Sequential Access

• ->seq provides generic sequential access to the keys

  • In the user-defined order

• Note: C-style for loops coming up

• To scan the keys forwards:

 my $db = tied %hash;
 my ($k, $v, $fail);
 for ($fail = $db->seq($k, $v, R_FIRST) ;
 ! $fail ;
 $fail = $db->seq($k, $v, R_NEXT)
 ) {
 print "$k => $v\n";
 }

• Or backwards:

 for ($fail = $db->seq($k, $v, R_LAST);
 ! $fail;
 $fail = $db->seq($k, $v, R_PREV)
 ) {
 print "$k => $v\n";
 }

• Or just the keys between $a and $b:

 $k = $a;
 for ($fail = $db->seq($k, $v, R_CURSOR);
 ! $fail && $k le $b;
 $fail = $db->seq($k, $v, R_NEXT)
 ) {
 print "$k => $v\n";
 }