Diffing for mismatches in variant and record declarations

.depend

@@ -59,10 +59,23 @@ utils/consistbl.cmx : \
 utils/consistbl.cmi : \
     utils/misc.cmi
 utils/diffing.cmo : \
+    utils/misc.cmi \
     utils/diffing.cmi
 utils/diffing.cmx : \
+    utils/misc.cmx \
+    utils/diffing.cmi
+utils/diffing.cmi : \
+    utils/misc.cmi
+utils/diffing_with_keys.cmo : \
+    utils/misc.cmi \
+    utils/diffing.cmi \
+    utils/diffing_with_keys.cmi
+utils/diffing_with_keys.cmx : \
+    utils/misc.cmx \
+    utils/diffing.cmx \
+    utils/diffing_with_keys.cmi
+utils/diffing_with_keys.cmi : \
     utils/diffing.cmi
-utils/diffing.cmi :
 utils/domainstate.cmo : \
     utils/domainstate.cmi
 utils/domainstate.cmx : \
@@ -694,6 +707,7 @@ typing/includecore.cmo : \
     typing/ident.cmi \
     typing/errortrace.cmi \
     typing/env.cmi \
+    utils/diffing_with_keys.cmi \
     typing/ctype.cmi \
     parsing/builtin_attributes.cmi \
     typing/btype.cmi \
@@ -710,6 +724,7 @@ typing/includecore.cmx : \
     typing/ident.cmx \
     typing/errortrace.cmx \
     typing/env.cmx \
+    utils/diffing_with_keys.cmx \
     typing/ctype.cmx \
     parsing/builtin_attributes.cmx \
     typing/btype.cmx \
@@ -723,7 +738,8 @@ typing/includecore.cmi : \
     parsing/location.cmi \
     typing/ident.cmi \
     typing/errortrace.cmi \
-    typing/env.cmi
+    typing/env.cmi \
+    utils/diffing_with_keys.cmi
 typing/includemod.cmo : \
     typing/types.cmi \
     typing/typedtree.cmi \

Changes

@@ -382,6 +382,11 @@ OCaml 4.13.0
 - #10232: Warning for unused record fields.
   (Leo White, review by Florian Angeletti)
 
+- #?????: Improve error messages for mismatched record and variant
+  definitions.
+  (Florian Angeletti, review by ???)
+
+
 ### Internal/compiler-libs changes:
 
 - #9243, simplify parser rules for array indexing operations

compilerlibs/Makefile.compilerlibs

@@ -45,7 +45,8 @@ UTILS = \
   utils/domainstate.cmo \
   utils/binutils.cmo \
   utils/lazy_backtrack.cmo \
-  utils/diffing.cmo
+  utils/diffing.cmo \
+  utils/diffing_with_keys.cmo
 UTILS_CMI =
 
 PARSING = \

dune

@@ -45,7 +45,7 @@
    config build_path_prefix_map misc identifiable numbers arg_helper clflags
    profile terminfo ccomp warnings consistbl strongly_connected_components
    targetint load_path int_replace_polymorphic_compare binutils local_store
-   lazy_backtrack diffing
+   lazy_backtrack diffing diffing_with_keys
 
    ;; PARSING
    location longident docstrings syntaxerr ast_helper camlinternalMenhirLib

testsuite/tests/typing-misc/records.ml

@@ -232,7 +232,7 @@ Line 1, characters 0-28:
 1 | type missing = d = { x:int }
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       The field y is only present in the original definition.
+       An extra field, y, is provided in the original definition.
 |}]
 
 type wrong_type = d = {x:float}
@@ -241,11 +241,12 @@ Line 1, characters 0-31:
 1 | type wrong_type = d = {x:float}
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       Fields do not match:
+       1. Fields do not match:
          x : int;
        is not the same as:
          x : float;
        The type int is not equal to the type float
+       2. An extra field, y, is provided in the original definition.
 |}]
 
 type mono = {foo:int}
@@ -266,5 +267,5 @@ Line 1, characters 0-30:
 1 | type perm = d = {y:int; x:int}
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       Fields number 1 have different names, x and y.
+       Fields x and y have been swapped.
 |}]

testsuite/tests/typing-misc/variant.ml

@@ -89,7 +89,7 @@ Line 3, characters 0-27:
 3 | type missing = d = X of int
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       The constructor Y is only present in the original definition.
+       An extra constructor, Y, is provided in the original definition.
 |}]
 
 type wrong_type = d = X of float
@@ -98,11 +98,12 @@ Line 1, characters 0-32:
 1 | type wrong_type = d = X of float
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       Constructors do not match:
+       1. Constructors do not match:
          X of int
        is not the same as:
          X of float
        The type int is not equal to the type float
+       2. An extra constructor, Y, is provided in the original definition.
 |}]
 
 type mono = Foo of float
@@ -123,7 +124,7 @@ Line 1, characters 0-35:
 1 | type perm = d = Y of int | X of int
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 Error: This variant or record definition does not match that of type d
-       Constructors number 1 have different names, X and Y.
+       Constructors X and Y have been swapped.
 |}]
 
 module M : sig

testsuite/tests/typing-modules/module_type_substitution.ml

@@ -147,11 +147,16 @@ Error: In this `with' constraint, the new definition of t
          type t = X of x | Y of y
        is not included in
          type t = X of int | Y of float
-       Constructors do not match:
+       1. Constructors do not match:
          X of x
        is not the same as:
          X of int
        The type x is not equal to the type int
+       2. Constructors do not match:
+         Y of y
+       is not the same as:
+         Y of float
+       The type y is not equal to the type float
 |}]
 
 (** First class module types require an identity *)