replaces tabs in source code with regular spaces, added example for working with global variables

30 files changed, 748 insertions, 481 deletions

diff --git a/Examples/CallPhpFunctions/callphpfunction.cpp b/Examples/CallPhpFunctions/callphpfunction.cpp
index 8f212f8..9932a3e 100644
--- a/Examples/CallPhpFunctions/callphpfunction.cpp
+++ b/Examples/CallPhpFunctions/callphpfunction.cpp
@@ -1,12 +1,12 @@
 /**
- *	callphpfunction.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  callphpfunction.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a php function call in C++.
+ *  An example file to show the working of a php function call in C++.
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <iostream>
 #include <phpcpp.h>
@@ -17,37 +17,37 @@
 using namespace std;
 
 /**
- * 	call_php_function()
- * 	Calls a function in PHP space.
- * 	@param		&params
- * 	@return		Php::Value
+ *  call_php_function()
+ *  Calls a function in PHP space.
+ *  @param      &params
+ *  @return     Php::Value
  */
 Php::Value call_php_function(Php::Parameters &params)
 {
-	// check whether the parameter is callable
-	if (!params[0].isCallable()) throw Php::Exception("Not a callable type.");
-		
-	// perform the callback
-	return params[0](1,2,3);
+    // check whether the parameter is callable
+    if (!params[0].isCallable()) throw Php::Exception("Not a callable type.");
+        
+    // perform the callback
+    return params[0](1,2,3);
 }
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("call_php_function","1.0");
         
         // add function to extension
         extension.add("call_php_function", call_php_function, {
-			Php::ByVal("addFunc", Php::callableType),
-			Php::ByVal("x", Php::numericType)
-			});
-		
-		// return the extension module
-		return extension.module();
-	}
+            Php::ByVal("addFunc", Php::callableType),
+            Php::ByVal("x", Php::numericType)
+            });
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/CallPhpFunctions/callphpfunction.php b/Examples/CallPhpFunctions/callphpfunction.php
index 77d633c..8da284d 100644
--- a/Examples/CallPhpFunctions/callphpfunction.php
+++ b/Examples/CallPhpFunctions/callphpfunction.php
@@ -1,33 +1,33 @@
 <?php
 /**
- *	callphpfunction.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  callphpfunction.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a php function call in C++.
+ *  An example file to show the working of a php function call in C++.
  */
 
 class MyClass
 {
-	function method($a,$b,$c)
-	{
-		return $a+$b+$c;
-	}
+    function method($a,$b,$c)
+    {
+        return $a+$b+$c;
+    }
 }
 
 function myFunction($a,$b,$c)
 {
-	return $a+$b+$c;
+    return $a+$b+$c;
 }
 
 /**
- * 	Call a C++ function with a callable PHP function as its parameter.
- * 	The PHP function is then executed from the C++ code.
- * 	The PHP function is this case, adds three numbers.
+ *  Call a C++ function with a callable PHP function as its parameter.
+ *  The PHP function is then executed from the C++ code.
+ *  The PHP function is this case, adds three numbers.
  */
 echo(call_php_function(function($a, $b, $c){
-								return $a + $b + $c;
-							})."\n");
-							
+                                return $a + $b + $c;
+                            })."\n");
+                            
 echo(call_php_function("myFunction")."\n");
-							
+                            
 echo(call_php_function(array(new MyClass(), 'method'))."\n");
diff --git a/Examples/CppClassesInPhp/cppclassinphp.cpp b/Examples/CppClassesInPhp/cppclassinphp.cpp
index fffa655..2894fdc 100644
--- a/Examples/CppClassesInPhp/cppclassinphp.cpp
+++ b/Examples/CppClassesInPhp/cppclassinphp.cpp
@@ -1,8 +1,8 @@
 /**
- *	cppclassinphp.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  cppclassinphp.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of using a C++ class in PHP.
+ *  An example file to show the working of using a C++ class in PHP.
  */
 
 #include "includeMyCustomClass.h"
@@ -40,32 +40,32 @@ public:
     }
     
     void myMethod(Php::Parameters &params)
-	{
-		std::cout << "myMethod is called." << std::endl;
-		std::cout << "_x: " << _x << std::endl;
-		_x = params[0];
-		std::cout << "New _x" << _x << std::endl;
-	}
+    {
+        std::cout << "myMethod is called." << std::endl;
+        std::cout << "_x: " << _x << std::endl;
+        _x = params[0];
+        std::cout << "New _x" << _x << std::endl;
+    }
 };
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_function_with_parameters","1.0");
         
         // add the custom class ot the extension
-		extension.add("MyClass", Php::Class<MyCustomClass>({
-			Php::Public("myMethod", Php::Method<MyCustomClass>(&MyCustomClass::myMethod),{
-				Php::ByVal("newX", Php::numericType)
-				})
-			}));
-				
-		// return the extension module
-		return extension.module();
-	}
+        extension.add("MyClass", Php::Class<MyCustomClass>({
+            Php::Public("myMethod", Php::Method<MyCustomClass>(&MyCustomClass::myMethod),{
+                Php::ByVal("newX", Php::numericType)
+                })
+            }));
+                
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/CppClassesInPhp/cppclassinphp.php b/Examples/CppClassesInPhp/cppclassinphp.php
index bea276c..1eccf95 100644
--- a/Examples/CppClassesInPhp/cppclassinphp.php
+++ b/Examples/CppClassesInPhp/cppclassinphp.php
@@ -1,9 +1,9 @@
 <?php
 /**
- *	cppclassinphp.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  cppclassinphp.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of using a C++ class in PHP.
+ *  An example file to show the working of using a C++ class in PHP.
  */
 
 //create a MyCustomClass object, which is an object of a C++ class
diff --git a/Examples/Exceptions/ExceptionCatch/exception.php b/Examples/Exceptions/ExceptionCatch/exception.php
index 06bd534..0fec704 100644
--- a/Examples/Exceptions/ExceptionCatch/exception.php
+++ b/Examples/Exceptions/ExceptionCatch/exception.php
@@ -1,12 +1,12 @@
 <?php
 /**
- *	exception.cpp
+ *  exception.cpp
  * 
- * 	@author Jasper van Eck <jasper.vaneck@copernica.com>
+ *  @author Jasper van Eck <jasper.vaneck@copernica.com>
  * 
- * 	This example shows the working of a C++ function that throws an 
- * 	exception, and that exception is then caught by PHP code.
- * 	
+ *  This example shows the working of a C++ function that throws an 
+ *  exception, and that exception is then caught by PHP code.
+ *  
  */
 
 // call the second C++ function that accepts a callback
diff --git a/Examples/Exceptions/ExceptionCatch/exceptionCatch.cpp b/Examples/Exceptions/ExceptionCatch/exceptionCatch.cpp
index 1b95277..a5f7b96 100644
--- a/Examples/Exceptions/ExceptionCatch/exceptionCatch.cpp
+++ b/Examples/Exceptions/ExceptionCatch/exceptionCatch.cpp
@@ -1,14 +1,14 @@
 /**
- *	exception.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  exception.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a C++ function that 
- * 	takes a callback function as parameter, and handles the 
- * 	exception thrown by the callback function.
+ *  An example file to show the working of a C++ function that 
+ *  takes a callback function as parameter, and handles the 
+ *  exception thrown by the callback function.
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <phpcpp.h>
 
