regression/functor.sml

   1 signature A = sig type t val a : t end
   2
   3 functor F(A : sig type t val pr : t -> string end) =
   4   struct datatype k = A of A.t
   5          fun pr (A t) = "A(" ^ A.pr t ^ ")"
   6   end
   7
   8 functor G(A : A) =
   9   struct type t = A.t val b = A.a end
  10
  11 functor H(A : sig type t type s val a : s
  12                   sharing type t = s
  13                   val pr : t -> string
  14               end) =
  15   struct
  16     structure A1 : sig type t val pr : t -> string end = A
  17     structure A2 = F(A1)
  18     structure A3 = G(A)
  19     val a = A2.A A.a
  20     val _ = print ("value is " ^ A2.pr a ^ "\n")
  21   end
  22
  23 structure B1 =
  24   struct
  25     datatype t = J | K
  26     type s = t
  27     val a = K
  28     fun pr K = "K"
  29       | pr J = "J"
  30   end
  31
  32 structure B2 =
  33   struct open B1
  34     val a = J
  35   end
  36
  37 structure H1 = H(B1)
  38 structure H2 = H(B2)
  39
  40 signature S = sig end
  41
  42 functor F (): S = struct end
  43
  44 signature S = sig val y: int end
  45
  46 structure C = F ()