You're reinforcing my point. You're assuming imperative semantics. Wherever "destiny" would be appropriate, you necessarily have a referentially transparent fu

You're reinforcing my point. You're assuming imperative semantics. Wherever "destiny" would be appropriate, you necessarily have a referentially transparent function. Wherever you have a referentially transparent function, a smart compiler or runtime can avoid recalculating anyway, without bothering the programmer with the distinction between "function" and "destiny".