I get the following errors:

Rule Compilation error : [Rule name='no B for 2 minutes']
com/sample/Rule_no_B_for_2_minutes_0.java (7:571) : Main cannot be resolved

Rule Compilation error : [Rule name='B arrives']
com/sample/Rule_B_arrives_0.java (7:632) : Main cannot be resolved

It seems that 'Main.getClock()' can't be resolved.

Well, it's obvious that you can omit the println, or use some function returning the pseudo-time.

Besides, is it possible not to retract EventB when it arrives? Those events might be checked against other rules.

You can omit the retract, but then you must add no-loop true as in "ticker 120".

Out of interest in the last, what are other possible techniques?

Run a separate timer thread, i.e., a ticker written in Java.

-W

Best Regards,

Kevin Zhao

2010/11/1 Wolfgang Laun <wolfgang.laun@gmail.com>

Absence of events can only be detected by checking the past.
This means that a trigger must be inserted whenever it's time
to check the last two minutes. This check cannot be done in
a uniform way for all players because the arrival of an EventB
is the start of another 2 minute interval. The solution is based
on a ticker which inserts the trigger (Checker) whenever 120
seconds have gone by. (There are also other techniques to do this.)

declare EventB
@role( event )
end

declare Checker
@role( event )
end

rule "ticker 120"
no-loop true
timer(int:0s 1s)
when
    $p: Player( $index: index, $ticks: ticks )
then
    if( $ticks == 120 ){
        modify( $p ){ setTicks( 1 ) }
        insert( new Checker( $index ) );
    } else {
        modify( $p ){ setTicks( $ticks + 1 ) }
    }
end

rule "no B for 2 minutes"
when
    $c : Checker( $index: index )
    not EventB( index == $index, this before[0s,2m] $c )
then
    System.out.println( "at " + Main.getClock() + ": no B:" + $index + " in last 2 minutes" );
    retract( $c );
end

rule "B arrives"
when
    $p : Player( $index: index )
    $b : EventB( index == $index )
then
    System.out.println( "at " + Main.getClock() + ": B:" + $index + ", reset ticks" );
    modify( $p ){ setTicks( 0 ) }
    retract( $b );
end

2010/10/31 赵侃侃 <kevin223@gmail.com>

   this.session = createSession();
   SessionPseudoClock clock = session.getSessionClock();

   session.insert( new Player( 1 ) );
   session.insert( new Player( 2 ) );

   clock.advanceTime( 3*60, TimeUnit.SECONDS );
   session.insert(new EventB(1));

   session.fireAllRules();

   clock.advanceTime( 3*60, TimeUnit.SECONDS );
   session.fireAllRules();

   session.dispose();

The above code gives the following output:

no B:2 in last 2 minutes
no B:1 in last 2 minutes

what I expect is:

no B:2 in last 2 minutes
no B:2 in last 2 minutes
no B:1 in last 2 minutes

Any ideas?

Best Regards,
Kevin Zhao

2010/10/29 Wolfgang Laun <wolfgang.laun@gmail.com>
    System.out.println( "Test no B" );
    session = kBase.newStatefulKnowledgeSession( config, null );
    clock = session.getSessionClock();
    session.insert( new Player( 1 ) );
    clock.advanceTime( 3*60, TimeUnit.SECONDS );
    session.fireAllRules();
    session.dispose();

The rule fires with this test, (kBase in STREAM mode).
-W

2010/10/29 赵侃侃 <kevin223@gmail.com>

The "no B:x for 2 minutes" will not fire if nothing comes in even after 2minutes. e.g. if no characters get killed then no events will come in.
If I add a timer to this rule, say like timer (2m 1s), then the rule will fire every second after 2 minutes.

Best Regards,
Kevin

2010/10/29 Wolfgang Laun <wolfgang.laun@gmail.com>

OK; your original version somehow put me off the right track.
This rule will fire as soon as there is no B:n according to the
Player index for 2 minutes.

rule "no B:x for 2 minutes"
when
    $b : Player( $index: index )
    not ( EventB( index == $index) over window:time( 2m ) )
then
    System.out.println( "no B:" + $index + " in last 2 minutes" );
end

This would fire whenever there's no B at all for 2 minutes:

rule "no B for 2 minutes"
when
    not ( EventB() over window:time( 2m ) )
then
    System.out.println( "no B:" + $index + " in last 2 minutes" );
end

2010/10/28 赵侃侃 <kevin223@gmail.com>
My last mail should actually read:

A player may have multiple characters and the rule should fire when ALL of its characters live longer than 2 minutes. that's why "characters" do not have a unique identification and  there isn't any event representing a character birth.

Best Regards,
Kevin Zhao

在 2010年10月28日下午9:50，赵侃侃 <kevin223@gmail.com>写道：

A player may have multiple characters and the rule should fire when any of its characters live longer than 2 minutes. that's why "characters" do not have a unique identification and  there isn't any event representing a character birth.

