RE: [rules-users] Drools basic questions.

Hi, 1. The dollar sign has no significance. What appears to the left of the colon is simply an identifier binding the object\field to a variable. Some people prefix their identifiers with dollar signs so that identifiers are easier to see in code. $stilton : Cheese( type == "stilton" ) Cheesery( cheeses contains $stilton ) stilton : Cheese( type == "stilton" ) Cheesery( cheeses contains stilton ) some_identifier : Cheese( type == "stilton" ) Cheesery( cheeses contains some_identifier ) 2. - cheapStilton : Cheese( type == "stilton", price < 10 ) Binds a variable "cheapStilton" to a Fact (Object) of type Cheese where it's field "type" equals "stilton" and it's field "price" is less than 10. Both "type" and "price" are compared to literals. - cheapStilton : Cheese( type == "stilton", price < newPrice) Binds a variable "cheapStilton" to a Fact (Object) of type Cheese where it's field "type" equals "stilton" and it's field "price" is less than another identifier "newPrice". "Type" is compared to a literal and "price" is compared to a variable. The variable would need to have been bound somewhere else in the rule; for example:- Price( newPrice : price ) cheapStilton : Cheese( type == "stilton", price < newPrice) With kind regards, Mike -----Original Message----- From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Mithun Sent: 17 May 2007 06:04 To: rules-users(a)lists.jboss.org Subject: [rules-users] Drools basic questions. I am new to drools, so i have some basic doubts. 1. what does the dollar sign represent in the following rule? what is the difference when u prefix and dont prefix a variable with the dollar sign? - $stilton : Cheese( type == "stilton" ) Cheesery( cheeses contains $stilton ) 2. what is the difference between the following rule statements ? - cheapStilton : Cheese( type == "stilton", price < 10 ) and - cheapStilton : Cheese( type == "stilton", price < newPrice) how does the rule base get access to the variable newPrice, in the above rule statement? Please help. Thank you. -- View this message in context: http://www.nabble.com/Drools-basic-questions.-tf3770003.html#a10658753 Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users