If someone is wondering about the relationship between sum types (discriminated unions / case classes) and the visitor pattern, I've written about this here [1]

If someone is wondering about the relationship between sum types (discriminated unions / case classes) and the visitor pattern, I've written about this here [1]. [1] http://paulkoerbitz.de/posts/Sum-Types-Visitors-and-the-Expression-Problem.html http://paulkoerbitz.de/posts/Sum-Types-Visitors-and-the-Expr...