[rules-users] Rules to detect states in an object graph?!?

[Anstis, Michael (M.)]

Thanks Steve,
 
Is contains in 3.0.5 - I can't find reference to it in the bundled
documentation?
 
Also, do you know whether Object's equals() and Object's hashCode() are
used for normal equality conditions:-
 
when
    h : house()
    p : person ( residence == ( h ) )
...
 
Do you also know how the greater than and less than operators are
implemented (can we provide a comparator instance)?
 
when
    r : rank()
    p : person (rank >= ( r ) )
...
 
(If this is even possible!?!? - I haven't got this far yet).
 
Thanks in advance.
 
Mike
 


________________________________

	From: rules-users-bounces at lists.jboss.org
[mailto:rules-users-bounces at lists.jboss.org] On Behalf Of Steven
Williams
	Sent: 23 January 2007 23:00
	To: Rules Users List
	Subject: Re: [rules-users] Rules to detect states in an object
graph?!?
	
	
	Hi Michael,
	
	To do the opposite approach (where the relationship is navigable
from the parent only) you can use the following:
	
	when
	        c : Child ( age > 18 ) 
	        Parent ( children contains c, type == "SMURF" ) 
	
	Of course this requires either 
	

	*	the child object in the children collection to be the
same as the asserted child object or 
		
	*	the equals/hashcode method to be implemented
appropriately in Child 
		

	cheers
	Steve
	
	
	On 1/24/07, Anstis, Michael (M.) <manstis1 at ford.com> wrote: 

		Sorry, me again, 

		I'm putting together some prototype rules that operate
on related objects in a graph of objects. 

		I'm adding all objects individually to working memory
and then checking the objects are related in the rule to ensure only
valid combinations are selected; for example:-

		//Java code 
		parent.addChild(child) 
		wm.assertObject(parent); 
		wm.assertObject(child); 

		//Rule 
		rule "Adult smurfs" 
		when 
		        c : Child ( age > 18, p : parent ) 
		        Parent ( parentId == ( p.parentId ) , type ==
"SMURF" ) 
		then 
		        System.out.println("Smurf " + p.getName() + " is
" + c.getAge() + " years old." 
		end 

		rule "Adult clangers" 
		when 
		        c : Child ( age > 18, p : parent ) 
		        Parent ( parentId == ( p.parentId ) , type ==
"CLANGER" ) 
		then 
		        System.out.println("Clanger " + p.getName() + "
is " + c.getAge() + " years old." 
		end 

		This requires that the parent-child relationship is
navigable from the child end of the relationship -- child.getParent() .

		What other approaches does anyone else use to implement
rules that span related objects? 

		With kind regards, 

		Michael Anstis
		-------------------------------------------
		Next Generation Estimating System 
		* Trafford House (Int) 8 718 2239 
		* Trafford House (Ext) +44 (0)1268 702239 
		* < mailto:manstis1 at ford.com <mailto:manstis1 at ford.com>
> 


		_______________________________________________
		rules-users mailing list
		rules-users at lists.jboss.org
		https://lists.jboss.org/mailman/listinfo/rules-users
		
		
		




	-- 
	Steven Williams
	
	Supervising Consultant
	
	Object Consulting
	Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501 
	stevenw at objectconsulting.com.au
	www.objectconsulting.com.au
	
	consulting | development | training | support 
	our experience makes the difference 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20070124/ff3ca491/attachment.html