Perl,XML :: Twig,如何使用相同的标记读取字段

<?xml version="1.0" encoding="UTF-8"?>
<objects>
  <object>
    <id>VW-XJC9</id>
    <name>Name</name>
    <type>House</type>
    <description>
    <![CDATA[<p>some descrioption of the house</p>]]> </description>
    <localcosts>
      <localcost>
        <type>mandatory</type>
        <name>What kind of cost</name>
        <description>
          <![CDATA[Some text again,different than the first tag]]>
        </description>
      </localcost>
    </localcosts>
  </object>
</objects>

我使用Twig的原因是这个XML大约11GB,大约有100000个不同的对象).问题是当我到达localcosts部分时,会跳过3个字段(类型,名称和描述),可能是因为之前已经使用过这些名称.

我用来浏览xml文件的代码如下：

my $twig= new XML::Twig( twig_handlers => { 
                 id                            => &;get_ID,name                          => &;get_Name,type                          => &;get_Type,description                   => &;get_Description,localcosts                    => &;get_Localcosts
});

$lokaal="c:tempdata3.xml";
getstore($xml,$lokaal);
$twig->parsefile("$lokaal");

sub get_ID          { my( $twig,$data)= @_;  $field[0]=$data->text; $twig->purge; } 
sub get_Name        { my( $twig,$data)= @_;  $field[1]=$data->text; $twig->purge; }
sub get_Type        { my( $twig,$data)= @_;  $field[3]=$data->text; $twig->purge; }
sub get_Description { my( $twig,$data)= @_;  $field[8]=$data->text; $twig->purge; }
sub get_Localcosts{

  my ($t,$item) = @_;

  my @localcosts = $item->children;
  for my $localcost ( @localcosts ) {
    print "$field[0]: $localcost->textn";
    my @costs = $localcost->children;
    for my $cost (@costs) {
      $Type       =$cost->text if $cost->name eq q{type};
      $Name       =$cost->text if $cost->name eq q{name};
      $Description=$cost->text if $cost->name eq q{description};
      print "Fields: $Type,$Name,$Descriptionn";
    }
  }
  $t->purge;    
}

当我运行这段代码时,主要字段被读取没有问题,但是当代码到达’localcosts’部分时,第二个for-next循环不会被执行.当我将xml中的字段名称更改为唯一的名称时,此代码可以正常工作.

有人可以帮我吗？

谢谢