The five properties used as headings in the article are able to be expressed in good type systems. This way a huge part of the specification becomes code, and t

The five properties used as headings in the article are able to be expressed in good type systems. This way a huge part of the specification becomes code, and the compiler guarantees to uphold the expressed properties in many or all cases. We should strive to have a programming future where this idea is normal and commonplace. OpenAPI and GraphQL have exceedingly poor types, and will not bring us there unless they make a fifty year leap forward.