for %hash.kv -> my $key, $val {
    say "$key corresponds to $val";
}

##</code><code>##

 use strict;
use warnings;
 
{ my %lists;
 
  sub deal {
    my $aref=shift;
    my $id= \$_[0];
    #print $aref,$id;
    $lists{$id}=$aref if (! exists $lists{$id} );
    if (@{$lists{$id}}){
      for(@_) {
	$_=shift @{$lists{$id}};
      }
      return 1; 
      # could be extended to
      #  * iteration counter
      #  * remaining list-elements
      #  * a list of all of these
    } else {
      delete $lists{$id};
      return 0;
    }
  }
}
 
$\="\n";
 
#--------- here we go 
while (deal [1..9] => my ($a,$b,$c) ){
  print $a,$b,$c;
  while (deal [a=>1,b=>2] => my ($a,$b) ){
    print $a,$b;
  }
}
#--------- 
print "EXIT";
 
__DATA__ 
123
a1
b2
456
a1
b2
789
a1
b2
EXIT

##</code><code>##

while( deal {a=>1,b=>2} my($k,$v) ) {..}