And in Go since there is no parametric polymorphism you would end up writing either:

1) Methods with names that indicate the parameter types. 2) Method calls on objects to convert some internal struct data from one type to another. 3) Something I haven't thought of that doesn't involve losing a handle on your type.

So there is certainly a loss in convenience, but if you use the type system it can be just as safe as a functional language as far as I can tell. So, yeah, it isn't as intellectually elegant, but it also isn't really that hard to deal with.