Welcome! PECL The PHP Language Workbench Sebastian Bergmann http://sebastian-bergmann.de/ March 13 th 2008

PECL

The PHP Language Workbench

Sebastian Bergmann

http://sebastian-bergmann.de/

March 13 th 2008

Who I am Sebastian Bergmann Involved in the PHP Project since 2000 Author, Consultant, Coach, Trainer Developer for eZ Systems AS

Sebastian Bergmann

Involved in the PHP Project since 2000

Author, Consultant, Coach, Trainer

Developer for eZ Systems AS

Who are you? Your experience with PHP 5? PECL? Meta Programming? AOP?

Your experience with

PHP 5?

PECL?

Meta Programming?

AOP?

PHP Language Extensions PECL has extensions that add “normal” functionality to PHP and/or are “not so normal” Operator VLD Parsekit Parse Tree Runkit Intercept

PECL has extensions that

add “normal” functionality to PHP and/or

are “not so normal”

Operator

VLD

Parsekit

Parse Tree

Runkit

Intercept

ext/operator Operator Overloading C++, for instance, allows to overload operators such as + , - , * and / The programmer can decide on the semantics of these operators on a class-by-class basis Goal: Make the code more readable

Operator Overloading

C++, for instance, allows to overload operators such as + , - , * and /

The programmer can decide on the semantics of these operators on a class-by-class basis

Goal: Make the code more readable

ext/operator + - * / % << >> . .= | & ^ ~ ! ++ -- += -= *= /= %= <<= >>= |= &= ^= ~= === !== == != < <= > >=

+

-

*

/

%

<<

>>

.

.=

|

&

^

~

!

++

--

+=

-=

*=

/=

%=

<<=

>>=

|=

&=

^=

~=

===

!==

==

!=

<

<=

>

>=

ext/operator <?php class Fraction { public $numerator ; public $denominator ; public function __construct ( $n , $d = 1 ) { $this -> numerator = $n ; $this -> denominator = $d ; } } ?>

ext/operator <?php class Fraction { // ... public function __toString () { return $this -> numerator . '/' . $this -> denominator ; } } ?>

ext/operator <?php class Fraction { // ... public function __add ( Fraction $fraction ) { return new Fraction ( $this -> numerator * $fraction -> denominator + $fraction -> numerator * $this -> denominator , $this -> denominator * $fraction -> denominator ); } } ?>

ext/operator <?php require_once 'Fraction.php' ; $a = new Fraction ( 2 , 3 ); $b = new Fraction ( 4 , 2 ); print $a + $b ; ?> 16/6

VLD (Vulcan Logic Disassembler) Disassembler for PHP Bytecode alias vld=&quot;php -dvld.active=1 -dvld.execute=0&quot; Usefull for developers of the Zend Engine extensions for the Zend Engine such as Debuggers Optimizers But also for “curious PHP developers”

Disassembler for PHP Bytecode

alias vld=&quot;php -dvld.active=1 -dvld.execute=0&quot;

Usefull for developers of

the Zend Engine

extensions for the Zend Engine such as

Debuggers

Optimizers

But also for “curious PHP developers”

ext/parsekit Provides read access to the op arrays that make up PHP's bytecode API parsekit_compile_string() parsekit_compile_file() Return value: multi-dimensional array Usefull to (statically) analyze PHP code

Provides read access to the op arrays that make up PHP's bytecode

API

parsekit_compile_string()

parsekit_compile_file()

Return value: multi-dimensional array

Usefull to (statically) analyze PHP code

ext/parse_tree Provides access to the parse tree of PHP source code The tree Is returned as an XML document that can be transformed using XSLT, for instance and can be transformed back to PHP source code Usefull for Analysis and Refactoring of PHP source code Extending the syntax of PHP Example: AspectPHP

Provides access to the parse tree of PHP source code

The tree

Is returned as an XML document that

can be transformed using XSLT, for instance and

can be transformed back to PHP source code

Usefull for

Analysis and Refactoring of PHP source code

Extending the syntax of PHP

Example: AspectPHP

Interlude: AspectPHP Aspect-Oriented Programming with PHP following the example of AspectJ for Java Project in the Google Summer of Code 2006 ext/parse_tree is a by-product of this project

