[rules-users] declared variables in rules loaded to the same knowledge base

[Salina Fung/UFL - ICIL]

Thanks for the explanation

So they are the same fact?


Thanks
Salina


----- Original Message -----
From: Wolfgang Laun
[mailto:wolfgang.laun at gmail.com]
To: salina at icil.net, Rules Users List
[mailto:rules-users at lists.jboss.org]
Sent: Thu, 09 Feb 2012 15:18:32
+0800
Subject: Re: [rules-users] declared variables in rules loaded to the
same knowledge base


> On 09/02/2012, Salina Fung/UFL - ICIL <salina at icil.net> wrote:
> > We have 2 rules - rule 1 and rule 2, both have
> > declared variable @role(event)
> 
> This is not a "variable" in the sense of the word as 99.99% use it.
> 
> The "declare EventImpl @role(event)...end tells Drools that
> facts of type EventImpl are facts with extended semantics,
> i.e., a timestamp and duration, and Fusion functions can
> be applied. Read the documentation!
> 
> 
> >
> > In the program with statements to define the rule
> >
> > <<
> > String rule1 = "package test001 import com.icil.event.*; declare EventImpl
> > @role(event) end rule \"test 001\" when Integer() then
> > System.out.println(\"rule test 001: there is an integer\"); end ";
> >
> > String rule2 = "package test002 import com.icil.event.*; declare EventImpl
> > @role(event) end rule \"test 002\" when Integer() then
> > System.out.println(\"rule test 002: there is an integer\"); end ";
> >>>
> >
> > and then  try to load these two into the same knowledge base using Drools
> > 5.3,
> > will get an runtime exception. But Drools 5.2, this is ok, with
> > no error.
> 
> I'm not trying to guess the exception.
> 
> >
> >
> > Then in Drools 5.2
> >
> > We try to print the address of the variable 'event' in the RHS of both
> > rules, the
> > address is the same in both rules, which means they are sharing the same
> > instance?
> 
> "event" is merely a word in the DRL text, recognized and discarded by
> the DRL parser. So I'd be *very* much surprised if you can obtain its
> "address" at runtime, in the RHS.
> 
> It's a pity that you don't show the code with which you print the "address"
> of something. In Java, that's quite an unusual thing to do.
> 
> Please don't report about things without showing them, in full.
> 
> -W
> 
> >
> > Is it the declared variables with the same name in separate
> > rules being loaded in the same knowledge base, will just
> > have ONE instance?
> >
> >
> >
> > Thanks
> > Salina
> >
> 
> >
>