3:04 a.m.
Hi,
In lots of rules in the drools planner examples the accumulate function is used in this
way:
rule "requiredCpuPowerTotal"
when
$computer : CloudComputer($cpuPower : cpuPower)
$requiredCpuPowerTotal : Number(intValue > $cpuPower) from accumulate(
CloudProcess(
computer == $computer,
$requiredCpuPower : requiredCpuPower),
sum($requiredCpuPower)
)
then
insertLogical(new IntConstraintOccurrence("requiredCpuPowerTotal",
ConstraintType.NEGATIVE_HARD,
$requiredCpuPowerTotal.intValue() - $cpuPower,
$computer));
end
(example from cloudBalancing).
Though, documentation says
(http://docs.jboss.org/drools/release/5.5.0.Final/drools-expert-docs/html_...)
one should this syntax:
<result pattern> from accumulate( <source pattern>,
init( <init code> ),
action( <action code> ),
reverse( <reverse code> ),
result( <result expression> ) )
Does this mean that the axemples could be optimized and that I should go for that syntaxt
as well rather than using the syntax like rule "requiredCpuPowerTotal" ?
Thanks
-----------------
http://www.codessentials.com - Your essential software, for free!
Follow us at http://twitter.com/#!/Codessentials
3:12 a.m.
There are currently 3 ways to write your accumulate pattern in drools:
1. The way you have pointed out containing all the different sections:
init, action, reverse and result. The problem with this syntax is that you
have to embed java code in your rules making them hard to read and
maintain. Following this syntax, if you want to reuse an accumulate
function you have to copy and paste it. This form of accumulate is highly
discouraged by drools team.
2. Use some of the predefined accumulate functions like sum(), avg(),
count(), etc.
3. If the predefined set of accumulate functions is not enough you can
create your accumulate function in a Java class and then register it in
drools and use it in your DRL. Please refer to the documentation for
further information.
Best Regards,
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Esteban Aliverti
- Blog @ http://ilesteban.wordpress.com
On Tue, Jan 22, 2013 at 10:04 AM, Michiel Vermandel <mvermand(a)yahoo.com>wrote:
Hi,
In lots of rules in the drools planner examples the accumulate function is
used in this way:
rule "requiredCpuPowerTotal"
when
$computer : CloudComputer($cpuPower : cpuPower)
$requiredCpuPowerTotal : Number(intValue > $cpuPower) from
accumulate(
CloudProcess(
computer == $computer,
$requiredCpuPower : requiredCpuPower),
sum($requiredCpuPower)
)
then
insertLogical(new IntConstraintOccurrence("requiredCpuPowerTotal",
ConstraintType.NEGATIVE_HARD,
$requiredCpuPowerTotal.intValue() - $cpuPower,
$computer));
end
(example from cloudBalancing).
Though, documentation says (
http://docs.jboss.org/drools/release/5.5.0.Final/drools-expert-docs/html_...)
one should this syntax:
<result pattern> from accumulate( <source pattern>,
init( <init code> ),
action( <action code> ),
reverse( <reverse code> ),
result( <result expression> ) )
Does this mean that the axemples could be optimized and that I should go
for that syntaxt as well rather than using the syntax like rule
"requiredCpuPowerTotal" ?
Thanks
-----------------
http://www.codessentials.com - Your essential software, for free!
Follow us at http://twitter.com/#!/Codessentials
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rules-users mailing list
rules-users(a)lists.jboss.org
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4:07 a.m.
You must have misinterpreted the Expert manual.
At #d0e6921, which you quote, it says that "Accumulate with inline custom code
is not a good practice for several reasons". So we have
1) from accumulate (as used in the Planner example)
2) Inline custom code
3) Java implementation
But there is a fourth way, see 4.8.3.7.4.1., Accumulate CE (preferred syntax)
This is the Planner example, rewritten:
$computer : CloudComputer($cpuPower : cpuPower)
accumulate( CloudProcess(
computer == $computer,
$requiredCpuPower : requiredCpuPower);
$requiredCpuPowerTotal : sum($requiredCpuPower),
$requiredCpuPowerTotal > $cpuPower )
-W
On 22/01/2013, Michiel Vermandel <mvermand(a)yahoo.com> wrote:
Hi,
In lots of rules in the drools planner examples the accumulate function is
used in this way:
rule "requiredCpuPowerTotal"
when
$computer : CloudComputer($cpuPower : cpuPower)
$requiredCpuPowerTotal : Number(intValue > $cpuPower) from
accumulate(
CloudProcess(
computer == $computer,
$requiredCpuPower : requiredCpuPower),
sum($requiredCpuPower)
)
then
insertLogical(new IntConstraintOccurrence("requiredCpuPowerTotal",
ConstraintType.NEGATIVE_HARD,
$requiredCpuPowerTotal.intValue() - $cpuPower,
$computer));
end
(example from cloudBalancing).
Though, documentation says
(http://docs.jboss.org/drools/release/5.5.0.Final/drools-expert-docs/html_...)
one should this syntax:
<result pattern> from accumulate( <source pattern>,
init( <init code> ),
action( <action code> ),
reverse( <reverse code> ),
result( <result expression> ) )
Does this mean that the axemples could be optimized and that I should go for
that syntaxt as well rather than using the syntax like rule
"requiredCpuPowerTotal" ?
Thanks
-----------------
http://www.codessentials.com - Your essential software, for free!
Follow us at http://twitter.com/#!/Codessentials
4327
days inactive
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days old
3 comments
4 participants
participants (4)
-
Esteban Aliverti -
Geoffrey De Smet -
Michiel Vermandel -
Wolfgang Laun