@@ -18,9 +18,9 @@
 using namespace std;
 
 /**
- * 	my_catch_exception_function()
- * 	Catches the exception thrown by the PHP callback function.
- * 	@param		Php::Parameters
+ *  my_catch_exception_function()
+ *  Catches the exception thrown by the PHP callback function.
+ *  @param      Php::Parameters
  */
 void my_catch_exception_function(Php::Parameters &params)
 {
@@ -47,18 +47,18 @@ void my_catch_exception_function(Php::Parameters &params)
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_exception_catch","1.0");
         
         // add function to extension
         extension.add("my_catch_exception_function", my_catch_exception_function, {
-			Php::ByVal("callback", Php::callableType);
-			});
-		
-		// return the extension module
-		return extension.module();
-	}
+            Php::ByVal("callback", Php::callableType);
+            });
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/Exceptions/ExceptionThrow/exception.php b/Examples/Exceptions/ExceptionThrow/exception.php
index 81bbd50..3afe86f 100644
--- a/Examples/Exceptions/ExceptionThrow/exception.php
+++ b/Examples/Exceptions/ExceptionThrow/exception.php
@@ -1,25 +1,25 @@
 <?php
 /**
- *	exception.cpp
+ *  exception.cpp
  * 
- * 	@author Jasper van Eck <jasper.vaneck@copernica.com>
+ *  @author Jasper van Eck <jasper.vaneck@copernica.com>
  * 
- * 	This example shows the working of a C++ function that throws an 
- * 	exception, and that exception is then caught by PHP code.
- * 	
+ *  This example shows the working of a C++ function that throws an 
+ *  exception, and that exception is then caught by PHP code.
+ *  
  */
 
 // try-catch block to be able to handle the exception
 try
 {
-	// the my_throw_exception function is implemented in C++. and
-	// it is going to throw an exception
-	my_throw_exception_function();
+    // the my_throw_exception function is implemented in C++. and
+    // it is going to throw an exception
+    my_throw_exception_function();
 }
 catch (Exception $exception)
 {
-	// the exception object is thrown by C++ code, and caught by PHP
-	// code
-	echo $exception->getMessage(). "\n";
-	
+    // the exception object is thrown by C++ code, and caught by PHP
+    // code
+    echo $exception->getMessage(). "\n";
+    
 }
diff --git a/Examples/Exceptions/ExceptionThrow/exceptionThrow.cpp b/Examples/Exceptions/ExceptionThrow/exceptionThrow.cpp
index 3719e6f..d104047 100644
--- a/Examples/Exceptions/ExceptionThrow/exceptionThrow.cpp
+++ b/Examples/Exceptions/ExceptionThrow/exceptionThrow.cpp
@@ -1,14 +1,14 @@
 /**
- *	exception.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  exception.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a C++ function that 
- * 	throws an exception, which can be caught by PHP.
- * 	
+ *  An example file to show the working of a C++ function that 
+ *  throws an exception, which can be caught by PHP.
+ *  
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <phpcpp.h>
 
@@ -18,28 +18,28 @@
 using namespace std;
 
 /**
- * 	my_throw_exception_function()
- * 	Throws an exception which should be caught by PHP.
+ *  my_throw_exception_function()
+ *  Throws an exception which should be caught by PHP.
  */
 void my_throw_exception_function()
 {
-	throw Php::Exception("I threw an exception in my_throw_exception_function()");
+    throw Php::Exception("I threw an exception in my_throw_exception_function()");
 }
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_exception_throw","1.0");
         
         // add function to extension
         extension.add("my_throw_exception_function", my_throw_exception_function);
-		
-		// return the extension module
-		return extension.module();
-	}
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/Extension/extension.cpp b/Examples/Extension/extension.cpp
index 9f7f495..99da5c7 100644
--- a/Examples/Extension/extension.cpp
+++ b/Examples/Extension/extension.cpp
@@ -1,8 +1,8 @@
 /**
- *	extension.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  extension.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of an extension.
+ *  An example file to show the working of an extension.
  */
 // library include
 #include <phpcpp.h>
@@ -15,13 +15,13 @@ using namespace std;
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_simple_extension","1.0");
-		
-		// return the extension module
-		return extension.module();
-	}
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/Extension/extension.php b/Examples/Extension/extension.php
index 3941c8c..6f6b03c 100644
--- a/Examples/Extension/extension.php
+++ b/Examples/Extension/extension.php
@@ -1,9 +1,9 @@
 <?php
 /*
- *	extension.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  extension.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of an extension.
+ *  An example file to show the working of an extension.
  */
 
 // print all the extensions currently loaded.
diff --git a/Examples/FunctionNoParameters/functionnoparameters.cpp b/Examples/FunctionNoParameters/functionnoparameters.cpp
index da645fd..8934169 100644
--- a/Examples/FunctionNoParameters/functionnoparameters.cpp
+++ b/Examples/FunctionNoParameters/functionnoparameters.cpp
@@ -1,12 +1,12 @@
 /**
- *	functionnoparameters.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionnoparameters.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call without parameters.
+ *  An example file to show the working of a function call without parameters.
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <phpcpp.h>
 
@@ -16,28 +16,28 @@
 using namespace std;
 
 /**
- * 	my_no_parameters_function()
- * 	@return Php::Value
+ *  my_no_parameters_function()
+ *  @return Php::Value
  */
 Php::Value my_no_parameters_function()
 {
-	return "42";
+    return "42";
 }
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_function_return_value","1.0");
         
         // add function to extension
         extension.add("my_no_parameters_function", my_no_parameters_function);
-		
-		// return the extension module
-		return extension.module();
-	}
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/FunctionNoParameters/functionnoparameters.php b/Examples/FunctionNoParameters/functionnoparameters.php
index f4035ae..9c62845 100644
--- a/Examples/FunctionNoParameters/functionnoparameters.php
+++ b/Examples/FunctionNoParameters/functionnoparameters.php
@@ -1,9 +1,9 @@
 <?php
 /**
- *	functionnoparameters.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionnoparameters.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call without parameters.
+ *  An example file to show the working of a function call without parameters.
  */
 
 
diff --git a/Examples/FunctionReturnValue/functionreturnvalue.cpp b/Examples/FunctionReturnValue/functionreturnvalue.cpp
index 890a15f..a107fe7 100644
--- a/Examples/FunctionReturnValue/functionreturnvalue.cpp
+++ b/Examples/FunctionReturnValue/functionreturnvalue.cpp
@@ -1,12 +1,12 @@
 /**
- *	functionreturnvalue.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionreturnvalue.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call with a return value.
+ *  An example file to show the working of a function call with a return value.
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <phpcpp.h>
 
@@ -16,28 +16,28 @@
 using namespace std;
 
 /**
- * 	my_return_value_function()
- * 	@return Php::Value
+ *  my_return_value_function()
+ *  @return Php::Value
  */
 Php::Value my_return_value_function()
 {
-	return "42";
+    return "42";
 }
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_function_return_value","1.0");
         
