[Vala] Closure problem in Gtk.AccelGroup

[jezra lickter <jezra jezra net>]

Hello,
basing my work on the documentation found at
http://valadoc.org/gtk+-2.0/Gtk.AccelGroup.connect.html
I am trying to connect an acclegroup to a Closure
code:
AccelGroup accel = new AccelGroup();
accel.connect('q', Gdk.ModifierType.CONTROL_MASK,
        Gtk.AccelFlags.VISIBLE,
        ()=> { 
                stdout.printf("quit"); 
        } );

When I compile my application, I get the following error in regards to
the closure
"error: lambda expression not allowed in this context"

Can someone please tell me what I am doing wrong or point me to a
working example of using AccelGroup.connect()?

jezra