First off you cant "predefine" your data structure in Perl. There is no means by which you can explicitly specify your data structure. Instead Perl provides for easy ways to implicitly define your data structure. As well as interact with it and redefine it on the fly.

So how to do some of the things you want to do...

my %struct;
foreach my $elem (@elements) { # loop over all the elements

  # check to make sure our hash key has an array we can push onto.
  $struct{$elem->name}=[] unless $struct{$elem->name};

  # now create a new sub hash to push onto the array later
  my %hash=(text=>$elem->text, attributes=>[]); #initialize it 

  # loop over each attribute in the element
  foreach my $attrib ($elem->attribs) {

    # push the elements onto the attributes array
    push @{$hash{attributes}},$attrib->name,$attrib->value;

  }

  # push a reference to the newly created hash on the array stored for
+ this element type.
  push @{$struct{$elem->name}},\%hash;
}
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Now of course you will have to figure out how to convert the pseudo methods ive used here into the real thing. Also, iirc XML does not allow for two attributes of the same name in one tag, so instead of using an array to store them just use a hash (unless of order is important).

HTH

UPDATE The line where I put an array in explicitly is not needed in this scenario, but if we code like

push @{$hash{$key}},'var' unless @{$hash{$key}}>5;
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we would, because autovivification doesnt happen in that context. Sorry. And just now in the CB chip pointed out that changing the condition to

push @{$hash{$key}},'var' unless @{$hash{$key}||[]}>5;
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would also do the trick, and is probably more elegant, if a touch obfu'd. Thanks chip.

Yves / DeMerphq
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Writing a good benchmark isnt as easy as it might look.