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    <p>Depending on what you need a tree structure for, you might not need any pre-built implementation. Perl already supports them using arrays of arrayrefs.</p> <p>For example, a simple representation of this tree</p> <pre><code> t / \ a d / \ / \ b c e f </code></pre> <p>could be represented by the following Perl code:</p> <pre><code>$tree = [ t =&gt; [ a =&gt; [ b =&gt; [], c =&gt; [] ] d =&gt; [ e =&gt; [], f =&gt; [] ] ] ]; </code></pre> <p>Here, the tree's representation is as nested pairs: first the element (in this case, the letter), then an anonymous array reference representing the children of that element. Note that <code>=&gt;</code> is just a fancy comma in Perl that exempts you having to put quotes around the the token to the left of the comma, provided it is a single word. The above code could also have been written thus:</p> <pre><code>$tree = [ 't', [ 'a' , [ 'b' , [], 'c' , [] ] 'd' , [ 'e' , [], 'f' , [] ] ] ]; </code></pre> <p>Here's a simple depth-first accumulator of all the elements in the tree:</p> <pre><code>sub elements { my $tree = shift; my @elements; my @queue = @$tree; while (@queue) { my $element = shift @queue; my $children = shift @queue; push @elements, $element; unshift @queue, @$children; } return @elements; } @elements = elements($tree) # qw(t a b c d e f) </code></pre> <p>(For breadth first, change the line <code>unshift @queue, @$children</code> to <code>push @queue, @$children</code>)</p> <p>So, depending on what operations you want to perform on your tree, the simplest thing might be just to use Perl's built-in support for arrays and array references.</p>
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Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

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