         // add function to extension
         extension.add("my_return_value_function", my_return_value_function);
-		
-		// return the extension module
-		return extension.module();
-	}
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/FunctionReturnValue/functionreturnvalue.php b/Examples/FunctionReturnValue/functionreturnvalue.php
index 1626e19..dc3e68e 100644
--- a/Examples/FunctionReturnValue/functionreturnvalue.php
+++ b/Examples/FunctionReturnValue/functionreturnvalue.php
@@ -1,12 +1,12 @@
 <?php
 /**
- *	functionreturnvalue.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionreturnvalue.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call with a return value.
+ *  An example file to show the working of a function call with a return value.
  */
 
 /**
- *	Run a function which returns a value.
+ *  Run a function which returns a value.
  */
 echo my_return_value_function() . "\n";
diff --git a/Examples/FunctionVoid/functionvoid.cpp b/Examples/FunctionVoid/functionvoid.cpp
index f4386ea..91b7bb3 100644
--- a/Examples/FunctionVoid/functionvoid.cpp
+++ b/Examples/FunctionVoid/functionvoid.cpp
@@ -1,12 +1,12 @@
 /**
- *	functionvoid.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionvoid.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a void function call.
+ *  An example file to show the working of a void function call.
  */
 
 /**
- * 	Libraries used.
+ *  Libraries used.
  */
 #include <iostream>
 #include <phpcpp.h>
@@ -17,27 +17,27 @@
 using namespace std;
 
 /**
- * 	my_function_void()
+ *  my_function_void()
  */
 void my_function_void()
 {
-	cout << "In my_function_void()" << endl;
+    cout << "In my_function_void()" << endl;
 }
 
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_function_void","1.0");
         
         // add function to extension
         extension.add("my_void_function", my_function_void);
-		
-		// return the extension module
-		return extension.module();
-	}
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/FunctionVoid/functionvoid.php b/Examples/FunctionVoid/functionvoid.php
index e6fbb67..d057f92 100644
--- a/Examples/FunctionVoid/functionvoid.php
+++ b/Examples/FunctionVoid/functionvoid.php
@@ -1,13 +1,13 @@
 <?php
 /*
- *	functionvoid.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionvoid.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a void function call.
+ *  An example file to show the working of a void function call.
  */
 
 /*
- *	Run the function with the given name. As you can see, the given name 
- * 	can be different from the actual function name.
+ *  Run the function with the given name. As you can see, the given name 
+ *  can be different from the actual function name.
  */
 my_void_function();
diff --git a/Examples/FunctionWithParameters/functionwithparameters.cpp b/Examples/FunctionWithParameters/functionwithparameters.cpp
index 4f70f26..dd7bb9f 100644
--- a/Examples/FunctionWithParameters/functionwithparameters.cpp
+++ b/Examples/FunctionWithParameters/functionwithparameters.cpp
@@ -1,19 +1,19 @@
 /**
- *	functionwithparameters.cpp
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionwithparameters.cpp
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call with parameters.
+ *  An example file to show the working of a function call with parameters.
  */
 
 /**
- * 	Default Cpp libraries
+ *  Default Cpp libraries
  */
  
 #include <string>
 #include <iostream>
 
 /**
- * 	Our own library.
+ *  Our own library.
  */
 #include <phpcpp.h>
 
@@ -23,102 +23,102 @@
 using namespace std;
 
 /**
- * 	my_with_undefined_parameters_function()
- * 	@param	Php:Parameters	the given parameters
+ *  my_with_undefined_parameters_function()
+ *  @param  Php:Parameters  the given parameters
  */
 void my_with_undefined_parameters_function(Php::Parameters &params)
 {
-	for (unsigned int i = 0; i < params.size(); i++)
-	{
-		cout << "Parameter " << i << ": " << params[i] << endl;
-	}
+    for (unsigned int i = 0; i < params.size(); i++)
+    {
+        cout << "Parameter " << i << ": " << params[i] << endl;
+    }
 }
 
 /**
- * 	my_with_defined_parameters_function()
- * 	@param	Php::Parameters		the given parameters
- * 	@return Php::Value			Param[0] and Param[1] added
+ *  my_with_defined_parameters_function()
+ *  @param  Php::Parameters     the given parameters
+ *  @return Php::Value          Param[0] and Param[1] added
  */
 Php::Value my_with_defined_parameters_function(Php::Parameters &params)
 {
-	for (unsigned int i = 0; i < params.size(); i++)
-	{
-		cout << "Parameter " << i << ": " << params[i] << endl;
-	}
-	
-	return params[0] + params[1];
+    for (unsigned int i = 0; i < params.size(); i++)
+    {
+        cout << "Parameter " << i << ": " << params[i] << endl;
+    }
+    
+    return params[0] + params[1];
 }
 
 /**
- * 	This functions receives a reference to a variable. When the variable is altered,
- * 	so is the value in the php script.
- * 	my_with_defined_parameters_reference_function()
- * 	@param	Php::Parameters		the given parameters
+ *  This functions receives a reference to a variable. When the variable is altered,
+ *  so is the value in the php script.
+ *  my_with_defined_parameters_reference_function()
+ *  @param  Php::Parameters     the given parameters
  */
 void my_with_defined_parameters_reference_function(Php::Parameters &params)
 {
-	params[0] = "I changed!";
+    params[0] = "I changed!";
 }
 
 /**
- * 	my_with_defined_parameters_reference_function()
- * 	@param	Php::Parameters		the given parameters
+ *  my_with_defined_parameters_reference_function()
+ *  @param  Php::Parameters     the given parameters
  */
 void my_with_defined_array_parameters_function(Php::Parameters &params)
 {
-	for (int i = 0; i < params[0].size(); i++)
-	{
-		cout << "The array: " << params[0][i] << endl;
-	}
+    for (int i = 0; i < params[0].size(); i++)
+    {
+        cout << "The array: " << params[0][i] << endl;
+    }
 }
 
 /**
- * 	my_with_defined_object_parameters_function()
+ *  my_with_defined_object_parameters_function()
  *  The use of objects is not yet implemented.
- * 	@param Php::Parameters		the given parameters
+ *  @param Php::Parameters      the given parameters
  */
 void my_with_defined_object_parameters_function(Php::Parameters &params)
 {
-	for (unsigned int i = 0; i < params.size(); i++)
-	{
-		cout << params[i] << endl;
-	}
+    for (unsigned int i = 0; i < params.size(); i++)
+    {
+        cout << params[i] << endl;
+    }
 }
 
 // Symbols are exported according to the "C" language
 extern "C" 
 {
-	// export the "get_module" function that will be called by the Zend engine
-	PHPCPP_EXPORT void *get_module()
-	{
-		// create extension
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
         static Php::Extension extension("my_function_with_parameters","1.0");
         
