Why can't we merge Missing and Nothing?

[HFriberg-mosek]

@HFriberg-mosek

My (perhaps naive) take on it was that perhaps it should not be the type, but the way you use it, that determines whether it behaved as Nothing or Missing. Just like you have skipmissing to tell how Missing should be treated.

Nahh, scratch that. I would rather have the caller actively choosing whether something should behave like Nothing or Missing. Transferring this choice of interpretation to the callee sounds like trouble. The type is a contract.