How to convert a DynamicConstantDesc to a MethodHandle?

[Steven Stewart-Gallus]

Hello,

I've stumbled upon a puzzler while writing a compiler from System F embedded in Java to methodhandles.

Given a DynamicConstantDesc how do I convert it to a MethodHandle that lazily loads the value alike ldc ?

It seems absurd spin an entire class for this.

I could create a MutableCallSite or perhaps a SwitchPoint for this but I don't really understand which would be better.

A regularly old object that does lazy initialisation with a flag would probably be fine but I feel like I should be able to do better.

I think I might be able to abuse the jit's handling of private finals in lambda objects to do this but I'm not quite certain that would work.

Thanks

Steven Stewart-Gallus

[Steven Stewart-Gallus]

I think basically I want the following API, but ideally thread safe and optimizable like a real LDC.

public final class LazyConstant {
    private ConstantDesc desc;
    private Object result;


    public LazyConstant(ConstantDesc desc) {
        this.desc = desc;
    }


    public Object resolve(MethodHandles.Lookup lookup) throws ReflectiveOperationException {
        if (null == result) {
            result = desc.resolveConstantDesc(lookup);
        }
        return result;
    }
}