Derive scalar changes and composition laws

src/value.ml

@@ -35,7 +35,19 @@ let collection_of_list entries =
 
 let collection_to_list map = Delta_runtime.Pure_map.bindings map
 
-let equal (left : t) (right : t) = left = right
+let rec equal (left : t) (right : t) =
+  match (left, right) with
+  | VUnit, VUnit -> true
+  | VInt a, VInt b -> a = b
+  | VBool a, VBool b -> a = b
+  | VString a, VString b -> a = b
+  | VTuple a, VTuple b -> List.length a = List.length b && List.for_all2 equal a b
+  | VRecord (name_a, fields_a), VRecord (name_b, fields_b) ->
+      name_a = name_b
+      && List.length fields_a = List.length fields_b
+      && List.for_all2 (fun (label_a, value_a) (label_b, value_b) -> label_a = label_b && equal value_a value_b) fields_a fields_b
+  | VCollection map_a, VCollection map_b -> Delta_runtime.Pure_map.equal equal map_a map_b
+  | _ -> false
 
 let field record label =
   match record with