Update page 'P# 1.0 Draft Specification'

P%23-1.0-Draft-Specification.md

@@ -138,9 +138,11 @@ Callbacks can be denoted in P# language by callback type hint. This pseudo-type
         callback $callme = int() {
             return 7;
         }
-        int $var = $callme();
+        int $var = $callme(); // value is 7
     %>
 
+What is more, P# allows a language constructs in the context of a function call:
+
     <%
         callback $echo = 'print';
         $echo('Hello world'); // Calls the print function on the fly
@@ -251,6 +253,15 @@ TODO
 TODO
 
 ## 8. Object-Oriented Programming
-TODO
+### 8.X. Anonymous Functions
+Anonymous functions, also known as closures, allow the creation of functions which have no specified name. In P#, anonymous function arguments can take a default value exactly like standard function arguments. The default value associated with the function argument can be any complex expression including function calls.
+
+    <%
+        callback $anon = void(string $msg = 'Hello' + ' ' + 'World!' /* Complex expression */){
+            print($msg + PS_EOL);
+        }; // semicolon is required here
+        $anon(); // You should see 'Hello World!'
+        $anon('Welcome guest!'); //You should see 'Welcome guest!'
+    %>