I'm trying to make it easier to follow some [Perl Best Practices](http://oreilly.com/catalog/9780596001735/) by creating a `Constants` module that exports several of the scalars used throughout the book. One in particular, `$EMPTY_STRING`, I can use in just about every Perl script I write. What I'd like is to automatically export these scalars so I can use them without defining them explicitly in each script.

```
#!perl
package Example::Constants;

use Exporter qw( import );
use Readonly;

Readonly my $EMPTY_STRING => q{};
our @EXPORT = qw( $EMPTY_STRING );

```

An example usage:

```
#!perl
use Example::Constants;
print $EMPTY_STRING . 'foo' . $EMPTY_STRING;

```

Using the above code produces an error:

```
Global symbol "$EMPTY_STRING" requires explicit package name

```

If I change the `Readonly` declaration to:

```
Readonly our $EMPTY_STRING => q{}; # 'our' instead of 'my'

```

The error becomes:

```
Attempt to reassign a readonly scalar

```

Is this just not possible with mod\_perl?