[rules-users] Fact Execution Order

[Nawrocki, Dan (IS)]

I want to control the order of firing for facts that match a single
rule.  I'm using Drools 5.0.1.  Is there any way to do this?

My problem can be boiled down as follows.  I have an array structure
that I want to conditionally copy to a new array structure.  I would
like to order of the destination array to match the source array.  The
code to insert facts into working memory increments in ascending order.
It is equivalent to:

for( Object o : sourceArray )
  ksess.insert( convertToMyFact( o ) );

I have constructed my rules as such:

rule "rule1"
when
   $f : MyFact( prop == "testVal" )
then
   copyToDestination( $f.prop, $f.index );
end

After running, however, the destination array appears in reverse order:
source[0] == destination[5]
source[1] == destination[4]
source[2] == destination[3]
source[3] == destination[2]
source[4] == destination[1]
source[5] == destination[0]

Which seems to make sense if the facts are evaluated as if they were
popped off a stack.  Is there any way to force Drools to use a list
instead?  Or should I just insert facts in reverse order?

I would like the order:
source[0] == destination[0]
source[1] == destination[1]
etc.

Thanks,
Dan