[pdkl95]

It's not really any surprise that templates (or CSS) could be Turing complete, as all the lambda() function does is the same thing a template does - replacing the macros in a template with an argument.

This is actually an important lesson that is often missed: if the app you're writing gives the anonymous users any kind of find/replace macro capability, you're giving them a fully Turing complete language (though it's probably not easy, but that rarely stops anyone) and all the potential problems that can bring.