signal-trait-golf.p6

gistfile1.txt

use v6;

role Signal {
        has @.slots; # a nice list of callbacks (that are methods)

        multi method connect(Routine $r){
                @.slots.push($r);
        }
}

multi trait_mod:<is>(Routine $r, :$signal!){
        $r does Signal;

# HERE BE DRAGONS
#       say $r.slots.elems; # uncomment this line and it works

        sub handle_call(|$args){
                for $r.slots -> $method {
                        $method(|$args);
                }
        }

        $r.wrap(&handle_call);
}

multi sub connect(Signal $s, Routine $r){
        $s.connect($r);
}

sub bare_slot { say "bare_slot called" }

sub bare_signal_exit is signal {}

connect(&bare_signal_exit, &bare_slot);

bare_signal_exit;