package Parenthise;

sub parenthise {
        my($class, $field_name) = @_;
        my $fullname = join ('::', $class, $field_name);

        my $coderef;
        my $set_coderef = "\$coderef = $fullname;";
        eval $set_coderef;

        my $replace_sub = sub {
            my ($self, $value) = @_;
            if(@_ > 1){
                return $coderef->($self);
            }else{
                return $coderef->($self, "($value)");
            }
        };
       
# here's where the trouble starts
            my $switcheroo = sprintf(<<"HERE" , $class, $field_name, $field_name);
package %s; 
undef &{ *%s{CODE} };
*%s = \$coderef;
HERE                
                    
    eval $switcheroo;
}                       

1;