I have a lot of code that has been using Java reflection to invoke arbitrary user-specified methods on Java objects, as part of a DSL.
However, a lot of those Java objects, in practice, are Scala objects, and some of the methods on them are marked with the Scala @deprecated
annotation. Unfortunately, Java's annotations mechanism cannot see Scala annotations, and until Scala 2.10 there was no convenient way (that I know of?) to get access to those annotations.
I have finally upgraded to 2.10, and would like to be able to emit deprecation warnings from my DSL. However, I don't want to rewrite the entire evaluator (for now, at least) to use Scala reflection, so is there a convenient way to go from a java.lang.reflect.Method
to something I can use Scala reflection on to figure out if the Scala method in question is deprecated? Or will I have to duplicate a lot of the existing method resolution logic using Scala reflection before I can get at that information?
It looks like a JavaToScala
class used to exist in Scala reflection, which had a methodToScala
method in it that did what I want. The only trace I can find is here, in a google code project. Why was the functionality moved out of core reflection? Or is it still there under a different name?
Edit: It looks like the code in question lives on in scala.reflect.runtime.JavaMirrors
, but unfortunately it's private (there's another JavaMirrors
that is part of the public API, but doesn't provide any of what I need.) I can't figure out for the life of me if there's a "path" of invocations through a public API that takes me all the way down to the private methodAsScala
buried deep within the private JavaMirrors
. It's frustrating, to say the least :(