Thanks, I was struggling on this one :)

There is a strange requirement: "true123 is an identifier, as opposed to boolean followed by integer".. Looks like foreign for this task. Actually I ignored it (did not check and maintain this case). And my solvation passed all tests! May be you should remove this requirement from kata description?

Oh, you are right.

... yielding Token items until there are no more items to yield, at which point it should do whatever the appropriate action is for your chosen language.

I don't know Java, but a quick search reveals that next() should throw an exception when there's nothing more to return. Since this is the official spec of the interface, I'd say it's rather more obvious than not.

To pass "testException" in Java you have to throw an exception in "next()" if the string is empty, which is not obvious. Returning null or new Token(null, null) in "next()" or false in "hasNext()" doesn't work.

Description says that legs are "abcdefghijklmnopqrstuvwxyz", when they can also be in the upper case.

What the hell

Great kata, I like it!