Issue1878

Jython 2.5.2 is throwing this TypeError when met with a Java Map that is already itarable:

temp_id = Peer.tempid("db.part/user")
TypeError: Supertypes that share a modified attribute  have an MRO conflict[attribute=__iter__, types=[<type 'java.lang.Iterable'>, <type 'java.util.Map'>]]

Here's the Jython source that contains the error message:

  https://gist.github.com/2506332

See https://groups.google.com/d/msg/datomic/b8iODxDmmvM/soOcdhcvFmgJ

Thanks for the bug report James - your timing is good as we are closing in on a 2.5.3 and it would be very cool to see Datomic working with Jython.

I'm sure I'm just reading the bug report wrong - I tried

import java.util.HashMap;
import java.util.Iterator;

public class IterableMap extends HashMap implements Iterable {
    public Iterator iterator() {
        return this.keySet().iterator();
    }
}

But that doesn't trigger an MRO conflict - do you have a simple code snippet that triggers the problem?

Sure Frank -- here's a snippet that generates the error:

https://gist.github.com/2512943

Also notice the try/except hacks around Peer.tempid, conn.db, and Peer.q -- those are wrapped in a try/except block and then each method is immediately called again because it only generates an error the first time the method is called.

Hi James - thanks for the snippet - but I'm not currently a user of Datomic - is it possible for you to come up with a code snippet that doesn't have external dependencies - that will greatly help me get to the bottom of the bug.

Issue seen in another Clojure project, Storm. Should be readily resolvable by special casing in PyJavaType.

Potential fix in this branch:
https://bitbucket.org/jimbaker/proxies

Still needs decent test cases that do not depend on Storm/Clojure.

Fixed as of 7110:8d2f8c3a2299