On Fri, 27 Feb 2009, Bill Janssen wrote:
Andi Vajda <va...@apache.org> wrote:
I changed the 'Type' suffix used to name Python types to '$$Type'.
neo4j now lets itself be wrapped. Fixed in rev 748053.
Andi, thanks for this.
Though it brings up another matter :-).
neo4j has this funky RelationshipType usage, too. RelationshipType is
an interface, and you instantiate classes that implement that interface
to create distinct relationship types (thus the name). So I had to
write some Java code to allow me to write Python classes for this
purpose -- a Java Python-extension class which implements
RelationshipType. But the example on the neo4j page does it a bit
differently, using a Java enum:
enum MyRelationshipTypes implements RelationshipType
{
KNOWS,
FORGETS
}
This presumably creates a set of instances (KNOWS and FORGETS), each of
which is a MyRelationshipTypes. Is there any alternative mapping of
this kind of thing via JCC to the Python world?
At this point, JCC does not support any of the new language features
introduced in Java 1.5 such as generics. Unless I'm mistaken (Java 1.5 is
not so new anymore and I forget which is what), enums were also introduced
then.
Why not support these Java 1.5 features ? Well, JCC's needs were originally
driven by PyLucene's and until Java Lucene starts using Java 1.5 features, I
didn't feel it high priority to implement support for them.
Java Lucene is still not using Java 1.5 features. I believe this is slated
for release 3.0 which is still some way off.
Maybe it's time to add support for these features in JCC regardless. It's
been years...
This would also solve the problem you were having with the PythonSet
implementation earlier since being able to use it as PythonSet<String> would
help it work a lot better.
How do you workaround this with the current JCC features ? At this point, I
don't know what an enum is turned into from a Java reflection's perspective
but I seem to remember that all these Java 1.5 features were implemented in
terms of earlier (pre-Java 1.5) building blocks. This would seem to indicate
that your enums may be found as instances of some auto-generated class, for
example ?
To find out, add your custom Java code (with these enums) to your build and
see what gets generated for them. Maybe there is a way then to use them from
Python (don't forget to mark it public too, otherwise JCC is going to
ignore it anyway).
Andi..
