php-coding-standards.markdown

@@ -151,3 +151,79 @@ class FooBar {
 
 [PSR-2](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md)
 
+
+
+Autoloading Standard
+====================
+
+The following describes the mandatory requirements that must be adhered
+to for autoloader interoperability.
+
+Mandatory
+---------
+
+* A fully-qualified namespace and class must have the following
+  structure `\<Vendor Name>\(<Namespace>\)*<Class Name>`
+* Each namespace must have a top-level namespace ("Vendor Name").
+* Each namespace can have as many sub-namespaces as it wishes.
+* Each namespace separator is converted to a `DIRECTORY_SEPARATOR` when
+  loading from the file system.
+* Each `_` character in the CLASS NAME is converted to a
+  `DIRECTORY_SEPARATOR`. The `_` character has no special meaning in the
+  namespace.
+* The fully-qualified namespace and class is suffixed with `.php` when
+  loading from the file system.
+* Alphabetic characters in vendor names, namespaces, and class names may
+  be of any combination of lower case and upper case.
+
+Examples
+--------
+
+* `\Doctrine\Common\IsolatedClassLoader` => `/path/to/project/lib/vendor/Doctrine/Common/IsolatedClassLoader.php`
+* `\Symfony\Core\Request` => `/path/to/project/lib/vendor/Symfony/Core/Request.php`
+* `\Zend\Acl` => `/path/to/project/lib/vendor/Zend/Acl.php`
+* `\Zend\Mail\Message` => `/path/to/project/lib/vendor/Zend/Mail/Message.php`
+
+Underscores in Namespaces and Class Names
+-----------------------------------------
+
+* `\namespace\package\Class_Name` => `/path/to/project/lib/vendor/namespace/package/Class/Name.php`
+* `\namespace\package_name\Class_Name` => `/path/to/project/lib/vendor/namespace/package_name/Class/Name.php`
+
+The standards we set here should be the lowest common denominator for
+painless autoloader interoperability. You can test that you are
+following these standards by utilizing this sample SplClassLoader
+implementation which is able to load PHP 5.3 classes.
+
+Example Implementation
+----------------------
+
+Below is an example function to simply demonstrate how the above
+proposed standards are autoloaded.
+
+```php
+<?php
+
+function autoload($className)
+{
+    $className = ltrim($className, '\\');
+    $fileName  = '';
+    $namespace = '';
+    if ($lastNsPos = strrpos($className, '\\')) {
+        $namespace = substr($className, 0, $lastNsPos);
+        $className = substr($className, $lastNsPos + 1);
+        $fileName  = str_replace('\\', DIRECTORY_SEPARATOR, $namespace) . DIRECTORY_SEPARATOR;
+    }
+    $fileName .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php';
+
+    require $fileName;
+}
+```
+
+SplClassLoader Implementation
+-----------------------------
+
+The following gist is a sample SplClassLoader implementation that can
+load your classes if you follow the autoloader interoperability
+standards proposed above. It is the current recommended way to load PHP
+5.3 classes that follow these standards.