This is basically the expression problem: https://en.wikipedia.org/wiki/Expression_problem https://en.wikipedia.org/wiki/Expression_problem The expression prob

This is basically the expression problem: https://en.wikipedia.org/wiki/Expression_problem https://en.wikipedia.org/wiki/Expression_problem The expression problem is motivated by the fact that the OO style (which Go favors via interfaces) makes adding new cases easy (just add another subclass) but adding new methods hard (you have to modify every subclass), while the pattern matching style makes adding new methods easy (just add another match statement) but adding new cases hard (you potentially have to modify every match statement in the program). Depending on the task at hand, either one may be more advantageous. The solutions to the expression problem are attempts to get the best of both worlds. A lot of programming language designs deny that this is a tradeoff, which I think is misguided. Sometimes it's more convenient to be able to add methods easily, and sometimes it's more convenient to be able to add cases easily.