title: TCL/ITCL - implementing unique data structure using existing data structure
body: <p>I am new to tcl/Itcl programming.<br>
  Is there any data structure in tcl or Itcl or any packages provided for those two that can help me implement the next structure (see the picture below).</p>
  
  <p><strong>Explanation of the data structure:</strong><br>
  This data structure is very similar to B-Tree data structure.<br>
  But , Every level of the data structure is different class meaning class A can have <strong>only</strong> child of type class B.<br>
  Every "class type" in any level (Node) has another data that is unique to this class in addition to the "pointers" to parent and children of this "Node".</p>
  
  <p>I saw there is the struct::tree data structure but I don't really know if I can use this data structure to implement my data structure with those exceptions.<br>
  Is there any way to implement it except creating a "node base class" and 3 more class that inherits from this "node base class" with unique list in each one?</p>
  
  <p><a href="https://i.stack.imgur.com/nKrHM.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/nKrHM.jpg" alt="enter image description here"></a></p>