gistfile1.raku

sub trait_mod:<is> (Sub:D $s, :$partial) {
  $s.wrap(sub (*%_) {
    if %_.elems == $s.signature.params.elems {
      callwith |%_;
    } else {
      my %cache = %_;
      return sub (*%_) {
        $s.(|%_, |%cache);
      };
    };
  });
};

sub x (:$name, :$title) is partial {
  "{$title}. {$name}".say;
};

x(:name<tony>, :title<m>);

my $partial = x(:name<tony>);
$partial.(:title<m2>)