On May 30, 2007, at 13:40, Jordan Coleman wrote:
On May 30, 2007, at 8:15 AM, Kidney Bingos wrote:
So, dear fellow POEvangelists, I am now on the hunt for possible
things that
can be hacked on.
I may be the only one interested in this, but I'd love to see
something that gives POE a simple paradigm for message passing and
dispatching between sessions, similar to Uri Guttman's Stem framework.
I'm not terribly familiar with Stem myself, but from what I've
gleaned, one of its big features is you can very easily create a
session (a "cell" in Stem lingo) that accepts an incoming message
by declaring within that session a sub named with a certain
convention. Stem has some underlying registration and dispatching
so that you can plug cells together into an application and set up
the message mapping between them. It's a very slick convention,
very much in the style of Catalyst's controller actions.
Again, I'm far from an expert on Stem, so someone else may need to
clarify (or dismiss) what I'm talking about here, but I just can't
help but think about the value of having Stem's message passing
concept combined with all of POE's capabilities and library of
components, wheels, etc.
This sounds a lot like POE::Stage. See CPAN, where a developer alpha
has been lurking for a while. It's a formal version of POE's
stronger design patterns, and it's my personal vision for POE's
future. It's most fundamental ideas are:
1. Request and response messages are like asynchronous method calls
and returns. There is a request tree rather than a call stack.
2. Messages have associated variable scopes. This is a side effect
of requests behaving like method calls. These scopes may persist
over the course of many calls, as long as the message is still active.
3. Responses are typed, and the caller maps response types to
callbacks. This is done within requests rather than at the Session
level. Stages are more loosely coupled than components or sessions.
4. There is lexical magic inherent in the naming of things. A lot of
this is derived from discussions with Catalyst people in irc.perl.org
#poe (hi, Matt). Also see Lexical::Persistence, which was released
as an offshoot of POE::Stage.
Sample code? Here's a working "Hello, World" from the synopsis:
http://thirdlobe.com/projects/poe-stage/browser/trunk/examples/poe-
stage-synopsis.perl
Other, more involved examples are in the same directory. This one
illustrates many of the fundamental ideas:
http://thirdlobe.com/projects/poe-stage/browser/trunk/examples/
01_basics.perl
If the hackathon's going to tackle this, there are two main things to
be done. They're widely-scoped, but they can be dealt with in pieces:
1. Flesh out the basics. POE::Stage should do at least as much as
POE's basic wheels and components. Things that rely on optional
dependencies (Tk, Curses, etc.) aren't necessary.
2. The paradigm may be flawed, especially around the edge cases.
Identify and catalog the issues. If possible, and time permitting,
fix them.
I think this is a highly worthy project, and I suspect that not
enough people know about it.
I'll be happy to answer questions about the project. Please direct
them to the list.
Anyone who wants to work on the project (hackathon or not) should
send private e-mail with a user name and password, generated by
running htpasswd -ns $username. I'll set you up with repository access.
Thanks!
--
Rocco Caputo - [EMAIL PROTECTED]
