see mugwumpjism's prior art in his response to the mapcar -- map for more than one list node.

code here for those too lazy to click above...

sub mapeach (&\%)
{
    my $sub = shift;
    my $hash = shift or do {
        require Carp;
        Carp::croak( "mapeach: Nothing to map" );
    };

    my @ret;
    while ( my ($k, $v) = each %{$hash}) {
    local ($_) = $k;
    push @ret, $sub->($k, $v);
    }

    return wantarray ? @ret : { @ret };
}
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~Particle *accelerates*