[rules-users] Drools 4.0 StateExampleWithDynamicRules Question

[Daren Chylinski]

Hello,

 

I was pulled away from my Drools learning and now I am back.  I must
have missed the response to my previous inquiry.  Is there anyone that
has experienced the scenario described below?

 

Regards,

Daren

 

________________________________

From: rules-users-bounces at lists.jboss.org
[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Daren
Chylinski
Sent: Thursday, August 02, 2007 11:22 AM
To: rules-users at lists.jboss.org
Subject: [rules-users] Drools 4.0 StateExampleWithDynamicRules Question

 

Hello,

 

I am a new Drools user working my way through the examples.  To test my
understanding of how the rules work, I modified the
StateExampleUsingSalience.drl file used in the
StateExampleWithDynamicRules example.  The result of my change
conflicted with my understanding of how the rules should work.

 

I made two modifications in the StateExampleUsingSalience.drl file.  The
two modifications (shown below) are the commenting out of the two lines
in the RHS portion of the "B to D" rule.  My understanding of how this
would affect the result was:  because the "D" State object never changes
state to "State.FINISHED" the RHS portion of the "D to E" rule (shown
below) would not execute because the first pattern in the LHS would fail
to find a State object in working memory that met the criteria of the
constraint groups defined within it.

 

My question is:  Why does the "D to E" rule in the
StateExampleDynamicRules.drl execute the statements in the RHS portion
of the rule?

 

>From StateExampleUsingSalience.drl:  My changes in this file are the two
lines commented out in the RHS portion.

 

rule "B to D"

      when

            State(name == "B", state == State.FINISHED )                

            d : State(name == "D", state == State.NOTRUN )

      then

            //System.out.println(d.getName() + " finished" );

            //d.setState( State.FINISHED );

end

 

 

>From StateExampleDynamicRules.drl:  This is the rule where I expected
the RHS portion to NOT get executed because there aren't any State
objects in working memory that have their name == "D" and its state ==
State.FINISHED because the setState( State.FINISHED ) was never executed
on the "D" state object.

 

rule "D to E"

      when

            State(name == "D", state == State.FINISHED )                

            e : State(name == "E", state == State.NOTRUN )

      then

            System.out.println(e.getName() + " finished" );

            e.setState( State.FINISHED );

end

 

After my modifications, the output was:

 

A finished

B finished

C finished

E finished

 

I did not expect the "E finished" message to be printed.

 

 

Regards,

Daren



Confidentiality Notice: This e-mail message (including any attached or
embedded documents) is intended for the exclusive and confidential use of the
individual or entity to which this message is addressed, and unless otherwise
expressly indicated, is confidential and privileged information of Rackspace
Managed Hosting. Any dissemination, distribution or copying of the enclosed
material is prohibited. If you receive this transmission in error, please
notify us immediately by e-mail at abuse at rackspace.com, and delete the
original message. Your cooperation is appreciated.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20071003/0aae91f7/attachment.html