I prefer languages that allow you to build abstractions like this, rather than being beholden to the standards body. I use Either types in javascript. I coded

I prefer languages that allow you to build abstractions like this, rather than being beholden to the standards body. I use Either types in javascript. I coded them myself (I like mine better than those in the article, but I would wouldn't I?). I check it all with typescript, and it's perfectly typesafe, same as it would be in haskell or ocaml. So Javascript is 100% a language that allows you to build abstractions like that.