PHP 5.3: New Language Features

PHP 5.3: New Language Features Sebastian Bergmann July 14th 2009

Who I am  Sebastian Bergmann  Involved in the PHP project since 2000  Creator of PHPUnit  Co-Founder and Principal Consultant with thePHP.cc

PHP 5.3 New Language Features  Lambda Functions  Closures  Functors  Late Static Binding Namespaces  goto

PHP 5.3 Other Improvements  New extensions  phar, intl, fileinfo  Garbage Collector  MySQL Native Driver  Improved Windows support

PHP 5.3 Performance Improvements 30 20 10 0 PHP 5.0.5 PHP 5.1.6 PHP 5.2.10 PHP 5.3.0

Lambda Functions In a nutshell Anonymous functions that  are declared on-the-fly,  can be assigned to a variable,  and passed to other functions

Lambda Functions Usage <?php $function = function() { print 'Hello World!'; }; ?>

Lambda Functions Usage <?php $function = function() { print 'Hello World!'; }; $function(); ?> Hello World!

Lambda Functions Usage <?php $function = function() { print 'Hello World!'; }; call_user_func($function); ?> Hello World!

Lambda Functions Usage <?php $function = function() { print 'Hello World!'; }; call_user_func_array($function, array()); ?> Hello World!

Lambda Functions Usage Scenarios <?php $list = array(22, 4, 19, 78); usort( $list, function ($a, $b) { if ($a == $b) return 0; return ($a < $b) ? -1 : 1; } ); print_r($list); ?> Array ( [0] => 4 [1] => 19 [2] => 22 [3] => 78 )

Lambda Functions Usage Scenarios <?php print_r( array_map( function ($n) { return($n * $n * $n); }, array(1, 2, 3, 4, 5) ) ); ?> Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 )

Lambda Functions Prior to PHP 5.3 <?php $function = create_function('', 'print "Hello World!";'); $function(); ?> Hello World!

Lambda Functions Prior to PHP 5.3 <?php $function = create_function('', 'print "Hello World!";'); call_user_func($function); ?> Hello World!

Lambda Functions Prior to PHP 5.3 <?php $function = create_function('', 'print "Hello World!";'); call_user_func_array($function, array()); ?> Hello World!

Closures In a nutshell Anonymous functions that  are declared on-the-fly,  can be assigned to a variable,  passed to other functions,  and remember what happens around them

Closures Lexical Variables <?php $string = 'Hello World!'; $function = function() use ($string) { print $string; }; $function(); ?> Hello World!

Closures Lexical Variables <?php $plus_this = function($num) { return function($arg) use ($num) { return $arg + $num; }; }; print_r( array_map( $plus_this(100), array(1, 2, 3) ) ); ?> Array ( [0] => 101 [1] => 102 [2] => 103 )

Closures Y-Combinator <?php function Y($F) { $func = function ($f) { return $f($f); }; return $func( function ($f) use($F) { return $F( function ($x) use($f) { $ff = $f($f); return $ff($x); } ); } ); } http://en.wikipedia.org/wiki/Fixed_point_combinator

Closures Lexical Variables with references <?php $x = 1; $function = function() use ($x) { print $x . "n"; }; $function(); $x = 2; $function(); print "n"; $x = 1; $function = function() use (&$x) { print $x . "n"; }; $function(); $x = 2; $function(); ?> 1 1 1 2

Closures Reflection API <?php $function = function($a, $b) { return $a + $b; }; $reflector = new ReflectionFunction($function); print $reflector; ?> Closure [ <user> function {closure} ] { @@ /home/sb/closure_reflection.php 2 - 2 - Parameters [2] { Parameter #0 [ <required> $a ] Parameter #1 [ <required> $b ] } }

Functors In a nutshell  Allow an object to be invoked or called as if it were an ordinary function  Can be used to implement stateful callbacks  Also called function objects, functionals or functionoids

Functors Usage <?php class Example { public function __invoke() { print __METHOD__ . "n"; } } $object = new Example; $object(); ?> Example::__invoke

Static Binding Early Static Binding <?php class Base { public static function a() { print __METHOD__ . "n"; self::b(); } public static function b() { print __METHOD__ . "n"; } } class Child extends Base { public static function b() { print __METHOD__ . "n"; } } Child::a(); ?> Base::a Base::b

Static Binding Late Static Binding <?php class Base { public static function a() { print __METHOD__ . "n"; static::b(); } public static function b() { print __METHOD__ . "n"; } } class Child extends Base { public static function b() { print __METHOD__ . "n"; } } Child::a(); ?> Base::a Child::b

Namespaces Declaration a.php <?php namespace project; const ANSWER = 42; class SomeClass {} function do_something() {} ?>

Namespaces Fully qualified names a.php <?php namespace project; const ANSWER = 42; class SomeClass {} function do_something() {} ?> b.php <?php require 'a.php'; print projectANSWER; $object = new projectSomeClass; projectdo_something(); ?>

Namespaces Import from namespace into local scope a.php <?php namespace project; const ANSWER = 42; class SomeClass {} function do_something() {} ?> c.php <?php require 'a.php'; use projectSomeClass; $object = new SomeClass; ?>

Namespaces Import from namespace into local scope (conflict) a.php <?php namespace project; const ANSWER = 42; class SomeClass {} function do_something() {} ?> c.php <?php class SomeClass {} require 'a.php'; use projectSomeClass; ?> Fatal error: Cannot use projectSomeClass as SomeClass because the name is already in use in /tmp/c.php on line 6

Namespaces Import from namespace into local scope with alias a.php <?php namespace project; const ANSWER = 42; class SomeClass {} function do_something() {} ?> d.php <?php class SomeClass {} require 'a.php'; use projectSomeClass as Foo; ?>

The End Thank you for your interest! These slides will be posted on http://slideshare.net/sebastian_bergmann

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PHP 5.3: New Language Features

by Sebastian Bergmann on Jul 16, 2009

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PHP 5.3: New Language Features — Presentation Transcript