src/aeso_ast_infer_types.erl

@@ -87,7 +87,9 @@
 -type byte_constraint() :: {is_bytes, utype()}
                          | {add_bytes, aeso_syntax:ann(), concat | split, utype(), utype(), utype()}.
 
--type constraint() :: named_argument_constraint() | field_constraint() | byte_constraint().
+-type aens_resolve_constraint() :: {aens_resolve_type, utype()}.
+
+-type constraint() :: named_argument_constraint() | field_constraint() | byte_constraint() | aens_resolve_constraint().
 
 -record(field_info,
     { ann      :: aeso_syntax:ann()
@@ -1818,6 +1820,8 @@ infer_expr(Env, {app, Ann, Fun, Args0} = App) ->
             ResultType = fresh_uvar(Ann),
             unify(Env, FunType, {fun_t, [], NamedArgsVar, ArgTypes, GeneralResultType}, When),
             when_warning(warn_negative_spend, fun() -> warn_potential_negative_spend(Ann, NewFun1, NewArgs) end),
+            [ add_constraint({aens_resolve_type, GeneralResultType})
+              || element(3, Fun) =:= ["AENS", "resolve"] ],
             add_constraint(
               #dependent_type_constraint{ named_args_t = NamedArgsVar,
                                           named_args   = NamedArgs1,
@@ -2338,11 +2342,15 @@ destroy_and_report_unsolved_constraints(Env) ->
                            (#named_argument_constraint{}) -> true;
                            (_)                            -> false
                         end, OtherCs2),
-    {BytesCs, []} =
+    {BytesCs, OtherCs4} =
         lists:partition(fun({is_bytes, _})              -> true;
                            ({add_bytes, _, _, _, _, _}) -> true;
                            (_)                          -> false
                         end, OtherCs3),
+    {AensResolveCs, []} =
+        lists:partition(fun({aens_resolve_type, _}) -> true;
+                           (_)                      -> false
+                        end, OtherCs4),
 
     Unsolved = [ S || S <- [ solve_constraint(Env, dereference_deep(C)) || C <- NamedArgCs ],
                       S == unsolved ],
@@ -2360,6 +2368,7 @@ destroy_and_report_unsolved_constraints(Env) ->
     check_record_create_constraints(Env, CreateCs),
     check_is_contract_constraints(Env, ContractCs),
     check_bytes_constraints(Env, BytesCs),
+    check_aens_resolve_constraints(Env, AensResolveCs),
 
     destroy_constraints().
 
@@ -2489,6 +2498,21 @@ check_bytes_constraint(Env, {add_bytes, Ann, Fun, A0, B0, C0}) ->
         _ -> type_error({unsolved_bytes_constraint, Ann, Fun, A, B, C})
     end.
 
+check_aens_resolve_constraints(_Env, []) ->
+    ok;
+check_aens_resolve_constraints(Env, [{aens_resolve_type, Type} | Rest]) ->
+    Type1 = unfold_types_in_type(Env, instantiate(Type)),
+    {app_t, _, {id, _, "option"}, [Type2]} = Type1,
+    case Type2 of
+        {id, _, "string"} -> ok;
+        {id, _, "address"} -> ok;
+        {con, _, _} -> ok;
+        {app_t, _, {id, _, "oracle"}, [_, _]} -> ok;
+        {app_t, _, {id, _, "oracle_query"}, [_, _]} -> ok;
+        _ -> type_error({invalid_aens_resolve_type, aeso_syntax:get_ann(Type), Type2})
+    end,
+    check_aens_resolve_constraints(Env, Rest).
+
 %% -- Field constraints --
 
 check_record_create_constraints(_, []) -> ok;
@@ -3558,6 +3582,12 @@ mk_error({higher_order_entrypoint, Ann, {id, _, Name}, Thing}) ->
     Msg = io_lib:format("The ~sof entrypoint `~s` ~s",
                         [ThingS, Name, Bad]),
     mk_t_err(pos(Ann), Msg);
+mk_error({invalid_aens_resolve_type, Ann, T}) ->
+    Msg = io_lib:format("Invalid return type of `AENS.resolve`:\n"
+                        "~s`\n"
+                        "It must be a `string` or a pubkey type (`address`, `oracle`, etc)",
+                        [pp_type("  `", T)]),
+    mk_t_err(pos(Ann), Msg);
 mk_error(Err) ->
     Msg = io_lib:format("Unknown error: ~p", [Err]),
     mk_t_err(pos(0, 0), Msg).

