Ideally, invalid states should be unrepresentable.
And clearly any language in which invalid states are representable is useless? Nice try, but nah. I like me some pure functions sometimes, but I'm not dogmatic about it.
Your response is so bad I almost think you're trolling... Hoping (I think) not:
"And clearly any language in which invalid states are representable is useless?"
I did not call anything useless, much less the entire language.
And I am the first to agree that trade-offs need to be made between a variety of considerations. But in this case, for the approach under discussion, I pointed out a design criteria that I find often important, that this approach is in flagrant violation of, while getting basically (perhaps literally) nothing in return toward any other design considerations.
Either I missed things or that's just a bad decision. If you think it's the former, please engage me more constructively so that at least one of us can learn something.
"Nice try, but nah."
This is needlessly rude.
"I like me some pure functions sometimes"
This issue has zero to do with pure functions.
"but I'm not dogmatic about it."
Right, pointing out bad design can only come from a place of dogma. Never experience, never consideration, and never anything that could permit substantive discussion.
And clearly any language in which invalid states are representable is useless? Nice try, but nah. I like me some pure functions sometimes, but I'm not dogmatic about it.