I can't speak to Perl6, but Perl5 provides the tie interface to allow you to put anything you want in place of an array or hash and access it will regular hash or array manipulation. And it provides object construction/method calls for any other kind of access, though in perl5 that means the scalar sigil must be used, unless you do something wacky like:

perl -wle'sub new { bless $_[1] } sub foo { print "foo!" } main->new(\
+my @x); (\@x)->foo()'
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And you can combine the two by saving the tied object or getting it with tied() and calling methods on it to access the tied hash/array in ways not built in to the hash/array interface.

perl -wle'sub foo { print "foo!" } use Tie::Array; @ISA="Tie::StdArray
+"; tie @x, "main"; tied(@x)->foo()'
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(Hey, look, there's no $ sigil there either.)

An example of what you are actually looking to do would have been easier to understand than your description.