Aspect-Oriented Programming with PHP following the example of AspectJ for Java

Project in the Google Summer of Code 2006

ext/parse_tree is a by-product of this project

Interlude: Aspect-Orientation New modularization concept Quantification Execute code C when event E is triggered during the execution of program P Obliviousness Program P is oblivious to the code C , it does not provide hooks for the event E Functionality that would otherwise be scattered across the codebase and tangled with other functionality can be cleanly abstracted and encapsulated

New modularization concept

Quantification

Execute code C when event E is triggered during the execution of program P

Obliviousness

Program P is oblivious to the code C , it does not provide hooks for the event E

Functionality that would otherwise be scattered across the codebase and tangled with other functionality can be cleanly abstracted and encapsulated

Interlude: Aspect-Orientation New Object Join Point Method Call Join Point

Interlude: AspectPHP <?php aspect Singleton { public $instances = array (); pointcut newObject : new( SomeClass ( * )); around newObject { $className = $thisJoinPoint -> getClassName (); if (! isset ( $thisAspect -> instances [ $className ])) { $thisAspect -> instances [ $className ] = proceed (); } return $thisAspect -> instances [ $className ]; } private function SomeClass :: __clone () {} } ?>

Interlude: AspectPHP PHPAspect

ext/runkit Replace, rename, and delete classes, methods, and functions at runtime Define additional super-global variables Execute code in a sandbox

Replace, rename, and delete classes, methods, and functions at runtime

Define additional super-global variables

Execute code in a sandbox

ext/runkit <?php class Calculator {} $calculator = new Calculator ; runkit_method_add ( 'Calculator' , 'add' , '$a, $b' , 'return $a + $b;' , RUNKIT_ACC_PUBLIC ); print $calculator -> add ( 23 , 42 ); ?>

Interlude: GAP G eneric A spects for P HP Generic Join Point Model for PHP Framework for Pointcut Systems Supports Aspect Genericity An Advice is a “normal” PHP method $joinPoint o bject inside this method Default Pointcut System uses annotations to bind advice methods to join points

G eneric A spects for P HP

Generic Join Point Model for PHP

Framework for Pointcut Systems

Supports Aspect Genericity

An Advice is a “normal” PHP method

$joinPoint o bject inside this method

Default Pointcut System uses annotations to bind advice methods to join points

Interlude: GAP <?php /* @pointcut allMethodCalls : method(* *->*(..)); * @after allMethodCalls : LoggingAspect->log(); */ class LoggingAspect { public function log ( $joinPoint ) { printf ( &quot;%s->%s() called %s->%s()
&quot; , $joinPoint -> getSource ()-> getDeclaringClass () -> getName (), $joinPoint -> getSource ()-> getName (), $joinPoint -> getTarget ()-> getDeclaringClass () -> getName (), $joinPoint -> getTarget ()-> getName () ); } }

ext/runkit weaveMethodJoinPoint ( ReflectionMethod $method ) { runkit_method_rename ( $method -> getDeclaringClass ()-> getName (), $method -> getName (), '__GAP_' . $method -> getName () ); runkit_method_add ( $method -> getDeclaringClass ()-> getName (), $method -> getName (), self :: generateMethodParameters ( $method ), 'return GAP_Dispatcher::getInstance() ->methodCall(new GAP_JoinPoint_Method);' ); }

ext/intercept Intercept function calls Allows execution code before and after a function is executed Allows for the implementation of AOP-style before- and around-advices, but not around

Intercept function calls

Allows execution code before and after a function is executed

Allows for the implementation of AOP-style before- and around-advices, but not around

ext/intercept <?php function foo () { print &quot;foo()
&quot; ; } function before () { print &quot;before advice
&quot; ; } function after () { print &quot;after advice
&quot; ; } intercept_add ( 'foo' , 'before' , PRE_INTERCEPT ); intercept_add ( 'foo' , 'after' , POST_INTERCEPT ); foo ();

The End Thank you for your interest! These slides will be available shortly on http://sebastian-bergmann.de/talks/.

Thank you for your interest!

These slides will be available shortly on http://sebastian-bergmann.de/talks/.

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This presentation material is published under the Attribution-Share Alike 3.0 Unported license.

You are free:

to Share – to copy, distribute and transmit the work.

to Remix – to adapt the work.

Under the following conditions:

Attribution. You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).

Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under the same, similar or a compatible license.

For any reuse or distribution, you must make clear to others the license terms of this work.

Any of the above conditions can be waived if you get permission from the copyright holder.

Nothing in this license impairs or restricts the author's moral rights.