(module example mzscheme
  (require (planet "test.ss" ("schematics" "schemeunit.plt" 2 8))
           (planet "text-ui.ss" ("schematics" "schemeunit.plt" 2 8))
           (lib "list.ss")
           "join-forest.ss")
  
  (define (node-join node-1 node-2)
    (list node-1 node-2))
  
  (define (node-left a-node)
    (first a-node))
  
  (define (node-right a-node)
    (second a-node))
  
  (define (node-depth a-node)
    (cond
      [(pair? a-node)
       (add1 (max (node-depth (node-left a-node))
                  (node-depth (node-right a-node))))]
      [else 0]))
  
  (define tree1 '(1 (2 3)))
  (define tree2 '((4 5) 6))
  (define tree3 '((7 8) 9))
  (define tree4 '10)
  (define tree5 '11)
  (define a-forest (list tree1 tree2 tree3 tree4 tree5))
  
  (define example-tests
    (test-suite
     "example.ss"
     (test-case
      "comparison"
      (check-equal? (node-depth (naive-join-forest a-forest node-join))
                    6)
      (check-equal? (node-depth (simple-join-forest a-forest node-join))
                    5)
      (check-equal? (node-depth
                     (optimal-join-forest a-forest node-join node-depth))
                    4))))
  
  (test/text-ui example-tests))