[rules-users] Drools all lhs execute before all the rhs, i want to run sequentially

[Swindells, Thomas]

This isn't an if statement evaluated left to right with an && between each part.
Drools uses the rete algorithm to make execution more efficient.
Put very simply (and probably inaccurately) Rete creates an evaluation tree where inputs are put in the top and activations come out the end.
In this case the tree would have:
One node that evaluated condition1, this node outputs a list of all the facts that matches it.
A node for condition 2 which outputs a list all the facts that match that condition.
A node for the rule, this takes the outputs of the other two nodes and produces an activation for each pair of items (assuming condition 1 and 2 aren't related).

If you had another rule with condition1 and condition3 then they would both share the first node greatly improving efficiency and re-evaluation time.


Thomas

> -----Original Message-----
> From: rules-users-bounces at lists.jboss.org [mailto:rules-users-
> bounces at lists.jboss.org] On Behalf Of Saurabh Pandey
> Sent: 26 September 2011 08:15
> To: rules-users at lists.jboss.org
> Subject: Re: [rules-users] Drools all lhs execute before all the rhs, i want to
> run sequentially
>
> take a simple scenario:
> when
>  condition1
>  condition2
> then
>  ...
>
> Does the condition2 gets executed even if the condition1 is false, normally it
> should not because the conditions in the when are actually combined with an
> AND. Has anywhen tried this??
>
> --
> View this message in context: http://drools.46999.n3.nabble.com/Drools-all-
> lhs-execute-before-all-the-rhs-i-want-to-run-sequentially-
> tp3368215p3368464.html
> Sent from the Drools: User forum mailing list archive at Nabble.com.
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> rules-users mailing list
> rules-users at lists.jboss.org
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