For me, I think the answer to this is really that Haskell is pure and immutable. Equational reasoning[1] is immensely useful when debugging. It isn't unusual t

For me, I think the answer to this is really that Haskell is pure and immutable. Equational reasoning[1] is immensely useful when debugging. It isn't unusual to debug pieces of Java code that look like this. MyClass c = new MyClass(..); c.method1(..); c.method2(..); c.method3(..); assert(c.someField == ..) // fails! To figure what went wrong, you have to read through all three methods and depending on whether you have dynamic dispatch coming into play, you might need to read through _multiple_ versions of all three methods. [1]: http://www.haskellforall.com/2013/12/equational-reasoning.html http://www.haskellforall.com/2013/12/equational-reasoning.ht...