Note that I'm not suggesting Haskell should do anything like this. I'm playing around with the ideas because I'm interesting in creating a lazy language and I was hoping to have strictness analysis be very predictable and uniform, something the programmer can count on and use to simply reason about space usage ... which might be hopelessly unrealistic goal!

Others have commented on the undecidability of your problem. I can't come up with a reasonable definition of "perfect" which is decidable (but that may be due to lack of imagination on my part).

However, there is nothing undecidable about your larger goal of creating a lazy language with easy space reasoning. I wholeheartedly support this effort, and hope you will continue to blog about your ideas in this area.

Luke