From: Anders Bengtsson <ndrsbngtssn@...>
Date: 2003-06-11T04:12:41+09:00
Subject: Re: Iterators within Madeleine

Squidster wrote:
> I'm currently stumped in how to implement iterators within the
> confines on a Madeleine environment. It's very easy to just expose the
> entire instance with all its variables; but I want to build an "each"
> to be run via the "execute_command" method in Madeleine. Is this
> possible?

Hi Squidster,

I'm not sure if it's directly possible, but there should be some way of
working around it. Distributed Ruby itself (which the dictionary example
below uses) has a lot of code dealing with iterators, and still has some
limitations on them. (Not to mention the bad performance you get by
calling a remote object lots of times). But maybe you can get some ideas
from studying that code anyway.

> A scenario using the dictionary server sample program would be:
> To access the key/value pairs iterative via "each" within the confines
> of full concurrency protection.
> 
> Therefore, at the client, I should be able to do:
> 
>   dictionary.each { |key,val|
>     print "key=#{key}, val=#{val}\n" # read access
>     dictionary[key] = val + "foobar" # write access
>   }

Had this been on the server it wouldn't be a problem, you could just
wrap the entire snippet of code in a command object and it would be
done. I think the easiest way is just to do the entire operation of the
server and provide a wrapper method that the clients use.

> On top of that I should be able to do the above with multiple clients.
> 
> Is the above feasible or am I dreaming??... :-}

Don't know if I was to any help, but I like the thought that someone
would be dreaming about my code. :-)

/Anders

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A n d e r s  B e n g t s s o n  |  ndrsbngtssn@yahoo.se
Stockholm, Sweden               |