recursive type

recursive type

   A data type which contains itself.  The commonest example is
   the list type, in {Haskell}:

   	data List a = Nil | Cons a (List a)

   which says a list of a's is either an empty list or a {cons
   cell} containing an 'a' (the "head" of the list) and another
   list (the "tail").

   Recursion is not allowed in {Miranda} or Haskell {synonym
   types}, so the following {Haskell} types are illegal:

   	type Bad = (Int, Bad)
   	type Evil = Bool -> Evil

   whereas the seeminly equivalent {algebraic data types} are
   acceptable:

   	data Good = Pair Int Good
   	data Fine = Fun (Bool->Fine)