Introducing the new param() function as early as possible

Author: ThomasLandauer

configuration.rst

@@ -298,7 +298,7 @@ reusable configuration value. By convention, parameters are defined under the
 
 Once defined, you can reference this parameter value from any other
 configuration file using a special syntax: wrap the parameter name in two ``%``
-(e.g. ``%app.admin_email%``):
+(e.g. ``%app.admin_email%``). In PHP you can also use the ``param()`` function:
 
 .. configuration-block::
 
@@ -309,8 +309,6 @@ configuration file using a special syntax: wrap the parameter name in two ``%``
             # any string surrounded by two % is replaced by that parameter value
             email_address: '%app.admin_email%'
 
-            # ...
-
     .. code-block:: xml
 
         <!-- config/packages/some_package.xml -->
@@ -333,13 +331,13 @@ configuration file using a special syntax: wrap the parameter name in two ``%``
 
         // config/packages/some_package.php
         namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+        use function Symfony\Component\DependencyInjection\Loader\Configurator\param;
 
         return static function (ContainerConfigurator $containerConfigurator) {
             $containerConfigurator->extension('some_package', [
-                // any string surrounded by two % is replaced by that parameter value
+                'email_address' => param('app.admin_email'),
+                // or:
                 'email_address' => '%app.admin_email%',
-
-                // ...
             ]);
         };