If you reverse their order, it's simply a closure:

$dereferencer = { $^moose.<foo>[1]<bar><baz>[3] };
$dereferencer($datastructure);
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Yep this is very akin to what Joost suggested for Perl 5 (and was also mentioned in the original thread), except that it's more 6ish. I was thinking... is in general the semantics of $datastructure.$dereferencer definite? Is it valid syntax anyway? If not, could a C<.> infix multi, or even a macro, be specified to "amount to" the function call specified above?