You build arrays of zeros and ones here, but usually I prefer strings. Here's an interesting way to build an iterator for all strings of length n, base b, given an appropriate b:

sub iterator {
  my($n, $b) = @_;
  my $limit = $b - 1;
  die "base out of range" unless $limit =~ /^\d$/;
  my $str;
  sub {
    return $str = "0" x $n unless defined $str;
    return $str =~ s/([^$limit])($limit*)$/($1+1)."0" x length($2)/e
      ? $str : undef;
  }
}

# Usage:
my $iterator = iterator(5, 2);
while (defined($next = $iterator->())) {
  print "next: $next\n";
}

[download]

Hugo

In reply to Re: Generate all (0,1)-sequences in lexicographic order by hv
in thread Generate all (0,1)-sequences in lexicographic order by FoxtrotUniform

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