public static function auto_load($class)
	{
		if (class_exists($class, FALSE))
			return TRUE;

		if (($suffix = strrpos($class, '_')) > 0)
		{
			// Find the class suffix
			$suffix = substr($class, $suffix + 1);
		}
		else
		{
			// No suffix
			$suffix = FALSE;
		}

		if ($suffix === 'Core')
		{
			$type = 'libraries';
			$file = substr($class, 0, -5);
		}
		elseif ($suffix === 'Controller')
		{
			$type = 'controllers';
			// Lowercase filename
			$file = strtolower(substr($class, 0, -11));
		}
		elseif ($suffix === 'Model')
		{
			$type = 'models';
			// Lowercase filename
			$file = strtolower(substr($class, 0, -6));
		}
		elseif ($suffix === 'Driver')
		{
			$type = 'libraries/drivers';
			$file = str_replace('_', '/', substr($class, 0, -7));
		}
		else
		{
			// This could be either a library or a helper, but libraries must
			// always be capitalized, so we check if the first character is
			// uppercase. If it is, we are loading a library, not a helper.
			$type = ($class[0] < 'a') ? 'libraries' : 'helpers';
			$file = $class;
		}

		if ($filename = self::find_file($type, $file))
		{
			// Load the class
			require $filename;
		}
		elseif ($type == 'controllers' && $filename = self::find_file($type, Router::$segments[0].'/'.$file))
		{
			// Load the class from a controllers subfolder
			require $filename;
		}
		else
		{
			// The class could not be found
			return FALSE;
		}

		if ($filename = self::find_file($type, self::$configuration['core']['extension_prefix'].$class))
		{
			// Load the class extension
			require $filename;
		}
		elseif ($suffix !== 'Core' AND class_exists($class.'_Core', FALSE))
		{
			// Class extension to be evaluated
			$extension = 'class '.$class.' extends '.$class.'_Core { }';

			// Start class analysis
			$core = new ReflectionClass($class.'_Core');

			if ($core->isAbstract())
			{
				// Make the extension abstract
				$extension = 'abstract '.$extension;
			}

			// Transparent class extensions are handled using eval. This is
			// a disgusting hack, but it gets the job done.
			eval($extension);
		}

		return TRUE;
	}

Kohana final class

php

PHP