# The for loop

    my @foo = <clojure scala rust>;  # auto-quote, qw//

    for @foo        { .say }  # $_ is implicit as read-write variable
    for @foo <-> $_ { .say }  # explicit form of default $_

    for @foo -> $item { say "$item," }  # $item is read-only by default

    for @foo ->  $item is rw { $item = "perl6" if $item ~~ m/rust/ }
    for @foo <-> $item       { $item = "rust" if $item ~~ m/perl6/ }

See: http://perlcabal.org/syn/S04.html