[ajross]

FWIW, I'm talking about the pattern matching syntax required to enforce coverage of all the sum types. Obviously the idea of the representation as a set of alternatives is easy enough to understand. The idea of "Now You Have To Show The Compiler You Know What To Do In All Circumstances" is very much not, c.f. how much basically everyone struggles with Option() in Rust.

Inheritance addresses similar issues by delegating the responsibility, something that is easy to understand. Does it have downsides? Sure. But I'm not sold that ADT has the advantage here at all.