Subject: Re: the ScriptingMojo
To: Kartik Ohri <kartikohri13@gmail.com>
References: 
 <CAASLQ4Mva7dAXiS_c9OLhV4VzNHF=XNKJosuS5gtZTB6b4TW1Q@mail.gmail.com>
 <5F2EC4F4.3080608@anastigmatix.net>
 <CAASLQ4M3pR+ZL+uPvcQ-dAEL2KdH_PGe-_pBhsjvOgN5qvf+aA@mail.gmail.com>
 <5F31EFEC.1080609@anastigmatix.net>
 <CAASLQ4NU9v=nuLDG-LneC68LuqKRXchFckU7mCZT9YQDNKqwvg@mail.gmail.com>
 <5F368380.9070203@anastigmatix.net>
 <CAASLQ4NgH+tXbdUSA8xDh2ct3gAS3xa8V7=E0gcYd+d=m8kujw@mail.gmail.com>
 <5F368A99.6070709@anastigmatix.net> <5F36965C.60707@anastigmatix.net>
 <5F3A7DC6.8090905@anastigmatix.net>
 <CAASLQ4PEgo5Nj0EVsOfGoB96dQFXfFYxrrB0rS1wdad7x_E5fA@mail.gmail.com>
 <CAASLQ4OowXOmnbbbT0Wh1ZkB4h=6JQfC61ojmN07EYnO0QCcow@mail.gmail.com>
 <5F3D32E9.80504@anastigmatix.net> <5F3D36BE.70703@anastigmatix.net>
 <5F3D38F8.7050907@anastigmatix.net> <5F3D3A75.5010304@anastigmatix.net>
 <5F3D3D2E.4070109@anastigmatix.net> <5F3D43BD.4020900@anastigmatix.net>
 <5F3DA48D.7090408@anastigmatix.net>
 <CAASLQ4MBWQeFLdAPNcsgcpLyekU5X=ExQUuGgE49AUFdEYJr8g@mail.gmail.com>
Cc: pljava-dev@lists.postgresql.org
From: Chapman Flack <chap@anastigmatix.net>
Message-ID: <5F41943D.9080707@anastigmatix.net>
Date: Sat, 22 Aug 2020 17:55:09 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.7.0
MIME-Version: 1.0
In-Reply-To: 
 <CAASLQ4MBWQeFLdAPNcsgcpLyekU5X=ExQUuGgE49AUFdEYJr8g@mail.gmail.com>
Content-Type: multipart/mixed;
 boundary="------------070509090807050104040202"
Precedence: bulk

This is a multi-part message in MIME format.
--------------070509090807050104040202
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

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

--------------070509090807050104040202
Content-Type: image/x-coreldrawpattern;
 name="pgxs.pat"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="pgxs.pat"
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==
--------------070509090807050104040202--