use types to disambiguate record access

git-svn-id: http://caml.inria.fr/svn/ocaml/branches/record-disambiguation@12934 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

testsuite/tests/typing-misc/records.ml

@@ -27,3 +27,17 @@ end;;
 (* path abbreviation is syntactic *)
 let f {M.x; y} = x+y;; (* fails *)
 let r = {M.x=1; y=2};; (* fails *)
+
+(* Use type information *)
+let f (x:Complex.t) = x.re;;
+let f x = ignore (x:Complex.t); x.re;; (* non principal *)
+module M = struct
+  type t = {x:int}
+  module N = struct type s = t = {x:int} end
+  type u = { x:bool}
+end;;
+let f (r:M.u) = r.x;;
+let f (r:M.t) = r.x;; (* fails *)
+open M.N;;
+let f r = r.x;;
+let f (r:M.t) = r.x;; (* ok *)

testsuite/tests/typing-misc/records.ml.principal.reference

@@ -0,0 +1,60 @@
+
+#   type t = { x : int; y : int; }
+# Characters 5-6:
+  {x=3;z=2};;
+       ^
+Error: Unbound record field label z
+# Characters 9-10:
+  fun {x=3;z=2} -> ();;
+           ^
+Error: Unbound record field label z
+#     Characters 26-34:
+  {x=3; contents=2};;
+        ^^^^^^^^
+Error: The record field label Pervasives.contents belongs to the type 
+       'a ref but is mixed here with labels of type t
+#     type u = private { mutable u : int; }
+# Characters 0-5:
+  {u=3};;
+  ^^^^^
+Error: Cannot create values of the private type u
+# Characters 11-12:
+  fun x -> x.u <- 3;;
+             ^
+Error: Cannot assign field u of the private type u
+#         module M : sig type t = { x : int; y : int; } end
+#   val f : M.t -> int = <fun>
+# val r : M.t = {M.x = 1; y = 2}
+# val z : int = 3
+#         module M : sig type t = { x : int; y : int; } type u = { y : bool; } end
+#   Characters 43-51:
+  let f {M.x; y} = x+y;; (* fails *)
+        ^^^^^^^^
+Error: This pattern matches values of type M.u
+       but a pattern was expected which matches values of type M.t
+# Characters 16-17:
+  let r = {M.x=1; y=2};; (* fails *)
+                  ^
+Error: The record field label M.y belongs to the type M.u
+       but is mixed here with labels of type M.t
+#     val f : Complex.t -> float = <fun>
+# Characters 32-36:
+  let f x = ignore (x:Complex.t); x.re;; (* non principal *)
+                                  ^^^^
+Warning 18: this type-based field selection is not principal.
+val f : Complex.t -> float = <fun>
+#         module M :
+  sig
+    type t = { x : int; }
+    module N : sig type s = t = { x : int; } end
+    type u = { x : bool; }
+  end
+# val f : M.u -> bool = <fun>
+# Characters 16-17:
+  let f (r:M.t) = r.x;; (* fails *)
+                  ^
+Error: This expression has type M.t but an expression was expected of type
+         M.u
+# # val f : M.N.s -> int = <fun>
+# val f : M.t -> int = <fun>
+# 

testsuite/tests/typing-misc/records.ml.reference

@@ -37,4 +37,20 @@ Error: This pattern matches values of type M.u
                   ^
 Error: The record field label M.y belongs to the type M.u
        but is mixed here with labels of type M.t
+#     val f : Complex.t -> float = <fun>
+# val f : Complex.t -> float = <fun>
+#         module M :
+  sig
+    type t = { x : int; }
+    module N : sig type s = t = { x : int; } end
+    type u = { x : bool; }
+  end
+# val f : M.u -> bool = <fun>
+# Characters 16-17:
+  let f (r:M.t) = r.x;; (* fails *)
+                  ^
+Error: This expression has type M.t but an expression was expected of type
+         M.u
+# # val f : M.N.s -> int = <fun>
+# val f : M.t -> int = <fun>
 #