Re:Preserves: An Expressive Data Language
by choeger on Friday August 09, 2019 @04:09AM
(#20652225)
I applaude the author to think about sum types in the data language but the semantics part is slightly confusing. First it tells me that all records are equivalent and later it tells me how they are compared against each other. I think there should be a distinction between the form and their content being equivalent.
[ Parent
| on HN ]
Thanks for the feedback. However, I don't understand quite what you're getting at. Can you point out the wording you find confusing? I don't see anywhere that it says all records are equivalent.
Re: distinction between form and content, that's the intended aim of having separate "semantics" and (two) "syntax" sections. The idea is that to compare Values (i.e. to know which Value you have!), you work in terms of the "semantics" section, not in terms of any particular surface syntax.
You write
> Equivalence. Two Values are equal if neither is less than the other according to the total order.
Directly below the total order of what you call "kinds". That confused me.