[rules-users] About for and inheritance

[Evert Penninckx]

The problem is exactly that smell is not an attribute of Cheesy (for this
Cheese example we could argue if that makes sense, but in my context it 's
impossible). 

I thought I had an error from the drools plugin when using instanceof even
in eval, but I'll try that again, I think I tried eval(this instanceof ...).
In my case it would still mean writing something like

when
       $person : Person ()
       $cheese : Cheese( eval( $cheese instanceof FrenchCheese) ) from
$person.getLikes()
       FrenchCheese( smell == "good" ) from $cheese 

Overloading getLikes() would be more elegant. Still, for me these are
workarounds. 

Would it be that strange or unconventional to have the from only match on
the required subclass?

Grtz

Evert


Wolfgang Laun-2 wrote:
> 
> If smell is a property of Cheese and not just of FrenchCheese you could
> use
> 
> 
> when
>        $person : Person ()
>        $c: Cheese( eval( $c instanceof FrenchCheese), smell == "good" )
> from
> $person.getLikes()
> then
> 
> Also, I think that a selective retrieval with an overloaded version of
> getLikes():
>    getLikes( Class clazz )
> might be useful, avoiding useless elements in the returned collection.
> 
> -W
> 
> 
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