sub scanl(&@) {
    my ($f, @rv) = @_;
    $rv[$_] = $f->($rv[$_-1], $rv[$_])
       for 1..$#rv;
    return @rv;
}

my @rv = scanl \&divide, 64, 4,2,4;
   -or-
my @rv = scanl { $_[0] / $_[1] } 64, 4,2,4;