Jess Language

JESS

Jess stands for "Java Expert System Shell". Jess is a powerful rule based language, this provides the capability to match patterns and perform actions accordingly.

Jess with Java

Anything that can be done in Java can be done in Jess. Jess can be used to develop even Applets. Java functions can be called from Jess. Jess has very limited data structures, but Java's data structures can be used by importing them.

Rules

Rules are typically if.......then statements. Usually procedural languages too have these if.. then statements, then what is the need of Jess?

Need of Jess

In procedural programming, program controls the execution sequence of if.. then statements. That is the execution order (firing order) of, if.. then statements is decided prior to the execution. Whereas in Jess, a rule based language it is the rule engine that decides the execution sequence of if .. then statements.

This might seem like program has no control or the developer has no control over the code, so why should one use it? the beauty of Jess or any other rule based language is, the execution sequence will be in sync with the data provided. That is an if..else statement executes if the data supplied matches that particular statement. So in this way it is very fast and reliable.

All that a developer should do is to write Rules or the if.. else conditions and provide those to the rule engine, then rule engine takes care of executing those Rules basing on the data provided.

to be continued........... Please provide your comments or suggestions.