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)
