in reply to Re^2: Opinions on adding functionality to Tie::Hash::Sorted
in thread Opinions on adding functionality to Tie::Hash::Sorted

Hmmm, I just thought of another method that might be useful: rewind, to reset the iterator. But that's probably low priority, seeing as there's no natural way to express that for unordered hashes in Perl.
  • Comment on Re^3: Opinions on adding functionality to Tie::Hash::Sorted

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Re^4: Opinions on adding functionality to Tie::Hash::Sorted
by Limbic~Region (Chancellor) on Jul 18, 2004 at 15:24 UTC
    gaal,
    seeing as there's no natural way to express that for unordered hashes in Perl.

    The iterator is reset anytime there is a new call to keys, or values. each will only do this once it reaches the end of the hash. This can cause very unexpected behavior if you mix and match - see the following: 

    #!/usr/bin/perl
use strict;
use warnings;

my %hash = (one=>1, two=>2, three=>3, four=>4, five=>5);
my $flag; # prevent infinite loop
while ( my ($key, $val) = each %hash ) {
    if ( $val == 4 && ! $flag ) {
        my @keys = keys %hash;
        print "\t$_\n" for @keys;
        $flag = 1;
    }
    print "$key : $val\n";
}

    [download]
    There very well may be some good in saving off the iterator, resetting it, and restoring it so this doesn't go bonkers as it does with real hashes. I will have to give some thought to this though.

    Cheers - L~R

    Modified wording with regards to resetting iterator as pointed out by davido.
[reply]
[d/l]
      Yikes! I wasn't aware of that; for some reason I'd been assuming each each keeps its own state, somewhat like ..s do.

      Thanks for the heads up!
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