[e-lang] E / Python interoperability suggestions?

[Thomas Leonard]

What are the current thoughts on interoperability between E (captp) and
other languages / protocols?

We had to integrate our system with a BPEL engine running on Apache
ServiceMix recently, and that was easy enough because it's all Java, so
we just put e.jar into ServiceMix and let it accept captp connections.

But now we want to integrate with a service being developed in Python
(Django). The development has only just started, so we've got some
flexibility but I'm wondering what the best approach is. Ideally, we'd
like an approach that makes it easier to integrate with other languages
in future.

One option would be to implement captp / Pluribus in Python. It sounds
like this might be difficult:

  http://www.eros-os.org/pipermail/cap-talk/2007-February/007540.html

There was also some interest from a Twisted Python developer:

  http://www.eros-os.org/pipermail/e-lang/2005-April/010565.html

MarkM said:

        "Another option you should seriously consider is implementing
        the web-calculus before-or-instead-of implementing CapTP.
        CapTP/Data-E isn't really designed to be a good standard for
        interoperation between cap systems, whereas the web-calculus is.
        I expect and hope to see a web-calculus comm system in E for E
        eventually. CapTP will continue to be E's default, since it more
        transparently extends E's local semantics, but the web-calculus
        is a better way for E to interoperate with other cap systems."

There seem to be other "captp-inspired" protocols - such as
http://code.google.com/p/caja-captp/ - but it's not clear whether this
actually interoperates with E.

About captp, MarkM said:
        
        "There are four protocol transitions CapTP needs to make. Given
        the
        current minuscule adoption, I'm inclined to make all four changes
        simultaneously and not worry about compatibility.
        
        * Switching from our custom DataComm to a VatTP layered on top of TLS.
        Tyler and Kevin have both made progress towards this goal.
        * Switching from Java serialization, as used by E-on-Java, to Data-E,
        as used by E-on-CommonLisp and Caja-CapTP.
        * Dropping the SwissHash from the live reference protocol as discussed
        in this thread.
        * Change the exposed object APIs (esp the Miranda Methods) to
        something more language neutral, as already adopted by Caja-CapTP, so
        that Caja-CapTP and E-CapTP can interoperate better."

  http://www.eros-os.org/pipermail/e-lang/2009-September/013256.html

Has any progress been made with any of these plans? What's the current
thinking?

Thanks,


-- 
Dr Thomas Leonard
IT Innovation Centre
2 Venture Road
Southampton
Hampshire SO16 7NP

Tel: +44 0 23 8076 0834
Fax: +44 0 23 8076 0833
mailto:tal at it-innovation.soton.ac.uk
http://www.it-innovation.soton.ac.uk