> that doesn't throw if the email is invalid

Why can't it 'throw' if the email is invalid? You can — and would — encode that into the contract, detailing exactly what that means, so no problem for the user. They will write their code expecting that condition and everything will be fine. There is nothing special about failure cases. It is only a state, just like every other state.

> At this point, it's fairly clear that you are just thoroughly confused about how any of this works and what is actually possible.

Ad hominem is a logical fallacy. It is surprising that a comment that claims to understand programming language types in great detail would also commit an obvious logical error, given how important logic is in that context. But, stranger things have happened, I suppose. Unfortunately, there is nothing we can take from a logical error. Assuming it was trying to be written in good faith and free of errors, no doubt we'll get a meaningful explanation of what was actually trying to be expressed with code examples to follow. Looking forward to it.

Thank you for (once again) making it clear to any reader that you are not to be taken seriously. If only we could edit older comments so that the reader didn't have to suffer through all your nonsense to find out.