         // add function, with undefined parameters, to extension
         extension.add("my_with_undefined_parameters_function", my_with_undefined_parameters_function);
-		
-		// add function, with defined numeric parameters, to extension
-		extension.add("my_with_defined_parameters_function", my_with_defined_parameters_function, {
-			Php::ByVal("x", Php::numericType),
+        
+        // add function, with defined numeric parameters, to extension
+        extension.add("my_with_defined_parameters_function", my_with_defined_parameters_function, {
+            Php::ByVal("x", Php::numericType),
             Php::ByVal("y", Php::numericType)
-			});
-		
-		// add function, with defined parameter by reference, to extension
-		extension.add("my_with_defined_parameters_reference_function", my_with_defined_parameters_reference_function, {
-			Php::ByRef("string", Php::stringType)
-			});
-		
-		// add function, with defined array parameter, to extension
-		extension.add("my_with_defined_array_parameters_function", my_with_defined_array_parameters_function, {
-			Php::ByVal("array", Php::arrayType)
-			});
-		
-		// add function, with defined object parameter, to extension
-		extension.add("my_with_defined_object_parameters_function", my_with_defined_object_parameters_function, {
-			Php::ByVal("myClassObjVar", "MyPhpClass")
-			});
-		
-		// return the extension module
-		return extension.module();
-	}
+            });
+        
+        // add function, with defined parameter by reference, to extension
+        extension.add("my_with_defined_parameters_reference_function", my_with_defined_parameters_reference_function, {
+            Php::ByRef("string", Php::stringType)
+            });
+        
+        // add function, with defined array parameter, to extension
+        extension.add("my_with_defined_array_parameters_function", my_with_defined_array_parameters_function, {
+            Php::ByVal("array", Php::arrayType)
+            });
+        
+        // add function, with defined object parameter, to extension
+        extension.add("my_with_defined_object_parameters_function", my_with_defined_object_parameters_function, {
+            Php::ByVal("myClassObjVar", "MyPhpClass")
+            });
+        
+        // return the extension module
+        return extension.module();
+    }
 }
diff --git a/Examples/FunctionWithParameters/functionwithparameters.php b/Examples/FunctionWithParameters/functionwithparameters.php
index 0ca360e..b1c3198 100644
--- a/Examples/FunctionWithParameters/functionwithparameters.php
+++ b/Examples/FunctionWithParameters/functionwithparameters.php
@@ -1,17 +1,17 @@
 <?php
 /*
- *	functionwithparameters.php
- * 	@author Jasper van Eck<jasper.vaneck@copernica.com>
+ *  functionwithparameters.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
  * 
- * 	An example file to show the working of a function call with parameters, defined and undefined.
+ *  An example file to show the working of a function call with parameters, defined and undefined.
  */
 
 /*
- * 	Test class.
+ *  Test class.
  */
 class MyPhpClass {
 
-	public $aMemberVar = "aMemberVar";
+    public $aMemberVar = "aMemberVar";
 
     public function __toString()
     {
@@ -20,12 +20,12 @@ class MyPhpClass {
     
     public function getMemberVar()
     {
-		return $aMemberVar;
-	}
+        return $aMemberVar;
+    }
 }
 
 /*
- *	Run a function with parameters. 
+ *  Run a function with parameters. 
  */
  
 
@@ -33,20 +33,20 @@ class MyPhpClass {
  * A function which takes parameters, which are all undefined;
  * my_with_undefined_parameters_function('1st','2nd','3rd','4th')
  */
-echo 	my_with_undefined_parameters_function('1st','2nd','3rd','4th') . "\n\n\n";
+echo    my_with_undefined_parameters_function('1st','2nd','3rd','4th') . "\n\n\n";
 
 /*
  * A function which takes parameters, which are all defined;
  * my_with_defined_parameters_function(21,42)
  */
-		
-echo 	my_with_defined_parameters_function(21,42) . "\n\n\n";
+        
+echo    my_with_defined_parameters_function(21,42) . "\n\n\n";
 
 /* 
  * A function which takes a reference of a parameter
  * my_with_defined_parameters_reference_function(referenceVar)
  */
-	
+    
 $referenceVar = "I am unchanged.";
 echo "The value of referenceVar: " . $referenceVar. "\n";
 
@@ -65,9 +65,9 @@ echo my_with_defined_array_parameters_function($myArray) . "\n\n\n";
  * A function which takes an object as a parameter
  * my_with_defined_object_parameter_function(myPhpClass)
  */
-		
+        
 $myPhpClass = new MyPhpClass;
-echo 	my_with_defined_object_parameters_function($myPhpClass);
+echo    my_with_defined_object_parameters_function($myPhpClass);
 
 /*
  * Accessing a non-existant parameters index will result in a segmentation fault.
diff --git a/Examples/Globals/globals.cpp b/Examples/Globals/globals.cpp
new file mode 100644
index 0000000..6fa9eea
--- /dev/null
+++ b/Examples/Globals/globals.cpp
@@ -0,0 +1,60 @@
+/**
+ *  functionvoid.cpp
+ *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
+ * 
+ *  An example file to show how global variables can be accessed
+ */
+
+/**
+ *  Libraries used.
+ */
+#include <iostream>
+#include <phpcpp.h>
+
+/**
+ *  Namespace to use
+ */
+using namespace std;
+
+/**
+ *  process_globals()
+ * 
+ *  This function reads and modifies global variables
+ */
+Php::Value process_globals()
+{
+    // all global variables can be accessed via the Php::globals variable,
+    // which is more or less the same as the PHP $_GLOBALS variable
+    
+    // set a global variable
+    Php::globals["a"] = 1;
+    
+    // increment a global variable
+    Php::globals["b"] += 1;
+    
+    // set a global variable to be an array
+    Php::globals["c"] = Php::Array();
+    
+    // add a member to an array
+    Php::globals["c"]["member"] = 123;
+    
+    // if a global variable holds a function, we can call it
+    return Php::globals["d"](1,2,3);
+}
+
+// Symbols are exported according to the "C" language
+extern "C" 
+{
+    // export the "get_module" function that will be called by the Zend engine
+    PHPCPP_EXPORT void *get_module()
+    {
+        // create extension
+        static Php::Extension extension("globals","1.0");
+        
+        // add function to extension
+        extension.add("process_globals", process_globals);
+        
+        // return the extension module
+        return extension.module();
+    }
+}
diff --git a/Examples/Globals/globals.php b/Examples/Globals/globals.php
new file mode 100644
index 0000000..36febf6
--- /dev/null
+++ b/Examples/Globals/globals.php
@@ -0,0 +1,29 @@
+<?php
+/*
+ *  globals.php
+ *  @author Jasper van Eck<jasper.vaneck@copernica.com>
+ * 
+ *  An example file to show the working of a void function call.
+ */
+
+// we first need to set a number of globals
+$b = 10;
+$d = function($a,$b,$c) {
+    return $a+$b+$c;
+};
+
+// call the C++ function that will do something
+$d = process_globals();
+
+// the global variable $a should not have the value 1
+echo("a = $a\n");
+
+// the variable $b should not be 11
+echo("b = $b\n");
+
+// $c should be an array
+echo("c['member'] = ".$c['member']."\n");
+
+// $d is overwritten and now is 6
+echo("d = $d\n");
+
diff --git a/Examples/README.md b/Examples/README.md
index 5bd9e1e..d29673a 100644
--- a/Examples/README.md
+++ b/Examples/README.md
@@ -1,148 +1,160 @@
 This directory contains a number of examples that show how to use the
 PHP-CPP library. 
 
-To run an example, there are several steps which need to be taken. 
+To run an example, there are a couple of steps that need to be taken. 
 The first step is compiling and installing the PHPCPP library. This is
-done running 'make' and then 'make install' in the main directory.
-The second step is compiling the C++ code and made into an extension 
-usable by PHP. This is done by running 'make' and 'make install' 
-in an Example directory. Do make sure you've edited the Makefile
-according to your own specific directories.
+done by running 'make' and then 'make install' in the main directory.
+
+The second step is to compile the C++ code of an example and make it 
+into an extension usable by PHP. This is done by running 'make' and 
+'make install' in an Example directory. Do make sure you've edited the 
+Makefile according to your own specific directories.
 
