Haskell has much more powerful polymorphism as provided by typeclasses and various extensions like Multi-parameter typeclasses. Haskell, more than any other pro

Haskell has much more powerful polymorphism as provided by typeclasses and various extensions like Multi-parameter typeclasses. Haskell, more than any other production-ready language, is able to encapsulate the essence of "doing the same thing in a different context", which means you can easily write code that is reusable to a degree not imaginable in most languages. For example, the expression "fold", from Data.Foldable, is capable of doing anything from concatenating all the strings in a set to adding up all the probability distributions in a sequence. This is a contrived example, but it's super useful in practice. It's hard to imagine all the code reuse you can get, especially as a library author, without using Haskell for a while. The most obvious cases are Ord and Eq, where things like maps and sets can contain any orderable type, rather than just a few types like String and Int.