You could use a temporary: 
my @order;
for my $key (keys %HoA) {
  if ($key eq 'Foo') {
    unshift @order, $key;
  } else {
    push @order, $key;
  }
}
for my $key (@order) { ... }

[download]
and, of course, there are many ways to pronounce that: 
my @order;
for my $key (keys %HoA) {
  ($key eq 'Foo') ? unshift(@order, $key) : push(@order, $key);
}

[download]
or 
my @order;
for my $key (keys %HoA) {
  splice(@order, ($key eq 'Foo') ? 0 : @order, (), $key);
}

[download]

Or you could take a totally different approach: 

my %early = my %late = %HoA; # or map { $_ => 1 } keys %HoA
delete $late{Foo};
delete @early{keys %late};
for my $key (keys %early, keys %late) { ... }

[download]

In reply to Re: Pulling an item to the front of the list by sfink
in thread Pulling an item to the front of the list by Tanktalus

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