“My name is Bill Venners and today my goal is to compare functional error handling in Scalaz and Scalactic... without creating an explosion on the Scalaz mailing list!,” begins Bill playfully at his talk for NE Scala 2015.
Instead of summarizing his talk, in this case, I’ll let Bill do the talking, I think it best to simply share his abstract posted on the conference website:
In this talk I'll compare and contrast the approaches to functional error handling taken by Scalaz and Scalactic. I'll look at how different opinions on typeclass coherence led to two classes in Scalaz, \/ and Validation, and just one in Scalactic, Or. I'll explain why when it comes to success values, I feel left is right and right is wrong, whereas the Scalazzi think the opposite. I'll show how the libraries use algebraic structures differently. And I'll explore how different opinions on how best to leverage functional programming (FP) in Scala led to different library designs.