Sleep is good.

Apart from the usual reasons, I mean. I'm talking about the kind of sleep you have after you've been busily hacking away on several different projects for the last couple of days, when the code's just gone all bleary and every change you make fixes one problem but creates something even more peculiar. Eventually you realise that you're not only not making any headway, you're in fact either going backward or building an immense wall of Stuff That Makes No Sense, so you turn things off and go to bed at quarter to nine, and you sleep. Boy howdy, do you ever sleep. You sleep so hard that you're not sure whether you're dreaming the alarm clock, and you're tired when you wake up from just how hard you slept.

Then you get up and you do anything else: you read, go for a bike ride, make the cats dance around after the feather-on-a-string toy you bought them, or perhaps you do what I did, which was go to drill. Eventually you decide, "Okay, I'll take a look at that problem again," and then you realise, Oh. All the logic is good except for this typo here. And you fix it. And it works.

The upshot of this is that my XSLT bitwise operators are no longer having that really weird recursion error or the stack overflow that followed it. They Just Work(tm). Now it's time to find dinner and grok some more of Applied Cryptography and then put these building blocks to good use.