Eclipse - `open call hierarchy` stop searching in lambda chain

Question

Here is my sample java code:

public class Test {

    public static void main(String[] args) {
        methodDepth0(
            ()->
                methodDe         


        

Answer 1

As the second picture clearly shows, Eclipse is able to trace the call hierarchy through the method call myIf.call() inside methodDepth0. This is correct, because the (outer) lambda implements method MyIF.call().

The fact that the same pattern does not work in the next nesting level looks like a bug. Please consider filing a bug for JDT/UI. TIA.

Just note, that for lambdas implementing library types like Consumer<T>, the number of callers into accept(T) in a workspace may easily become unmanageable, similar to any call hierarchy through, e.g, Runnable.run() - but that doesn't question the general usefulness of call hierarchies through lambdas.

Answer 2

From what I can tell the lack of call hierarchy depth is due to (re)evaluation of code at runtime. It is explained in 15.27.4 Run-Time Evaluation of Lambda Expressions in the Java Language Specification.

At run time, evaluation of a lambda expression is similar to evaluation of a class instance creation expression, insofar as normal completion produces a reference to an object. Evaluation of a lambda expression is distinct from execution of the lambda body.