Re: the ScriptingMojo

On 08/22/20 15:12, Kartik Ohri wrote:

> I really like this idea. But I am not sure how to work this out. The main
> point of contention is the class type of platforms["Linux"]. I tested with
> Nashorn and Graal and printed the class of the object in the constructor.
> For nashorn, it is jdk.nashorn.api.scripting.ScriptObjectMirror and for
> graal it is com.oracle.truffle.polyglot.PolyglotMap.

If I do the attached, it does what I was hoping for. The constructor prints

PGXS impl class is
jdk.nashorn.javaadapters.org_postgresql_pljava_pgxs_PGXSUtils$PGXS

in nashorn, or

PGXS impl class is org.postgresql.pljava.pgxs.PGXSUtils$PGXS$$JSJavaAdapter

in graal. (Wow, pretty sneaky, Graal fakes up a class that is even in
the superclass's package! I bet it's using MethodHandles.Lookup.defineClass,
which appeared in Java 9 so Nashorn probably doesn't.)

The new Foo(jsobject) syntax only has magic if Foo is an interface or an
abstract class. If Foo is an instantiable class, that will be parsed as
simply calling a one-argument constructor to instantiate it, and passing
the jsobject as the argument. Maybe that is what you were seeing?

You sort of have to believe with this stuff; ask too many questions and
you drive the magic away.

Regards,
-Chap