 The following examples are available:
 
 
 ### [Extension](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/Extension)
 
-	The first example does nothing - it only shows how to create your
-	own extension. This means your extension will be listed in the 
-	output of "phpinfo()", and it is included in the array returned 
-	by theget_loaded_modules() function.
-	
-	There are no functions or classes defined by this first example
-	extension.
-	
-	
+    The first example does nothing - it only shows how to create your
+    own extension. This means your extension will be listed in the 
+    output of "phpinfo()", and it is included in the array returned 
+    by theget_loaded_modules() function.
+    
+    There are no functions or classes defined by this first example
+    extension.
+    
+    
 ### [FunctionVoid](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/FunctionVoid)
 
-	This second example shows how to add a function to the extension 
-	and call that function from the PHP code. Adding a function to 
-	your extension means that you can call it anywhere from the PHP 
-	code.
-	
-	Furthermore, it is possible to associate your C++ function with 
-	another name. This other name is then used in PHP to call the C++ 
-	function, rather than the original C++ function name.
-	
-	Functions and/or classes defined in this example.
-		- void my_function_void() Named as my_void_function()
+    This second example shows how to add a function to the extension 
+    and call that function from the PHP code. Adding a function to 
+    your extension means that you can call it anywhere from the PHP 
+    code.
+    
+    Furthermore, it is possible to associate your C++ function with 
+    another name. This other name is then used in PHP to call the C++ 
+    function, rather than the original C++ function name.
+    
+    Functions and/or classes defined in this example.
+        - void my_function_void() Named as my_void_function()
 
 
 ### [FunctionReturnValue](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/FunctionReturnValue)
 
-	The third example shows how to return a value from C++ to PHP. 
-	Virtually any type of value can be returned to PHP from C++.
-	The returned value must be returned as Php::Value, rather than
-	its own type. This Php::Value can then be used in your PHP code.
-	
-	Because a Php::Value is always returned, there is no need to specify
-	the return type of the function when adding it to your extension.
-	
-	Functions and/or classes defined in this example.
-		- Php::Value my_return_value_function()
-		
+    The third example shows how to return a value from C++ to PHP. 
+    Virtually any type of value can be returned to PHP from C++.
+    The returned value must be returned as Php::Value object, rather 
+    than a native C/C++ type. This Php::Value class takes care of
+    converting native values into values usable in your PHP code.
+    
+    Because a Php::Value is always returned, there is no need to specify
+    the return type of the function when adding it to your extension.
+    
+    Functions and/or classes defined in this example.
+        - Php::Value my_return_value_function()
+        
 
 ### [FunctionNoParameters](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/FunctionNoParameters)
 
-	The fourth example is a combination of the second and third example.
-	This example illustrates how to call a function without parameters.
-	The function is added to your extension, and can then be called from
-	your PHP script.
-	
-	The function returns a Php::Value to show that the call succeeded.
-	
-	Functions and/or classes defined in this example.
-		- Php::Value my_no_parameters_function()
-	
-	
+    The fourth example is a combination of the second and third example.
+    This example illustrates how to call a function without parameters.
+    The function is added to your extension, and can then be called from
+    your PHP script.
+    
+    The function returns a Php::Value to show that the call succeeded.
+    
+    Functions and/or classes defined in this example.
+        - Php::Value my_no_parameters_function()
+    
+    
 ### [FunctionWithParameters](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/FunctionWithParameters)
 
-	The fifth example is an example to show how several different types
-	of parameters can used for functions. There are two ways to pass a 
-	parameter, by value(Php::ByVal) and by reference(Php::ByRef). Each 
-	take two parameters of their own. The first being the parameter name,
-	and the second the parameter type.
-	
-	Furthermore, parameters are always stored in the Php::Parameters 
-	object. This object is basicly an array which hold all the parameters,
-	in order.
-	
-	The first option being the undefined parameters. With undefined 
-	parameters, we can pass any and as many parameters as we want to 
-	the function. 
-	
-	The second option is defining each parameter when adding the function
-	to your extension. In this case we have added two Php::numericType
-	parameters to the function. In 'type.h' you can find all avaiable
-	types, however not every type has been implemented yet.
-	
-	The third option is passing a reference of a variable. Meaning when
-	it is altered in the C++ code, its value will also change in the PHP
-	code. This can achieved by using Php:ByRef, rather than Php::ByVal.
-	
-	The fourth option is passing an array as parameter. The array 
-	parameter will be accessible from the N-1 index of the 
-	Php::Parameters object, where is the argument number of the array
-	when passing it to the function.
-	
-	The fifth and final option is passing an object. An object can be 
-	passed in the same way as any other data type, except for that 
-	you must specify what the class is of the object. This can be done
-	by passing a string with the class name as the second parameter to 
-	Php::ByVal or Php::ByRef.
-	
-	Functions and/or classes defined in this example.
-		1. void my_with_undefined_parameters_function(Php::Parameters &params)
-		2. Php::Value my_with_defined_parameters_function(Php::Parameters &params)
-		3. void my_with_defined_parameters_reference_function(Php::Parameters &params)
-		4. void my_with_defined_array_parameters_function(Php::Parameters &params)
-		5. void my_with_defined_object_parameters_function(Php::Parameters &params)
+    The fifth example is an example to show how several different types
+    of parameters can used for functions. There are two ways to pass a 
+    parameter, by value(Php::ByVal) and by reference(Php::ByRef). Each 
+    take two parameters of their own. The first being the parameter name,
+    and the second the parameter type.
+    
+    Furthermore, parameters are always stored in the Php::Parameters 
+    object. This object is basicly an array which hold all the parameters,
+    in order.
+    
+    The first option being the undefined parameters. With undefined 
+    parameters, we can pass any and as many parameters as we want to 
+    the function. 
+    
+    The second option is defining each parameter when adding the function
+    to your extension. In this case we have added two Php::numericType
+    parameters to the function. In 'type.h' you can find all avaiable
+    types, however not every type has been implemented yet.
+    
+    The third option is passing a reference of a variable. Meaning when
+    it is altered in the C++ code, its value will also change in the PHP
+    code. This can achieved by using Php:ByRef, rather than Php::ByVal.
+    
+    The fourth option is passing an array as parameter. The array 
+    parameter will be accessible from the N-1 index of the 
+    Php::Parameters object, where is the argument number of the array
+    when passing it to the function.
+    
+    The fifth and final option is passing an object. An object can be 
+    passed in the same way as any other data type, except for that 
+    you must specify what the class is of the object. This can be done
+    by passing a string with the class name as the second parameter to 
+    Php::ByVal or Php::ByRef.
+    
+    Functions and/or classes defined in this example.
+        1. void my_with_undefined_parameters_function(Php::Parameters &params)
+        2. Php::Value my_with_defined_parameters_function(Php::Parameters &params)
+        3. void my_with_defined_parameters_reference_function(Php::Parameters &params)
+        4. void my_with_defined_array_parameters_function(Php::Parameters &params)
+        5. void my_with_defined_object_parameters_function(Php::Parameters &params)
+
+
+### [Globals](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/Globals)
+
+    Global PHP variables can be used accessed from your C++ code. You
+    can do this by accessing the Php::values array, which more or less
+    behaves the same as the $_GLOBALS array does in PHP.
+
+    Functions and/or classes defined in this example.
+        1. void process_globals()
 
