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Re^2: Hash order randomization is coming, are you ready?

by demerphq (Chancellor)
on Dec 02, 2012 at 11:17 UTC ( #1006702=note: print w/ replies, xml ) Need Help??


in reply to Re: Hash order randomization is coming, are you ready?
in thread Hash order randomization is coming, are you ready?

Since we have to maintain the same order between values() and keys() I do not think that we can change this. However IMO you should not depend on it.

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$world=~s/war/peace/g


Comment on Re^2: Hash order randomization is coming, are you ready?
Re^3: Hash order randomization is coming, are you ready?
by Tanktalus (Canon) on Dec 02, 2012 at 14:49 UTC

    Maintaining the same order between values and keys should mean you can depend on keys returning the same order each time, otherwise how is values supposed to know which order to present its order?

    my @keys1 = keys %some_hash; my @keys2 = keys %some_hash; #different from @keys1? my @values = values %some_hash; # same order as @keys1 or same as @key +s2?
    That makes it look pretty dependable to me, assuming: a) same process (or a fork of it), and b) hash otherwise unchanged between the two calls to keys.

    Personally, I only rely on the order when I'm doing something like @hash2{keys %hash1} = values %hash1;, otherwise I don't think I ever rely on the order from keys (if I care, I sort them) or values (there's no real way to sort values the same as sorting keys anyway), so I doubt I'm affected, but only one way to find out. :-)

      otherwise how is values supposed to know which order to present its order?

      That is the question really. :-) If it is possible then it might be done. I wouldn't assume its impossible, even though I think it is likely to be impossible.

      ---
      $world=~s/war/peace/g

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