Sure, but there are many kinds of interpreters! I was involved with one that wasn't really demanding in terms of computation, but was distributed in a way that

Sure, but there are many kinds of interpreters! I was involved with one that wasn't really demanding in terms of computation, but was distributed in a way that required a lot of speculation and rollbacks. The functional approach was pretty sweet. Highest speed bytecode interpreter is actually one of the few loops where I prefer assembly to C, as the instruction mix, branch prediction and even the use of stack can be weird from the PoV of a modern optimizing compiler.