 
 ### [Exceptions](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/Exceptions)
 
-	The sixth example is composed of two parts, the throw exception and 
-	the catch exception examples. The requirements of the catch example,
-	passing a callback as a parameter, have not yet been implemented. 
-	
-	The throw example is there to show that an exception thrown in
-	a C++ function can be caught and handled in your PHP script. The 
-	exception thrown is a Php::Exception.
-	
-	The catch example shows that when a PHP function is passed as a 
-	callback, and is capable of throwing a (PHP) exception, that it
-	can be caught as Php::Exception and then handled in the C++ code. 
-	However, the passing of a function as a callback has not yet been 
-	implemented. It would need to be implemented for this specific 
-	example to work.
-	
-	Functions and/or classes defined in this example.
-		- void my_catch_exception_function(Php::Parameters &params)
-		- void my_throw_exception_function()
+    The sixth example is composed of two parts, the throw exception and 
+    the catch exception examples. The requirements of the catch example,
+    passing a callback as a parameter, have not yet been implemented. 
+    
+    The throw example is there to show that an exception thrown in
+    a C++ function can be caught and handled in your PHP script. The 
+    exception thrown is a Php::Exception.
+    
+    The catch example shows that when a PHP function is passed as a 
+    callback, and is capable of throwing a (PHP) exception, that it
+    can be caught as Php::Exception and then handled in the C++ code. 
+    However, the passing of a function as a callback has not yet been 
+    implemented. It would need to be implemented for this specific 
+    example to work.
+    
+    Functions and/or classes defined in this example.
+        - void my_catch_exception_function(Php::Parameters &params)
+        - void my_throw_exception_function()
 
 
 ### [PHP function calls](https://github.com/EmielBruijntjes/PHP-CPP/tree/master/Examples/CallPhpFunctions)
 
-	The seventh example shows how to pass a callable PHP function as
-	a parameter. As can be seen in the example, there are several ways 
-	of passing a PHP function to the C++ function. When a function is 
-	passed, it is possible to use the () operator on the parameter, with 
-	the correct amount of parameters for the callable PHP function.
-	
-	When using the wrong amount, or when trying to use the () operator
-	on a non-callable type, you will get PHP errors rather than 
-	segmentation faults or other kinds of C++ errors.
-	
-	Functions and/or classes defined in this example.
-		- Php::Value call_php_function(Php::Parameters &params)
+    The seventh example shows how to pass a callable PHP function as
+    a parameter. As can be seen in the example, there are several ways 
+    of passing a PHP function to the C++ function. When a function is 
+    passed, it is possible to use the () operator on the parameter, with 
+    the correct amount of parameters for the callable PHP function.
+    
+    When using the wrong amount, or when trying to use the () operator
+    on a non-callable type, you will get PHP errors rather than 
+    segmentation faults or other kinds of C++ errors.
+    
+    Functions and/or classes defined in this example.
+        - Php::Value call_php_function(Php::Parameters &params)
 
diff --git a/documentation/tutorial.html b/documentation/tutorial.html
index 0e0a23e..30d8ea7 100644
--- a/documentation/tutorial.html
+++ b/documentation/tutorial.html
@@ -1,10 +1,28 @@
-<h1>Loading native extensions</h1>
+<div style="width: 1024px; font-family: verdana; font-size: 10pt; line-height: 16pt;">
+
+
+<h1>A PHP-CPP tutorial</h1>
 <p>
-    Native PHP extensions are compiled into *.so files, and can be enabled by adding 
-    a line to the core php.ini configuration file - or one of the additional 
-    configuration files that are loaded by PHP. If you do not know where you can 
-    find the PHP configuration file(s) on your system, you can run the following 
-    command from the command line:
+    Building PHP extensions with the PHP-CPP library is not at all difficult - 
+    in this tutorial we will give you step by step instructions to build
+    your own extensions. However, before we start the actual programming, we will
+    first explain how PHP interacts with its extensions - how extension libraries
+    are loaded and how PHP knows which functions, constants and classes are
+    defined by the extensions.
+</p>
+<h2>How does PHP load its extensions?</h2>
+<p>
+    You probably already know that native PHP extensions are compiled into *.so 
+    files on unix-like systems, and *.dll files on Windows environments, and that
+    the global php.ini file holds a list of all extensions available on your system.
+    This means that if you're building your own extension, you will also need to
+    create such a *.so or *.dll file and you will need to update the PHP 
+    configuration so that your own extension is loaded by PHP.
+</p>
+<h3>Where to find your PHP configuration files?</h3>
+<p>
+    If for one reason or another you can not find the PHP configuration file(s) 
+    on your system, you can run the following command from the command line:
 </p>
 <p>
     <code><pre>
@@ -12,6 +30,7 @@
     </pre></code>
 </p>
 <p>
+    This will output a list of all configuration files that are loaded by PHP.
     Extensions are enabled by adding "extension=name.so" lines to the
     configuration file - where 'name' should of course be replaced by the name of 
     your extension. A default PHP installation already comes with many default 
@@ -30,13 +49,16 @@
         php -i|grep extension_dir
     </pre></code>
 </p>
+<h2>The get_module() startup function</h2>
 <p>
-    When PHP starts, it loads its configuration file(s) and for each "extension=name.so"
-    line in it, it will open the appropriate library, and call the "get_module()"
-    function from it. Each extension library must therefore define and implement 
-    this "get_module()" C function. The function is called by PHP right after
-    the library is loaded (and thus way before pageviews are handled), and it 
-    should return a memory address that points to a structure that holds information 
+    Before we explain how you can create your own extension however, we first explain
+    what PHP does to load an extension. When PHP starts, it loads the configuration 
+    file(s) that we just described and for each "extension=name.so" line in these
+    files, it opens the appropriate library, and calls the "get_module()"
+    function from it. Each extension library (your extension too) must therefore 
+    define and implement this "get_module()" C function. The function is called by 
+    PHP right after the library is loaded (and thus way before pageviews are handled), 
+    and it should return a memory address that points to a structure that holds information 
     about all functions, classes, variables and constants that are made available 
     by the extension. 
 </p>
@@ -60,7 +82,9 @@
 </p>
 <p>
     In the example above you see a very straightforward implementation of the
-    get_module() function. A number of elements require special attention. For a 
+    get_module() function. Every PHP extension that uses the PHP-CPP library
+    implements this function in a more or less similar way as the extension 
+    starting point. A number of elements require special attention. For a 
     start, the only header file that you see is the phpcpp.h header
     file. If you're using the PHP-CPP library to build your own extensions,
     you do not have to include the complicated, unstructured, and mostly undocumented
@@ -69,8 +93,9 @@
     files of the core PHP engine - but you do not have to.
 </p>
 <p>
-    The PHP-CPP library is a C++ library, and you can use all features
-    of this language. However, PHP expects your library, and especially your 
+    The next thing that you'll notice it that we placed the get_module() function
+    inside an 'extern "C"' code block. As the name of the library already gives away, 
+    PHP-CPP is a C++ library. However, PHP expects your library, and especially your 
     get_module() function, to be implemented in C and not in C++. That's why we've 
     wrapped the get_module() function in an 'extern "C"' block. This will instruct 
     the C++ compiler that the get_module() is a regular C function, and
@@ -85,19 +110,19 @@
 <p>
     Inside the get_module() function the Extension object is instantiated, and the
     Extension::module() method is called. It is crucial that you make a <i>static</i>
-    instance of this Extension class, because the object should exist for the entire
+    instance of this Extension class, because the object must exist for the entire
     lifetime of the PHP process, and not only for the duration of the get_module()
     call. The constructor takes two arguments: the name of your extension and 
     its version number. The Extension::module() method returns the memory address
     that PHP needs to initialize the library.
 </p>
 <p>
-    Note that the example above does not yet make any native functions or 
-    native classes available in PHP - it only creates the extension.
+    Note that the example above does not yet export any native functions or 
+    native classes to PHP - it only creates the extension. 
 </p>
-<h1>Exporting native functions</h1>
+<h2>Exporting native functions</h2>
 <p>
-    An extension is of course only useful if you define functions and/or 
+    An extension can of course only be useful if you define functions and/or 
     classes that can be accessed from PHP scripts. For functions you can do this 
     by adding your native function implementations to the Extension object:
 </p>
@@ -106,9 +131,9 @@
         #include &lt;phpcpp.h&gt;
         
