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=head1 SYNOPSIS

    use Acme::constant ACME => 42;
    print "ACME is now ", ACME, ".\n";
    ACME = 84;
    print "But now, ACME is ", ACME, "\n";

    use Acme::constant LIST => 1, 2, 3;
    print "Second element of list is ", (LIST)[1], ".\n";
    (LIST) = (4, 5, 6);
    print "But now, the second element is ", (LIST)[1], "\n";

=head1 DESCRIPTION

This pragma lets you make inconstant constants, just like the constants
the users of Ruby or Opera (before Opera 14, that is) already enjoyed.

Unlike Perl constants, that are replaced at compile time, Acme
constants, in true dynamic programming language style, can be modified
even after declaration.

Just like constants generated with standard C<use constant> pragma, the
constants declared with C<use Acme::Constant> don't have any sigils.
This makes using constants easier, as you don't have to remember what
sigil do constants use.

=head1 NOTES

As the Perl compiler needs to know about which barewords are keywords,
constants have to defined in C<BEGIN> section. Usually, this is not a
problem, as C<use> statement is automatically put in implicit C<BEGIN>
section, but that also means you cannot dynamically create constants.
For example, in the example below, the C<DEBUG> constant is always
created, with value 1, as C<use> is processed when Perl parser sees
it.

    if ($ENV{DEBUG}) {
        use Acme::constant DEBUG => 1; # WRONG!
    }

It's possible to dynamically use this module using L<if> module,
however, this is likely to cause problems when trying to use constant