The last couple of years I've been doing a lot of exploring different languages and language features. Sum types are one of the few features I've come across t

The last couple of years I've been doing a lot of exploring different languages and language features. Sum types are one of the few features I've come across that seem to have the potential for large, practical benefit. Not only do you get the potential to eliminate null from a language with Option or Maybe types, but many cases where you might use multiple classes and files to express some hierarchy, can be replaced with just a few lines of code that is so easy to read you can even show it directly to the non programmers working on the project, to work through the definition together. This especially happens nicely when the syntax is built into the language in a succinct way as in F# / OCaml (possibly others as well!)