Manual is not ready yet, so follows quick explanation ([] means
optional):
[variable :] <ReturnClass> ( [constraints] ) from collect( <SourceClass>
( [constraints] ) );
Example:
$cheeseList : ArrayList(size > 2) from collect( Cheese( type == $likes ) );
So, the above will collect all Cheese (source class) objects from
working memory, whose type is equal to the $likes bound variable, will
add them to a ArrayList (return class) and if the size of the array list
is greater than 2, it will propagate the tuple, binding $cheeseList
variable to that returned array list. You can use any class as a return,
as long as it implements Collection interface and has a default no arg
constructor.
Accumulate is similar, though more flexible but also more verbose:
[variable :] <ReturnClass> ( [constraints] ) from accumulate(
[innerVariable :] <SourceClass>( [constraints] ),
init( [initialCode] ),
action( [actionCode] ),
result( [resultExpression] ) );
Example:
$cheesery : Cheesery( totalAmount > 100 )
from accumulate( $cheese : Cheese( type == $likes ),
init( Cheesery cheesery = new
Cheesery(); ),
action( cheesery.addCheese(
$cheese ); ),
result( cheesery ) );
Accumulate will work similar to collect, but can return an object of
absolutelly any class, as long as it matches the return value of the
<resultExpression>. Accumulate will execute the <initCode> once for each
tuple, and right after that will execute the <actionCode> once for each
matching object from <SourceClass>. After that it will return the
<resultExpression> and verify if the result value matches the constraint
in the <ReturnClass> (if any).
It is easier to understand translating it to an imperative algorithm:
<initCode>
foreach matchingObject
<declare bound inner variables>
<actionCode>
end foreach
return <resultExpression>
Hope it helps. If anyone fancy helping to write the manual for them,
:) we appreciate.
[]s
Edson
Marcos Tengelmann wrote:
Edson,
Is the syntax explained somewhere?
-----Original Message-----
From: Edson Tirelli [mailto:[EMAIL PROTECTED]
Sent: quarta-feira, 22 de novembro de 2006 09:50
To: [email protected]
Subject: Re: [drools-user] Conditions in multiple objects
Adbeme,
Unfortunately 3.0.x versions don't have collect. The new version
(3.1m1) has (currently in trunk). More details here:
http://markproctor.blogspot.com/2006/11/jboss-rules-3.html
Examples of the new features:
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_Collect.drl
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_Accumulate.drl
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_AccumulateModify.drl
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_From.drl
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_From2.drl
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/test_FromWithParams.drl
[]s
Edson
adbeme adbeme wrote:
Hello,
It seems that is not possible to make rules with operators like
"collect" that affects the rule to a set of objects.
It is possible to simulate that behaviour of collect in some form?
I need to fire rules that have conditions over a set of objects (of
same type) but i don't know how to group conditions over multiple same
objects.
For example :
rule CarsStopped
when
$c:Car (stop = true) // here i need a collect, i want multiple
objects in one rule that then
print("The list of cars stoped is:$c);
end
It seems that "collect" doesnt exist. It is possible to simulate that ?
Actually i ame using JRules and want to use drools too, but i am
having dificulties to do what i can do with JRules.
Thank you very much for your responses.
--
---
Edson Tirelli
Software Engineer - JBoss Rules Core Developer
Office: +55 11 3124-6000
Mobile: +55 11 9218-4151
JBoss, a division of Red Hat @ www.jboss.com
IT executives: Red Hat still #1 for value
http://www.redhat.com/promo/vendor/
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---
Edson Tirelli
Software Engineer - JBoss Rules Core Developer
Office: +55 11 3124-6000
Mobile: +55 11 9218-4151
JBoss, a division of Red Hat @ www.jboss.com
IT executives: Red Hat still #1 for value
http://www.redhat.com/promo/vendor/
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