[mrtranscendence]

I haven't programmed in Java since 2005, so forgive me. But isn't a lambda automatically converted to an object of the necessary single-method type? That feels a little magical and suggests that there really isn't such a thing as a genuine first-class function in Java, as there is no way to define a function, and no universal type to assign to such a thing.

[kaba0]

Well, the standard library does have some function types, like Function<A,B>, Supplier<A>, etc. You can just initialize a variable of these types and pass them around. I don’t see how are these not genuine first-class entities. The lambda syntax is also quite pleasant.

(Also, behind the scenes they often compile to static functions and called through the invokedynamic instruction)