regression/fail/equality-types.sml

   1 val _ = 1 = 2
   2
   3 val _ = 1.0 = 2.0 (* error *)
   4
   5 val f: ''a -> unit = fn _ => raise Fail "f"
   6
   7 val _ = f 1
   8
   9 val _ = f 1.0 (* error *)
  10
  11 datatype 'a t = T of 'a
  12
  13 val _ = T 1 = T 2
  14
  15 val _ = T 1.0 = T 2.0 (* 15 error *)
  16
  17 datatype 'a t = T
  18
  19 val _ = (T: int t) = T
  20
  21 val _ = (T: real t) = T (* 21 error *)
  22
  23 datatype t = T of u
  24 withtype u = real
  25
  26 val _ = T 13.0 = T 14.0 (* 26 error *)
  27
  28 datatype t = T of u
  29 and u = U of t
  30
  31 fun f (x: t) = x = x
  32
  33 datatype 'a t = T of 'a u
  34 and 'a u = U of 'a
  35
  36 fun f (x: int t) = x = x
  37
  38 fun f (x: real t) = x = x (* 38 error *)
  39
  40 val f: 'a -> unit = fn x => (x = x; ()) (* 40 error *)