in reply to Are state machines just for parsing?

They are also used for application state and workflow processes. I don't normally formally create an FSA but I could draw out a diagram if pressed to do so.

As for your problem, couldn't you just serialize your DFA::Simple object's state to storage between web requests? I imagine it would take a bit of custom work because you won't be able to just Storable::freeze() the object - it contains code references. That's easy to work around - just store the name of the function it is supposed to call and when rebuilding your object, reassociate the hard reference. You might also just give DFA::Simple the ability to call functions by name and avoid having code references at all.

  • Comment on Re: Are state machines just for parsing?

Replies are listed 'Best First'.
Re^2: Are state machines just for parsing?
by samtregar (Abbot) on Dec 07, 2004 at 22:23 UTC
    As for your problem, couldn't you just serialize your DFA::Simple object's state to storage between web requests?

    That's not the problem. The problem is that DFA::Simple wants to parse text on a filehandle to trigger events. I don't have a text file full of events, I have a user on the other end of an HTTP connection!

    -sam

[reply]
      I didn't see anything in the referenced code to indicate that it parsed anything. All it does to decide the next state is run a bunch of your test functions to see which one returns true. What your test functions do is up to them.
[reply]
        You know, I think you're right. I didn't think hard enough about what $_ was in the examples I was looking at.

        Now I guess the only problem is that the code in DFA::Simple is decidedly scary. Maybe by tomorrow I'll have shaken the memory and I can start using the module with a clear conscience.

        Thanks!
        -sam

[reply]

In Section Seekers of Perl Wisdom