the foreach loop is not so convoluted. i spell if f-o-r here.

my @foo = qw(1 4 g 7 h rf s 4 6 7 9);
my %foo = ();

$foo{$_}=$foo[$_] for @foo;
@foo=keys %foo;
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@foo is your original list, and %foo is a temporary hash that you will use to hold the unique values (since every key in a hash is unique).