Re: [rules-users] newbie question on "when" condition syntax
Glad my hasty original reply has been ripped apart ;-) Goes to show that everybody has something new to learn. Thanks to everyone for the corrections (and simpler, correct, solution!). Mike On 02/05/2008, mashup <[EMAIL PROTECTED]> wrote: > > > Ahhh I wondered about that, thanks. Again, now I see it, it makes complete > sense. This drools stuff is actually pretty damn good! > > Richard > > Chris Woodrow wrote: > > > > You're right, if you want to do this with 2 facts, you'll need to do : > > > > $test : Test( $y : y ) > > Test( > > this == $test, > > x == ($y + 1) ) > > > > Chris > > > > 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > > > >> On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: > >> > >> > The "when" section matches fact (object) patterns, so your > requirement > >> > could be written as:- > >> > > >> > when there is a Test Fact 'A' and another Test Fact 'B' where "the > 'x' > >> > property of 'A'" equals "the 'y' property of fact 'B' plus 1" > then. > >> > > >> > This would become:- > >> > > >> > rule "Rule 1" > >> > when > >> > Test( $y : y ) > >> > Test( x == ($y + 1) ) > >> > > >> > >> Actually, please correct me if I am mistaken, but is this condition > >> correct? I believe that the original question is that for a single > >> instance of class Test t, fire the rule when t.x == t.y + 1 (where 't' > >> refers to the *same* instance of class Test). I believe the rule above > >> would match any instance of class Test whose x value is equal to the > >> value of the instance field y from *any* instance of class Test plus 1. > >> Does that make sense? > >> ___ > >> rules-users mailing list > >> rules-users@lists.jboss.org > >> https://lists.jboss.org/mailman/listinfo/rules-users > >> > > > > ___ > > rules-users mailing list > > rules-users@lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > > -- > View this message in context: > http://www.nabble.com/newbie-question-on-%22when%22-condition-syntax-tp17015309p17028019.html > Sent from the drools - user mailing list archive at Nabble.com. > > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
Ahhh I wondered about that, thanks. Again, now I see it, it makes complete sense. This drools stuff is actually pretty damn good! Richard Chris Woodrow wrote: > > You're right, if you want to do this with 2 facts, you'll need to do : > > $test : Test( $y : y ) > Test( > this == $test, > x == ($y + 1) ) > > Chris > > 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > >> On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: >> >> > The "when" section matches fact (object) patterns, so your requirement >> > could be written as:- >> > >> > when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' >> > property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. >> > >> > This would become:- >> > >> > rule "Rule 1" >> > when >> > Test( $y : y ) >> > Test( x == ($y + 1) ) >> > >> >> Actually, please correct me if I am mistaken, but is this condition >> correct? I believe that the original question is that for a single >> instance of class Test t, fire the rule when t.x == t.y + 1 (where 't' >> refers to the *same* instance of class Test). I believe the rule above >> would match any instance of class Test whose x value is equal to the >> value of the instance field y from *any* instance of class Test plus 1. >> Does that make sense? >> ___ >> rules-users mailing list >> rules-users@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> > > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- View this message in context: http://www.nabble.com/newbie-question-on-%22when%22-condition-syntax-tp17015309p17028019.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
You're right, if you want to do this with 2 facts, you'll need to do : $test : Test( $y : y ) Test( this == $test, x == ($y + 1) ) Chris 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: > > > The "when" section matches fact (object) patterns, so your requirement > > could be written as:- > > > > when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' > > property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. > > > > This would become:- > > > > rule "Rule 1" > > when > > Test( $y : y ) > > Test( x == ($y + 1) ) > > > > Actually, please correct me if I am mistaken, but is this condition > correct? I believe that the original question is that for a single > instance of class Test t, fire the rule when t.x == t.y + 1 (where 't' > refers to the *same* instance of class Test). I believe the rule above > would match any instance of class Test whose x value is equal to the > value of the instance field y from *any* instance of class Test plus 1. > Does that make sense? > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
Thanks Chris, that does work. oh man, I tried something so similar to that with the parenethisis last night using my "programming by trial and error" methodology. many thanks to everyone who replied, it's all been a great help! Richard Chris Woodrow wrote: > > Hi, > even > Test (y == (x + 1)) > works. > > Richard : I think you should take a look at this before planning doing > complicated calculations with drools > http://lists.jboss.org/pipermail/rules-users/2008-April/005247.html but it > might be fixed now. > > Chris > > > 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > >> On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: >> >> > The "when" section matches fact (object) patterns, so your requirement >> > could be written as:- >> > >> > when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' >> > property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. >> > >> > This would become:- >> > >> > rule "Rule 1" >> > when >> > Test( $y : y ) >> > Test( x == ($y + 1) ) >> > >> >> Could you combine these conditions? As in: >> >> when >>Test($y : y, x == $y + 1) >> //... >> ___ >> rules-users mailing list >> rules-users@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> > > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- View this message in context: http://www.nabble.com/newbie-question-on-%22when%22-condition-syntax-tp17015309p17026473.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
