I can't believe no one has mentioned this (admittedly it isn't directly related to the Anonymous Monk's question): it will be possible to manipulate Perl 6 arrays with set theory-style operators. There was a Perl 6 RFC proposed, and Damian Conway's talk at YAPC::Europe this year seemed to confirm that. About one half of the audience loved it, the rest seemed to be a bit concerned at some of the incredibly cool Perl 6 features that were presented.

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Now once "they" (Larry et al.) decide to forget the silly idea of removing foreach and having only for, I'll be completely happy with Perl 6. Apparently code like:
foreach my $person (@addressbook) {

doesn't make sense or looks ugly. Well, I read that as "for each of my people in the address book, do something". It makes sense to me!
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