If what you're after is determinism, then your solution doesn't offer it. Both the formal specification and the code generated from it would be different each time. Formal specifications are useful when they're succinct, which is possible when they specify at a higher level of abstraction than code, which admits many different implemementations.

The point would presumably be to formalise it, then verify that the formal version matches what you actually meant. At which point you can't/shouldn't regenerate it, but you can request changes (which you'd need to verify and approve).