in reply to re-key a hash

A hash is great if the data is sparsely populated, but if you make the keys sequential integers, why not go with an array?

my @array = @hash{ sort {$a <=> $b} keys %hash};

Incidentally, note that you're deleting hash elements while iterating over it. You're not supposed to do that.

Update: To keep a hash, try something like this:

my %hash2;
@hash2{ 0 .. (keys %hash)-1 } = map { $hash{$_} } sort {$a <=> $b} key
+s %hash;

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It's really ugly, though :)

Update 2 ysth and Aristotle both caught me sleeping. Pay no attention to the man in the classical poet outfit.

Cheers,
Ovid

New address of my CGI Course.

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Re^2: re-key a hash
by Aristotle (Chancellor) on Aug 02, 2004 at 21:46 UTC 
    @hash2{ 0 .. (keys %hash)-1 } = map { $hash{$_} } sort {$a <=> $b} key
+s %hash;

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    You had it right before; why did you think you need the map there?

    @hash2{ 0 .. (keys %hash)-1 } = @hash{ sort { $a <=> $b } keys %hash }
+;

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    I'm too lazy to verify, but I think you don't need to assign to a separate hash if you do it this way, either. The list should be assigned atomically once it is built completely.

    Makeshifts last the longest.

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Re^2: re-key a hash
by ysth (Canon) on Aug 02, 2004 at 21:41 UTC
    You are explicitly allowed to delete each element as you iterate; you ought not to make other changes (as this code does).
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      I can understand the caveat if you're iterating over values or with each, but sort keys is not a hash iterator.
      We're not really tightening our belts, it just feels that way because we're getting fatter.
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        You're right; I misread the loop. There's no problem at all, then, except that the code doesn't do what he wants.
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