This little plugin is a extension for embed the wonderful rule engine CLIPS into PHP.

Before this extension, there is another PHP extension about CLIPS with a nice name phlips.

So, why I need to create another PHP extension?

1. phlips is long dead, the last active news of this project is at date January 19, 2005.
2. phlips is not a well designed framework to integrate CLIPS into PHP's environment, it is just a wrapper for all the CLIPS APIs

So, I choose to write a PHP extension on my own.

CLIPS is a forward-chaining rule-based programming language written in C that also provides procedural and object-oriented programming facilities.

1. For most rule based logic, it is easy and fast to write rules and execute them in the rule engine than to write very complex codes
2. The rules a much more easier to customize than the code
3. CLIPS lacks many useful functions(for example the regex support, can't connect to any datasource), but can get this from PHP
4. CLIPS is very very fast, here is the result of how fast it should be:

The code to calculate fibo 100

(defglobal ?*count* = 100)
(defrule fibo
	?n <- (n ?x ?xv)
	(n ?y&:(and (= (+ ?x 1) ?y) (<= ?y ?*count*)) ?yv)
		=>
	(retract ?n)
	(assert (n (+ ?y 1) (+ ?xv ?yv))))
(defrule output
	(n ?y&:(= ?y ?*count*) ?v)
		=>
	(printout t "The fibo of " ?y " is " ?v crlf))
(assert (n 1 1))
(assert (n 2 1))
(run)

and the result:

The fibo of 100 is 3736710778780434371
pclips fibo.rules  0.03s user 0.01s system 89% cpu 0.046 total

For it'll take about 0.04s to initliaze the PHP and the php-clips extension.

PHP 5.6.4 (cli) (built: Dec 23 2014 11:42:26) (DEBUG)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2014 Zend Technologies
	with Xdebug v2.2.6, Copyright (c) 2002-2014, by Derick Rethans
	php -v  0.02s user 0.01s system 82% cpu 0.030 total

The CLIPS code is distributed with this code, and will be compile into the extension, so you need nothing else to installed.

You can just call php's method(all in the current run context) in clips like this:

(php_call "print_r" (create$ 1 2 "3" Four))

And get result:

Array
(
	[0] => 1
	[1] => 2
	[2] => 3
	[3] => Four
)

This is the main feature of php-clips, you can do this in php-clips:

class Dummy { 
	/** @ClipsMulti */
	public $args;
	public $num;

	public function __construct($args) {
		$this->args = $args;
		$this->num = count(num);
	}
}

$clips->assertFacts(new Dummy(array('hello', 'world')));

and get the fact of:

(Dummy (args "hello" "world") (num 2))

The annotation support is based on the wonderful php annotation library addendum.

php-clips also provied a context to let CLIPS access PHP's object directly by using CLIPS's object name;

Here is the example(the array is translated into multiple fields automaticly): $clips->dummy = new Dummy(array('hello', 'world'));

(printout t "The args is " (php_property [dummy] "args"))

And you will get

"hello" "world"

The installation of this plugin is very easy, just like other php extensions:

1. git clone https://github.com/guitarpoet/php-clips.git
2. cd php-clips
3. phpize
4. ./configure
5. make && make install

Feel free to play with it, and contact me if you found a bug or have any intresting ideas.