[rules-users] Salience

[Wolfgang Laun]

Either you define a rule covering all "else" cases, which, in your
case, could be

rule "#catch-all"
when
$i : Item(  type != 1 && != 2  )
then
retract ($i)
// do something...
end

or you do  rely on salience, which, in this case is not quite so "bad practice".

It depends:  if the "catch all" is there to detect unexpected data,
it's ok; if it is there just to cover several cases the programmer is
too lazy to code in the ordinary way, then it might be considered "bad
practice".

-W



On 19 January 2011 19:17, huionn <huionn at gmail.com> wrote:
>
> If I have a rule like below:
>
> rule "#1"
> when
> $i : Item(type == 1)
> then
> retract ($i)
> // do something...
> end
>
> rule "#2"
> when
> $i : Item(type == 2)
> then
> retract ($i)
> // do something...
> end
>
> // to handle other type of Item
> rule "#catch-all"
> salience -10
> when
> $i : Item()
> then
> retract ($i)
> // do something...
> end
>
> As it is known, reliance on salience is bad practice and its order is not
> guaranteed (as shown in Sudoku example).
>
> My question is: what is the simple and good practice to emulate "else" (rule
> "#catch-all") without reliance on salience? It seems ruleflow is not
> applicable here as well.
>
>
> Thanks and best regards.
> --
> View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/Salience-tp2289179p2289179.html
> Sent from the Drools - User mailing list archive at Nabble.com.
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