use feature(say);
use Tk;

#create a couple of arbitrary widgets
$main=MainWindow->new;
$can=$main->Canvas(-width => 600, -height => 400)->pack;
$lab=$can->Label(-text => "AAAAAAAA")->place(-x=>100,-y=>100);
$but=$can->Button(-text => "BBBBBBBB")->place(-x=>300,-y=>150);

#use a key binding to invoke an event
$main->bind('<KeyPress-a>',sub{
say $can->find('withtag','current'); #nothing!
});

MainLoop;