regression/poly-equal.2.sml

   1 fun assert (msg,b) =
   2    if b then ()
   3    else print ("assertion failed: " ^ msg ^ "\n")
   4
   5 datatype 'a tree =
   6    Leaf of 'a
   7   | Node of 'a * 'a tree * 'a tree
   8
   9 val _ =
  10    (assert ("string equal", "foobar" = "foobar") ;
  11     assert ("string not equal", "foobar" <> "foobaz") ;
  12     assert ("tuple equal", (1,2,3) = (1,2,3)) ;
  13     assert ("tuple not equal", (1,2,3) <> (1,2,4)) ;
  14     assert ("list equal", [1,2,3] = [1,2,3]) ;
  15     assert ("list not equal", [1,2,3] <> [1,2,3,4]) ;
  16     assert ("pair list equal", [(1,2), (3,4)] = [(1,2), (3,4)]) ;
  17     assert ("pair list not equal", [(1,2), (3,4)] <> [(1,2), (3,5)]) ;
  18     assert ("tree equal",
  19            let val t = Node (1, Leaf 2, Node (3, Leaf 4, Leaf 5))
  20            in t = t
  21            end))
  22
  23
  24