expect [:alpha:] to be the class of all characters in General Category L > > (that is, Lu, Ll, Lt, Lm, or Lo). That includes a few more characters > > than just A-Z and a-z. And I don't see you add any other character to > > that class later. > > Note that translating between [:upper:] and [:lower:] requires using the > toupper and tolower mapping, rather than just dumping the character > classes (since otherwise you'll run into there being something like ß > that is in [:lower:] and has no counterpart in [:upper:], or they're in > a different order) >
Actually, ẞ, capital of ß, was added in Unicode 5.1. There are probably others letters with this issue, however.
