refactor

Author: zth

compiler/ml/ctype.ml

@@ -53,8 +53,9 @@ open Btype
 *)
 
 (**** Errors ****)
+type type_pairs = (type_expr * type_expr) list
 
-exception Unify of (type_expr * type_expr) list
+exception Unify of type_pairs
 
 exception Tags of label * label
 
@@ -100,11 +101,7 @@ type subtype_context =
       issues: Record_coercion.record_field_subtype_violation list;
     }
 
-exception
-  Subtype of
-    (type_expr * type_expr) list
-    * (type_expr * type_expr) list
-    * subtype_context option
+exception Subtype of type_pairs * type_pairs * subtype_context option
 
 exception Cannot_expand
 
@@ -113,7 +110,7 @@ exception Cannot_apply
 exception Recursive_abbrev
 
 (* GADT: recursive abbrevs can appear as a result of local constraints *)
-exception Unification_recursive_abbrev of (type_expr * type_expr) list
+exception Unification_recursive_abbrev of type_pairs
 
 (**** Type level management ****)
 

compiler/ml/ctype.mli

@@ -49,17 +49,14 @@ type subtype_context =
       issues: Record_coercion.record_field_subtype_violation list;
     }
 
-exception Unify of (type_expr * type_expr) list
+type type_pairs = (type_expr * type_expr) list
+exception Unify of type_pairs
 exception Tags of label * label
-exception
-  Subtype of
-    (type_expr * type_expr) list
-    * (type_expr * type_expr) list
-    * subtype_context option
+exception Subtype of type_pairs * type_pairs * subtype_context option
 exception Cannot_expand
 exception Cannot_apply
 exception Recursive_abbrev
-exception Unification_recursive_abbrev of (type_expr * type_expr) list
+exception Unification_recursive_abbrev of type_pairs
 
 val init_def : int -> unit
 (* Set the initial variable level *)

compiler/ml/printtyp.mli

@@ -94,9 +94,9 @@ val super_report_unification_error :
 val report_subtyping_error :
   formatter ->
   Env.t ->
-  (type_expr * type_expr) list ->
+  Ctype.type_pairs ->
   string ->
-  (type_expr * type_expr) list ->
+  Ctype.type_pairs ->
   Ctype.subtype_context option ->
   unit
 val report_ambiguous_type_error :

compiler/ml/typecore.ml

@@ -51,9 +51,7 @@ type error =
   | Private_type of type_expr
   | Private_label of Longident.t * type_expr
   | Not_subtype of
-      (type_expr * type_expr) list
-      * (type_expr * type_expr) list
-      * Ctype.subtype_context option
+      Ctype.type_pairs * Ctype.type_pairs * Ctype.subtype_context option
   | Too_many_arguments of bool * type_expr
   | Abstract_wrong_label of Noloc.arg_label * type_expr
   | Scoping_let_module of string * type_expr

compiler/ml/typecore.mli

@@ -76,9 +76,7 @@ type error =
   | Private_type of type_expr
   | Private_label of Longident.t * type_expr
   | Not_subtype of
-      (type_expr * type_expr) list
-      * (type_expr * type_expr) list
-      * Ctype.subtype_context option
+      Ctype.type_pairs * Ctype.type_pairs * Ctype.subtype_context option
   | Too_many_arguments of bool * type_expr
   | Abstract_wrong_label of Noloc.arg_label * type_expr
   | Scoping_let_module of string * type_expr