Rulez, a minimalistic rule evaluation engine.
C#
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
Rulez.Tests
Rulez
.gitignore
LICENSE.TXT
README.md
Rulez.sln

README.md

#Rulez

Rulez is the simplest possible Rule engine I can imagine for .NET.

##Facts and Rules

A Rule is specified by a .NET delegate (Action), that uses Facts for its computation.

To specify a Rule, use

Rule.activate(Action);

A Fact represents a mutable value. To create a Fact, use either

var integerValue = Fact.of(10);

or

var myInt = Fact.of<int>();

To change a Fact, assign a value to it:

myInt.Value = 4;

A Rule is evaluated in the context of the current Dispatcher.

While a Rule is evaluated, all Facts that are accessed are tracked.

A Rule has a lifetime. When it is active, it is automatically reevaluated as soon one of its referred Facts change. To deactivate a Rule call Dispose() on the return value of Rule.activate().

Rules may change other Facts.

For example, the following code keeps the result variable always at two times the input variable:

var input = Fact.of(0);
int result = 0;
Rule.activate(() => result = input.Value*2);

Note that the evaluation is deferred through the .NET Dispatcher. This means that the evaluation results may not be updated immediately.

##RuleSets

A RuleSet combines multiple Rules together.

To create a custom RuleSet, create a class that derives from RuleSet.

To add a Rule to your RuleSet, create a method that contains the Rule logic and attribute it with [Rule].

Any [Rule] attributed method in a RuleSet derived class is automatically activated as a Rule when the RuleSet class is instantiated.

To deactivate the RuleSet call its Dispose() method.

TBD: Examples