That bigotimes function that it's talking about is doing something like tree search with backtracking - lazy evaluation isn't really relevant as far as I can see. I don't think the statement that it's "one pass" is meant to mean that it's a closed form solution or something, the point is that you can write your code as plain single pass logic and this generic functional tool does the rest.
It's a showcase for Haskell and well worth reading. I should be less snide.
Nowadays "multipass" means Mila Jovovich but it used to mean "another complex language with massive implications we deal with by divide-and-conquer-through-the-filesystem" and in the case of the York ada compiler that was some amazing number like 10 or more passes.
There was a fashion for running your C instrumented and then recompiling it after runtime branch choice evidence was collected. I think the Dec Alpha OSF/1 compiler did it optionally.
> There was a fashion for running your C instrumented and then recompiling it after runtime branch choice evidence was collected. I think the Dec Alpha OSF/1 compiler did it optionally.
This is called profile-guided optimization and new compilers (well, GCC and LLVM) have it.
I mostly think it's bad and not statistically sound; given profile data the compiler is both overly trusting of it (no error bars) and can't find much useful to do with it (because there's no way to hint a modern OoO CPU).
