I meant the valueness check. I know their motivation has to do with type safety (IIRC, it's to avoid what we know in Haskell as unsafeCoerce-via-unsafePerformIO).

On Wed, Jan 25, 2023, 9:07 PM Richard Eisenberg <lists@richarde.dev> wrote:


On Jan 22, 2023, at 1:12 AM, David Feuer <david.feuer@gmail.com> wrote:

That's what ML calls the "value restriction", right?

No, ML's value restriction is unrelated to this conversation. ML's value restriction says that all polymorphic variables (top-level or otherwise) must syntactically be values -- not, say, function calls. The "value-ness" check might end up similar, but the motivations are distinct.

Richard