Comment by Someone

Yes, you could, but chances are that the provable upper bounds on memory usage or execution time are orders of magnitude above what you think it should take. Anything that produces a new value where you cannot prove that another value becomes unreachable (in which case the compiler could translate it to a destructive update) could trigger a garbage collection that might write half a GB of memory and takes .1 of a second (numbers may be realistic, but if they are, it's pure luck)