wow, you guys are good, nice observation Raffi I had not considered that but this is all making me comprehend how Drools works. Actually I think I need to switch my brain on! Java is so easy it doesn't tend to require much thought, now I'm having to think about this stuff it hurts :-) thanks Richard Raffi Khatchadourian wrote: > > On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: >>The "when" section matches fact (object) patterns, so your requirement >>could be written as:- >> >>when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' >>property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. >> >>This would become:- >> >>rule "Rule 1" >>when >>Test( $y : y ) >>Test( x == ($y + 1) ) > > Actually, please correct me if I am mistaken, but is this condition > correct? I believe that the original question is that for a single > instance of class Test t, fire the rule when t.x == t.y + 1 (where 't' > refers to the *same* instance of class Test). I believe the rule above > would match any instance of class Test whose x value is equal to the > value of the instance field y from *any* instance of class Test plus 1. > Does that make sense? > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- View this message in context: http://www.nabble.com/newbie-question-on-%22when%22-condition-syntax-tp17015309p17026266.html Sent from the drools - user mailing list archive at Nabble.com. ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: The "when" section matches fact (object) patterns, so your requirement could be written as:- when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. This would become:- rule "Rule 1" when Test( $y : y ) Test( x == ($y + 1) ) Actually, please correct me if I am mistaken, but is this condition correct? I believe that the original question is that for a single instance of class Test t, fire the rule when t.x == t.y + 1 (where 't' refers to the *same* instance of class Test). I believe the rule above would match any instance of class Test whose x value is equal to the value of the instance field y from *any* instance of class Test plus 1. Does that make sense? ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
Yes, newest mvel version works fine, but that problem only happened when using mvel dialect. For java, just do as Chris mentioned: when Test( y == (x+1) ) then And it will work. The () is needed to tell the engine that what is inside is a semantic code block, i.e., an expression that will return a value to be compared to y. []s Edson 2008/5/2 Chris Woodrow <[EMAIL PROTECTED]>: > Hi, > even > Test (y == (x + 1)) > works. > > Richard : I think you should take a look at this before planning doing > complicated calculations with drools > http://lists.jboss.org/pipermail/rules-users/2008-April/005247.html but it > might be fixed now. > > Chris > > > 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > > On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: > > > > > The "when" section matches fact (object) patterns, so your requirement > > > could be written as:- > > > > > > when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' > > > property of 'A'" equals "the 'y' property of fact 'B' plus 1" > > > then. > > > > > > This would become:- > > > > > > rule "Rule 1" > > > when > > > Test( $y : y ) > > > Test( x == ($y + 1) ) > > > > > > > Could you combine these conditions? As in: > > > > when > >Test($y : y, x == $y + 1) > > //... > > ___ > > rules-users mailing list > > rules-users@lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/rules-users > > > > > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- Edson Tirelli JBoss Drools Core Development Office: +55 11 3529-6000 Mobile: +55 11 9287-5646 JBoss, a division of Red Hat @ www.jboss.com ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
Hi, even Test (y == (x + 1)) works. Richard : I think you should take a look at this before planning doing complicated calculations with drools http://lists.jboss.org/pipermail/rules-users/2008-April/005247.html but it might be fixed now. Chris 2008/5/2 Raffi Khatchadourian <[EMAIL PROTECTED]>: > On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: > > > The "when" section matches fact (object) patterns, so your requirement > > could be written as:- > > > > when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' > > property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. > > > > This would become:- > > > > rule "Rule 1" > > when > > Test( $y : y ) > > Test( x == ($y + 1) ) > > > > Could you combine these conditions? As in: > > when >Test($y : y, x == $y + 1) > //... > ___ > rules-users mailing list > rules-users@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
On Fri 2.May'08 at 10:05:20 +0100, Anstis, Michael (M.) wrote: The "when" section matches fact (object) patterns, so your requirement could be written as:- when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x' property of 'A'" equals "the 'y' property of fact 'B' plus 1" then. This would become:- rule "Rule 1" when Test( $y : y ) Test( x == ($y + 1) ) Could you combine these conditions? As in: when Test($y : y, x == $y + 1) //... ___ rules-users mailing list rules-users@lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users
RE: [rules-users] newbie question on "when" condition syntax
Hi Richard,
Glad I can be of help (this forum as a whole is actually very helpful).