src/aeso_ast_to_fcode.erl

@@ -551,7 +551,6 @@ expr_to_fcode(Env, Type, {qid, Ann, X}) ->
         {builtin_u, B = aens_resolve, Ar} ->
             {fun_t, _, _, _, ResType} = Type,
             AensType = type_to_fcode(Env, ResType),
-            validate_aens_resolve_type(Ann, ResType, AensType),
             TypeArgs = [{lit, {typerep, AensType}}],
             {builtin_u, B, Ar, TypeArgs};
         {builtin_u, B = bytes_split, Ar} ->
@@ -811,16 +810,6 @@ validate_oracle_type(Ann, Type, QType, RType) ->
     ensure_first_order(RType, {invalid_oracle_type, higher_order, response, Ann, Type}),
     ok.
 
-validate_aens_resolve_type(Ann, {app_t, _, _, [Type]}, {variant, [[], [FType]]}) ->
-    case FType of
-        string         -> ok;
-        address        -> ok;
-        contract       -> ok;
-        {oracle, _, _} -> ok;
-        oracle_query   -> ok;
-        _              -> fcode_error({invalid_aens_resolve_type, Ann, Type})
-    end.
-
 ensure_monomorphic(Type, Err) ->
     case is_monomorphic(Type) of
         true  -> ok;

src/aeso_code_errors.erl

@@ -10,12 +10,6 @@
 
 -export([format/1, pos/1]).
 
-format({invalid_aens_resolve_type, Ann, T}) ->
-    Msg = io_lib:format("Invalid return type of AENS.resolve:\n"
-                        "~s\n"
-                        "It must be a string or a pubkey type (address, oracle, etc).",
-                        [pp_type(2, T)]),
-    mk_err(pos(Ann), Msg);
 format({invalid_oracle_type, Why, What, Ann, Type}) ->
     WhyS = case Why of higher_order -> "higher-order (contain function types)";
                        polymorphic  -> "polymorphic (contain type variables)" end,

test/aeso_compiler_tests.erl

@@ -1058,6 +1058,18 @@ failing_contracts() ->
                      "  `(int) => int`\n"
                      "of entrypoint `add` is higher-order (contains function types)">>
                   ])
+    , ?TYPE_ERROR(polymorphic_aens_resolve,
+                  [<<?Pos(4,5)
+                     "Invalid return type of `AENS.resolve`:\n"
+                     "  `'a`\n"
+                     "It must be a `string` or a pubkey type (`address`, `oracle`, etc)">>
+                  ])
+    , ?TYPE_ERROR(bad_aens_resolve,
+                  [<<?Pos(6,5)
+                     "Invalid return type of `AENS.resolve`:\n"
+                     "  `list(int)`\n"
+                     "It must be a `string` or a pubkey type (`address`, `oracle`, etc)">>
+                  ])
     ].
 
 -define(Path(File), "code_errors/" ??File).
@@ -1066,15 +1078,7 @@ failing_contracts() ->
 -define(FATE_ERR(File, Line, Col, Err), {?Path(File), ?Msg(File, Line, Col, Err)}).
 
 failing_code_gen_contracts() ->
-    [ ?FATE_ERR(polymorphic_aens_resolve, 4, 5,
-            "Invalid return type of AENS.resolve:\n"
-            "  'a\n"
-            "It must be a string or a pubkey type (address, oracle, etc).")
-    , ?FATE_ERR(bad_aens_resolve, 6, 5,
-            "Invalid return type of AENS.resolve:\n"
-            "  list(int)\n"
-            "It must be a string or a pubkey type (address, oracle, etc).")
-    , ?FATE_ERR(polymorphic_query_type, 3, 5,
+    [ ?FATE_ERR(polymorphic_query_type, 3, 5,
             "Invalid oracle type\n"
             "  oracle('a, 'b)\n"
             "The query type must not be polymorphic (contain type variables).")