         extern void example1();
-        extern void example2(Php::Parameters &params);
+        extern void example2(Php::Parameters &amp;params);
         extern Php::Value example3();
-        extern Php::Value example4(Php::Parameters &params);
+        extern Php::Value example4(Php::Parameters &amp;params);
         
         extern "C" {
             PHPCPP_EXPORT void *get_module() {
@@ -158,13 +183,57 @@
     </pre></code>
 </p>
 <p>
-    The signature of the four example functions are exactly the signatures that
-    are supported by the PHP-CPP libraries. Every native function that returns
-    void or a Php::Value object, and that either accepts a Php::Parameters object
+    It is not possible to export every thinkable C/C++ function to the 
+    PHP extension. Only functions that have one of the four supported signatures
+    can be exported: functions that return
+    void or a Php::Value object, and that either accept a Php::Parameters object
     or no parameters at all, can be added to the extension object and can thus
     be exported to PHP.
 </p>
-<h1>Working with variables</h1>
+<h2>Parameter types</h2>
+<p>
+    PHP has a mechanism to enforce function parameters types, and to accept
+    parameters either by reference or by value. In the examples above, we have
+    not yet used that mechanism yes: it is up to the function implementations
+    themselves to inspect the 'Parameters' object, and check if the
+    variables are of the right type.
+</p>
+<p>
+    However, the 'Extension::add()' method takes a third optional parameter that
+    you can use to specify the number of parameters that are supported, whether
+    the parameters are passed by reference or by value, and what the type of
+    the parameters is:
+</p>
+<p>
+    <code><pre>
+        #include &lt;phpcpp.h&gt;
+        
+        extern void example(Php::Parameters &amp;params);
+        
+        extern "C" {
+            PHPCPP_EXPORT void *get_module() {
+                static Php::Extension myExtension("my_extension", "1.0");
+                myExtension.add("example", example, {
+                    Php::ByVal("a", Php::numericType),
+                    Php::ByVal("b", "ExampleClass"),
+                    Php::ByRef("c", "OtherClass")
+                });
+                return myExtension.module();
+            }
+        }
+    </pre></code>
+</p>
+<p>
+    Above you see that we pass in additional information when we register the         
+    
+
+
+    The Extension::add() method can be used to register native functions, and
+    make them available in PHP. In the examples above, you've seen that the
+    method takes two parameters: the name the function shou
+
+
+<h2>Working with variables</h2>
 <p>
     Variables in PHP are non-typed. A variable can thus hold any possible type:
     an integer, string, a floating point number, and even an object or an array.
diff --git a/include/array.h b/include/array.h
new file mode 100644
index 0000000..6956fee
--- /dev/null
+++ b/include/array.h
@@ -0,0 +1,83 @@
+/**
+ *  Array.h
+ *
+ *  An array is an extension to the Value class. It extends the Value class
+ *  to initialize the variable as an array, instead of a null pointer
+ *
+ *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
+ *  @copyright 2013 Copernica BV
+ */
+
+/**
+ *  Set up namespace
+ */
+namespace Php {
+    
+/**
+ *  Class definition
+ */
+class Array : public Value
+{
+public:
+    /**
+     *  Constructor
+     */
+    Array() : Value() { setType(arrayType); }
+    
+    /**
+     *  Copy constructor
+     *  @param  array
+     */
+    Array(const Array &array) : Value(array) {}
+    
+    /**
+     *  Move constructor
+     *  @param  array
+     */
+    Array(Array &&that) : Value(std::move(that)) {}
+    
+    /**
+     *  Copy constructor from a value object
+     *  @param  value
+     */
+    Array(const Value &value) : Value(value) { setType(arrayType); }
+    
+    /**
+     *  Destructor
+     */
+    virtual ~Array() {}
+
+    /**
+     *  Change the internal type of the variable
+     *  @param  Type
+     */
+    virtual Value &setType(Type type) override
+    {
+        // only possible for arrays
+        if (type != arrayType) return *this;
+        
+        // call base
+        return Value::setType(type);
+    }
+    
+protected:
+    /**
+     *  Validate the object
+     *  @return Value
+     */
+    virtual Value &validate() override
+    {
+        // make sure the value object is an array
+        setType(arrayType);
+        
+        // call base
+        return Value::validate();
+    }
+    
+};
+    
+/**
+ *  End of namespace
+ */
+}
+
diff --git a/include/exception.h b/include/exception.h
index ccb6b08..061c106 100644
--- a/include/exception.h
+++ b/include/exception.h
@@ -1,9 +1,9 @@
 /**
- * 	Exception.h
- * 	Implementation of Php Exceptions.
+ *  Exception.h
+ *  Implementation of Php Exceptions.
  * 
- * 	@author Jasper van Eck <jasper.vaneck@copernica.com>
- * 	@copyright 2013 Copernica BV
+ *  @author Jasper van Eck <jasper.vaneck@copernica.com>
+ *  @copyright 2013 Copernica BV
  */
 #include <exception>
 
@@ -18,42 +18,42 @@ namespace Php {
 class Exception : public std::exception
 {
 private:
-	/**
-	 * 	The exception message
-	 * 	@var	char*
-	 */
-	std::string _message;
-	
-	/**
-	 * 	The PHP exception code
-	 * 	@var	int
-	 */
-	int _code;
-	
+    /**
+     *  The exception message
+     *  @var    char*
+     */
+    std::string _message;
+    
+    /**
+     *  The PHP exception code
+     *  @var    int
+     */
+    int _code;
+    
 public:
-	/**
-	 * 	Constructor
-	 * 	@param	&string
-	 */
-	Exception(const std::string &message, int code = 0) : std::exception(), _message(message), _code(code)
-	{
-	}
-	
-	/**
-	 *  Destructor
-	 */
-	virtual ~Exception()
-	{
-	}
-	
-	/**
-	 * 	Returns the message of the exception.
-	 * 	@return &string
-	 */
-	std::string &message() throw()
-	{
-		return _message;
-	}
+    /**
+     *  Constructor
+     *  @param  &string
+     */
+    Exception(const std::string &message, int code = 0) : std::exception(), _message(message), _code(code)
+    {
+    }
+    
+    /**
+     *  Destructor
+     */
+    virtual ~Exception()
+    {
+    }
+    
+    /**
+     *  Returns the message of the exception.
+     *  @return &string
+     */
+    std::string &message() throw()
+    {
+        return _message;
+    }
 };
 
