Lambdas in the classical Operation enum example

Question

As many of you may know, there is a classical example of the Operation enum (using Java 8 standard interface now though), that is the following:

Answer 1

It depends how you define better.

In your case and in my opinion, the lambdas are a pure win. You can even reuse some existing JDK functions, e.g.:

enum Operation implements DoubleBinaryOperator {
    PLUS    ("+", Double::sum),
    ...
}

This is short and readable. I don't think anything reasonable can be said about performance w/o benchmarking your code.

Lambdas are implemented with invokeDynamic to dynamically link call site to actual code to execute; no anonymous, inner classes.