search
a = [#singleton]
b = [#singleton]
a != b
commit @error
[#error #description: "Multiple values for singleton!"]
I'm sure that's not the actual pattern you'll be using. My point is only that Eve provides a solid low-level foundation to implement higher-level patterns like a single-value type.
"My point is only that Eve provides a solid low-level foundation to implement higher-level patterns like a single-value type."
That's the problem. As long as single-value type is a higher level abstraction you are going in the opposite direction from "programming for everyone".