2.4 Composite

  • Composite
  • When you have objects arranged in a tree structure, this pattern will help you make clients simple. Clients do not need to worry whether they are speaking to a single object or a large group of objects. We explain why the interface at the top of the hierarchy seems too general, but is in fact exactly the way that it should be.

    • Recursively visiting
    • One of the posers of this pattern is how to find all leaves of the tree without building up a temporary list. In our exercise we discover how to do this in code.