Reading your email you understand me correctly (you even picked up on the
implicit AND between pattern matches).
With a bit of imagination complex problems can be solved with Drools; just
like programming you need to adjust your mindset sometimes and try a
different tact.
Personally, if your rules are not user-facing, I wouldn't worry about DSL -
even if they do don't worry for the time being!
Make sure to read the excellent manual, many people have put a lot of work
into this and it is invaluable.
Read about "dialect" to answer your question about rule language, to save me
copy and pasting.
Good luck,
Mike
_
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Richard Bremner
Sent: 02 May 2008 11:38
To: Rules Users List
Subject: Re: [rules-users] newbie question on "when" condition syntax
Hi Mike,
Thanks very much, after a few minutes of staring I think I have understood
your very well put answer!
If I understand you right, what is happening is:
Test( $y : y )
This means, WHEN there is an instance of Test, assign the value of its "y"
property to $y
AND
WHEN there is an instance of Test where it's "x" property is equal to $y + 1
THEN fire.
I think I understand that. I am going to need to do this with some pretty
complicated formulae, containing up to 8 different variables. I have a fixed
data set and need to find certain patterns in them based on the formulae. I
have most of the program figured out, my only trouble is expressing my
formulae in the correct syntax. I will try to extend this principle you have
explained to me and hope it can cope with the extra complication... unless
there would be a better way to achieve this?
I am really sorry but I am totally new to drools - but am committed to using
it on a project so I guess I'm going to get to know it pretty well :-)
I read briefly that one can define a DSL, I might look at this eventually to
build an easier mechanism for expressing my formulae - if that can be
achieved using a DSL.
Can the whole rule be defined in Groovy/Java - if so I might be easier doing
that. I have so much work to do!
many thanks
Richard
2008/5/2 Anstis, Michael (M.) <[EMAIL PROTECTED]>:
Hi Richard,
The "when" section matches fact (object) patterns, so your requirement could
be written as:-
when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x'
property of 'A'" equals "the 'y' property of fact 'B' plus 1" then.
This would become:-
rule "Rule 1"
when
Test( $y : y )
Test( x == ($y + 1) )
then
System.out.println("Rule 1 matches");
end
By default both patterns can match the same object, so test data:-
A : x = 1, y = 1
B : x = 2, y = 1
Will cause the rule to activate twice:-
A and B
B and B
With kind regards,
Mike
_
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Richard Bremner
Sent: 02 May 2008 08:53
To: rules-users@lists.jboss.org
Subject: [rules-users] newbie question on "when" condition syntax
Hi,
say I have a class with two fields, x and y:
public class Test {
int x = 1;
int y = 2;
getters/setters...
}
I would like a rule which fires when y = x + 1
my initial thought would be something like:
rule "Rule 1"
when
test : Test (y == x + 1)
then
System.out.println("Rule 1 matches.");
end
but this is invalid syntax and I can not find any examples of such a rule.
I'm doing my best but reading the manual etc. I'm struggling with the syntax
here and can't figure it out.
any help really appreciated!
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
smime.p7s
Description: S/MIME cryptographic signature
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
Re: [rules-users] newbie question on "when" condition syntax
Hi Mike,
Thanks very much, after a few minutes of staring I think I have understood
your very well put answer!