Best Regards,
Kevin Zhao

2010/10/28 Wolfgang Laun <wolfgang.laun@gmail.com>

If EventB( index == 3 ) signifies that the "character" owned by player 3 has been killed: what is the event that this character has been born? Life is the time between birth and death; these two are well-defined (well, mostly) events, and they ought to be represented by clean-cut events in any application. Then it's no problem to write rules firing when a "character" lives longer or shorter than any time. Also, "characters" may have to have a unique identification beyond their player-owner.

If you are constantly shifting your specs, we won't be getting any closer to a solution, though.

-W

2010/10/28 赵侃侃 <kevin223@gmail.com>

To be honest, I don't quite understand the rules you wrote. Let me explain this a little bit with a real world scenario.
Assume this is an on-line game that EventB indicates a 'kill' event that a player is losing its character who might be killed by some other player.

The property index points to the player who owns this character. What I'm looking for here is to find out when a player's character survives in 2 minutes. The number of players in a game is at least 2 but can be up to any number.

Best Regards,
Kevin Zhao

2010/10/28 Wolfgang Laun <wolfgang.laun@gmail.com>

2010/10/28 赵侃侃 <kevin223@gmail.com>

Hello Wolfgang,

Index is just like the index in an array. the value can be any from 0 to the array length.
for the previous example, the length is 1 so index can be either 0 or 1. but in the real case, the length can be an arbitrary number.

another question, there are 2 rules here, do both of them have to be applied?

One creates and inserts the PatternConsumer which blocks repeated usage of the pair of EventB facts that have been successfully paired. Otherwise a sequence EventB:0, EventB:1, EventB:2 would fire 2 times.

If the positive condition is more complex, e.g., you need *all* index values 0,...,L-1 within 2m, then other conditions will be required (and that's what I meant with "more precisesly"). If any pair a,b from [0..L-1] will do, then the modified version (!=) should be OK.

-W

Best Regards,

Kevin Zhao

2010/10/28 Wolfgang Laun <wolfgang.laun@gmail.com>

Kindly state your requirements precisely.

Perhaps
   not ( EventB ( index != $index,... )
is what you need.
-W

2010/10/28 赵侃侃 <kevin223@gmail.com>

I haven't tested this rule, but what about the case that property index would have arbitrary number of possible values?

2010/10/27 Wolfgang Laun <wolfgang.laun@gmail.com>

Omitting the Entry Points:

rule "B-0-1-not OK"
when
$b : EventB( $index: index )
not ( PatternConsumer( id == "B01", events contains $b ) )
not ( EventB( index == (1 - $index), this after[0s,2m] $b ) )
then
System.out.println( "B:" + $index + ", but no B:" + (1-$index) );
end

rule "B-0-1"
when
$b1 : EventB( $index: index )
$b2 : EventB( index == (1 - $index), this after[0s,2m] $b1 )
then
insert( new PatternConsumer( "B01", $b1, $b2 ) );
System.out.println( "B:" + $index + "+B:" + (1-$index) );
end

-W

2010/10/27 赵侃侃 <kevin223@gmail.com>:

> Hello,
> With the help from the community I managed to get my first rule working, and
> I'm trying to write my second rule on my own but it just doesn't seem to
> work correctly.
> Here is the scenario, what I want is to identify a pattern that there's no
> EventB coming in within 2 minutes with a particular index value.
> For example, EventB would have a property named index and assume the value
> of index would be either 0 or 1.
> Before firing the rules, I would manually insert facts of possibleIndex with
> value 0 and 1 into the workingMemory.
> Within 2 minutes, if there only comes one EventB with index valued 0 then
> the system should report no EventB coming in with index value 1 in last 2
> minutes.
> Vice versa, in the case of only coming one EventB with index valued 1 then
> the system should report no EventB coming in with index value 0 in last 2
> minutes.
> If within 2 minutes, there comes 2 EventB with both value 0 and 1 then
> nothing should report.
> Here is what I wrote, but it doesn't seem to work correctly.
> I used a timer to fire this rule every 10 seconds because I don't think the
> rule would run automatically if I don't add that. (not too sure though)
> rule "no B in 2 minutes"
> timer (0 10s)
> when
> possibleIndex( $index : index ) from entry-point "Event stream"
> $p : PatternConsumer ( name == 'no B' && index == $index )
> not ( EventB( index == $index && this after[0ms,2m] $p) over window:time(2m)
> from entry-point "Event stream" )
> then
> PatternConsumer pc = new PatternConsumer( "no B", $index );
> insert(pc);
> System.out.println("no B in 2 minutes " + $index);
> end
> Best Regards,
> Kevin Zhao

> _______________________________________________
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> rules-users@lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>

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