higher-kinded-types - w3toppers.com

Using context bounds “negatively” to ensure type class instance is absent from scope

I eventually solved this using an ambiguity-based solution that doesn’t require prioritizing using inheritance. Here is my attempt at generalizing this. We use the type Not[A] to construct negative type classes: import scala.language.higherKinds trait Not[A] trait Monoid[_] // or import scalaz._, Scalaz._ type NotMonoid[A] = Not[Monoid[A]] trait Functor[_[_]] // or import scalaz._, Scalaz._ type NotFunctor[M[_]] … Read more

Higher-kinded generics in Java

I think what you’re trying to do is simply not supported by Java generics. The simpler case of public class Foo<T> { public T<String> bar() { return null; } } also does not compile using javac. Since Java does not know at compile-time what T is, it can’t guarantee that T<String> is at all meaningful. … Read more

What is a higher kinded type in Scala?

Let me make up for starting some of this confusion by pitching in with some disambiguation. I like to use the analogy to the value level to explain this, as people tend to be more familiar with it. A type constructor is a type that you can apply to type arguments to “construct” a type. … Read more