If I understand you right, what is happening is:
Test( $y : y )
This means, WHEN there is an instance of Test, assign the value of its "y"
property to $y
AND
WHEN there is an instance of Test where it's "x" property is equal to $y + 1
THEN fire.
I think I understand that. I am going to need to do this with some pretty
complicated formulae, containing up to 8 different variables. I have a fixed
data set and need to find certain patterns in them based on the formulae. I
have most of the program figured out, my only trouble is expressing my
formulae in the correct syntax. I will try to extend this principle you have
explained to me and hope it can cope with the extra complication... unless
there would be a better way to achieve this?
I am really sorry but I am totally new to drools - but am committed to using
it on a project so I guess I'm going to get to know it pretty well :-)
I read briefly that one can define a DSL, I might look at this eventually to
build an easier mechanism for expressing my formulae - if that can be
achieved using a DSL.
Can the whole rule be defined in Groovy/Java - if so I might be easier doing
that. I have so much work to do!
many thanks
Richard
2008/5/2 Anstis, Michael (M.) <[EMAIL PROTECTED]>:
> Hi Richard,
>
> The "when" section matches fact (object) patterns, so your requirement
> could be written as:-
>
> when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x'
> property of 'A'" equals "the 'y' property of fact 'B' plus 1" then.
>
> This would become:-
>
> rule "Rule 1"
> when
> Test( $y : y )
> Test( x == ($y + 1) )
> then
> System.out.println("Rule 1 matches");
> end
>
> By default both patterns can match the same object, so test data:-
>
> A : x = 1, y = 1
> B : x = 2, y = 1
>
> Will cause the rule to activate twice:-
>
> A and B
> B and B
>
> With kind regards,
>
> Mike
>
> --
> *From:* [EMAIL PROTECTED] [mailto:
> [EMAIL PROTECTED] *On Behalf Of *Richard Bremner
> *Sent:* 02 May 2008 08:53
> *To:* rules-users@lists.jboss.org
> *Subject:* [rules-users] newbie question on "when" condition syntax
>
> Hi,
>
> say I have a class with two fields, x and y:
>
> public class Test {
> int x = 1;
> int y = 2;
>
> getters/setters...
> }
>
>
> I would like a rule which fires when y = x + 1
>
> my initial thought would be something like:
>
> rule "Rule 1"
>
> when
> test : Test (y == x + 1)
> then
> System.out.println("Rule 1 matches.");
>
> end
>
>
> but this is invalid syntax and I can not find any examples of such a rule.
> I'm doing my best but reading the manual etc. I'm struggling with the syntax
> here and can't figure it out.
>
> any help really appreciated!
>
>
> ___
> rules-users mailing list
> rules-users@lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
RE: [rules-users] newbie question on "when" condition syntax
Hi Richard,
The "when" section matches fact (object) patterns, so your requirement could
be written as:-
when there is a Test Fact 'A' and another Test Fact 'B' where "the 'x'
property of 'A'" equals "the 'y' property of fact 'B' plus 1" then.
This would become:-
rule "Rule 1"
when
Test( $y : y )
Test( x == ($y + 1) )
then
System.out.println("Rule 1 matches");
end
By default both patterns can match the same object, so test data:-
A : x = 1, y = 1
B : x = 2, y = 1
Will cause the rule to activate twice:-
A and B
B and B
With kind regards,
Mike
_
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Richard Bremner
Sent: 02 May 2008 08:53
To: rules-users@lists.jboss.org
Subject: [rules-users] newbie question on "when" condition syntax
Hi,
say I have a class with two fields, x and y:
public class Test {
int x = 1;
int y = 2;
getters/setters...
}
I would like a rule which fires when y = x + 1
my initial thought would be something like:
rule "Rule 1"
when
test : Test (y == x + 1)
then
System.out.println("Rule 1 matches.");
end
but this is invalid syntax and I can not find any examples of such a rule.
I'm doing my best but reading the manual etc. I'm struggling with the syntax
here and can't figure it out.
any help really appreciated!
smime.p7s
Description: S/MIME cryptographic signature
___
rules-users mailing list
rules-users@lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
