Jess programming language

From Wikipedia, the free encyclopedia

Jess, a rule engine for the Java platform, is a superset of CLIPS programming language, developed by Ernest Friedman-Hill of Sandia National Labs. It was first written in late 1995.

It provides rule-based programming suitable for automating an expert system, and is often referred to as an expert system shell. In recent years, intelligent agent systems have also developed, which depend on a similar capability.

Rather than a procedural paradigm, where a single program has a loop that is activated only one time, the declarative paradigm used by Jess continuously applied a collection of rules to a collection of facts by a process called pattern matching. Rules can modify the collection of facts, or they can execute any Java code.

Jess can be used to build Java applets as well as full applications that use knowledge in the form of declarative rules to draw conclusions, and inferences. Since many rules may match many inputs, there are few effective general purpose matching algorithms. The Jess rules engine uses the Rete algorithm.

Code examples:

(bind ?x 100)

// x = 100

(defunction max (?a ?b)
  (if (> ?a ?b) then
     (return ?a)
  else
     (return ?b)))

(deffacts myroom
   (fact chair)
   (fact table)
   (fact bed)
)

(deftemplate my_car
   (slot color)
   (slot mileage)
   (slot value)
)

(assert (my_car (color red) (mileage 10000) (value 400)))

[edit] External Reference

• Official Website