 /**
diff --git a/include/extension.h b/include/extension.h
index 3555fb6..862549a 100644
--- a/include/extension.h
+++ b/include/extension.h
@@ -35,7 +35,7 @@ class Extension;
 
 /**
  *  Optional callback types for starting and stopping the request
- * 	@param	extension
+ *  @param  extension
  */
 typedef bool    (*request_callback)(Extension *extension);
 
diff --git a/include/globals.h b/include/globals.h
index b3ee6c3..6faeb8a 100644
--- a/include/globals.h
+++ b/include/globals.h
@@ -1,11 +1,11 @@
 /**
  *  Globals.h
  *
- * 	Wrapper object that gives access to all global variables. You
+ *  Wrapper object that gives access to all global variables. You
  *  can use it more or less the same as the $_GLOBALS object in
- * 	PHP.
+ *  PHP.
  * 
- * 	The global PHP variables are acessible via the Php::globals["varname"]
+ *  The global PHP variables are acessible via the Php::globals["varname"]
  *  variables.
  *
  *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
@@ -87,16 +87,16 @@ private:
     Globals() {}
     
 public:
-	/**
-	 *  Get the one and only instance
-	 *  @return	Globals
-	 */
-	static Globals &instance();
+    /**
+     *  Get the one and only instance
+     *  @return Globals
+     */
+    static Globals &instance();
 };
 
 /**
  *  We always have one instance
- *	@var	Globals
+ *  @var    Globals
  */
 extern Globals &globals;
 
diff --git a/include/value.h b/include/value.h
index b2ce89b..09392ad 100644
--- a/include/value.h
+++ b/include/value.h
@@ -264,7 +264,7 @@ public:
      *  Change the internal type of the variable
      *  @param  Type
      */
-    Value &setType(Type type);
+    virtual Value &setType(Type type);
 
     /**
      *  Make a clone of the value with the same type
@@ -290,7 +290,7 @@ public:
     bool isFloat()      const { return type() == floatType; }
     bool isObject()     const { return type() == objectType; }
     bool isArray()      const { return type() == arrayType; }
-    bool isCallable() 	const;
+    bool isCallable()   const;
     
     /**
      *  Retrieve the value as number
@@ -531,7 +531,7 @@ public:
     /**
      *  Call the function in PHP
      *  We have ten variants of this function, depending on the number of parameters
-     * 	This call operator is only useful when the variable represents a callable
+     *  This call operator is only useful when the variable represents a callable
      *  @param  name        Name of the function
      *  @return Value
      */
@@ -548,13 +548,13 @@ public:
     Value operator()(Value p0, Value p1, Value p2, Value p3, Value p4, Value p5, Value p6, Value p7, Value p8, Value p9);
 
 private:
-	/**
-	 *  Call function with a number of parameters
-	 *  @param  argc        Number of parameters
-	 *  @param  argv        The parameters
-	 *  @return Value
-	 */
-	Value exec(int argc, struct _zval_struct ***params);
+    /**
+     *  Call function with a number of parameters
+     *  @param  argc        Number of parameters
+     *  @param  argv        The parameters
+     *  @return Value
+     */
+    Value exec(int argc, struct _zval_struct ***params);
 
 protected:
     /**
@@ -564,6 +564,14 @@ protected:
     struct _zval_struct *_val;
     
     /**
+     *  Validate the value
+     *  This is a overridable function that is implemented in base classes to
+     *  ensure that a value of certain type stays valid
+     *  @return Value
+     */
+    virtual Value &validate() { return *this; }
+    
+    /**
      *  The Globals and Member classes can access the zval directly
      */
     friend class Globals;
diff --git a/phpcpp.h b/phpcpp.h
index 0f99a5e..236a93a 100644
--- a/phpcpp.h
+++ b/phpcpp.h
@@ -24,6 +24,7 @@
  */
 #include <phpcpp/type.h>
 #include <phpcpp/value.h>
+#include <phpcpp/array.h>
 #include <phpcpp/hiddenpointer.h>
 #include <phpcpp/globals.h>
 #include <phpcpp/argument.h>
diff --git a/src/includes.h b/src/includes.h
index ae8956f..18e9951 100644
--- a/src/includes.h
+++ b/src/includes.h
@@ -37,6 +37,7 @@
  */
 #include "../include/type.h"
 #include "../include/value.h"
+#include "../include/array.h"
 #include "../include/hiddenpointer.h"
 #include "../include/globals.h"
 #include "../include/argument.h"
diff --git a/src/value.cpp b/src/value.cpp
index b0c3350..194934d 100644
--- a/src/value.cpp
+++ b/src/value.cpp
@@ -299,7 +299,7 @@ Value &Value::operator=(Value &&value)
     }
 
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -345,7 +345,7 @@ Value &Value::operator=(const Value &value)
     }
     
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -365,7 +365,7 @@ Value &Value::operator=(int16_t value)
     ZVAL_LONG(_val, value);
 
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -385,7 +385,7 @@ Value &Value::operator=(int32_t value)
     ZVAL_LONG(_val, value);
 
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -405,7 +405,7 @@ Value &Value::operator=(int64_t value)
     ZVAL_LONG(_val, value);
 
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -425,7 +425,7 @@ Value &Value::operator=(bool value)
     ZVAL_BOOL(_val, value);
 
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -445,7 +445,7 @@ Value &Value::operator=(char value)
     ZVAL_STRINGL(_val, &value, 1, 1);
     
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -465,7 +465,7 @@ Value &Value::operator=(const std::string &value)
     ZVAL_STRINGL(_val, value.c_str(), value.size(), 1);
     
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -485,7 +485,7 @@ Value &Value::operator=(const char *value)
     ZVAL_STRING(_val, value, 1);
     
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -505,7 +505,7 @@ Value &Value::operator=(double value)
     ZVAL_DOUBLE(_val, value);
     
     // update the object
-    return *this;
+    return validate();
 }
 
 /**
@@ -971,8 +971,6 @@ long Value::numericValue() const
     // already a long?
     if (isNumeric()) return Z_LVAL_P(_val);
     
-    std::cout << "clone to numeric" << std::endl;
-    
     // make a clone
     return clone(numericType).numericValue();
 }
@@ -1208,6 +1206,9 @@ const Value &Value::set(int index, const Value &value)
     // the variable has one more reference (the array entry)
     Z_ADDREF_P(value._val);
     
+    // object should stay valid
+    validate();
+    
     // done
     return value;
 }
@@ -1243,6 +1244,9 @@ const Value &Value::set(const char *key, int size, const Value &value)
     // the variable has one more reference (the array entry)
     Z_ADDREF_P(value._val);
     
+    // object should stay valid
+    validate();
+    
     // done
     return value;
 }