How to use Rete Algorithm

Question

How can i use Rete Algorithm in java?

Do i need to write my own algorithm implementation?

Or is there already implemented library available?

Answer 1

So this is a pretty old question, but ranks highly if you're googling for Rete Implementations, so I'll leave some info here.

The wikipedia entry is pretty good and here is a paper about Rete/UL which is according to Doorenbos more efficient than ReteII Doorenbos, 1995.

Some Implementations include:

• Drools for java
• Jess also java
• Wongi-Engine for ruby (I use this one) based on the same paper as listed above.
• Ruleby also ruby but defunct
• Mirmir clojure
• Clara Rules also clojure (added 4/20/15)
• Rete for Triples clojure (maybe defunct?)
• kongra's Rete haskell (wow) based on the same paper as listed above.
• and all of these

Its a really useful algorithm if you need to make decisions based on patterns of facts, and as a bonus, you'll have to learn some cool things about graphs and pattern matching.

Hope this is helpful!

Answer 2

A simple Google search for "Rete Algorithm Java" showed up this result (among others): http://java-source.net/open-source/rule-engines.

The first entry reads: Drools is an Object-Oriented Rule Engine for Java. Drools is an augmented implementation of Forgy's Rete algorithm tailored for the Java language.

So the answer seems to be: Yes, there already is a library that implements the algorithm you're looking for.

Answer 3

See the References section on the Wikipedia entry on the Rete Algorithm, it contains code snippets in both Pascal and LISP (?) style languages - nothing C-like, though.

Cheers,