sub caller {
        [yadda yadda]
        
        my $args = [];
        
        do {
            $result = $f->($args);
            [yadda yadda]
        } while ($f);
        
        return ($result);
    }
    
    sub as_list {
        my $args = shift;
        
        my ($arg1, $arg2, $arg3) = @$args;
        @$args = ();
        
        [...]
    }
    
    sub as_stack {
        my $args = shift;
        my $item = pop @$args;
        
        [...]
        
        push @args, $result;
        
        return ([true|false]);
    }
    
    sub as_queue {
        my $args = shift;
        my $item = shift @$args;
        
        [...]
        
        push @args, $result;
        
        return ([true|false]);
    }