Make 'return' a reserved (but invalid) keyword

Fix bug with missing source location for function applications

src/aeso_ast_infer_types.erl

@@ -783,7 +783,8 @@ check_type(_Env, Type = {uvar, _, _}, Arity) ->
     ensure_base_type(Type, Arity),
     Type;
 check_type(_Env, {args_t, Ann, Ts}, _) ->
-    type_error({new_tuple_syntax, Ann, Ts}).
+    type_error({new_tuple_syntax, Ann, Ts}),
+    {tuple_t, Ann, Ts}.
 
 ensure_base_type(Type, Arity) ->
     [ type_error({wrong_type_arguments, Type, Arity, 0}) || Arity /= 0 ],
@@ -1155,8 +1156,6 @@ infer_expr(Env, {typed, As, Body, Type}) ->
     {typed, _, NewBody, NewType} = check_expr(Env, Body, Type1),
     {typed, As, NewBody, NewType};
 infer_expr(Env, {app, Ann, Fun, Args0}) ->
-    %% TODO: fix parser to give proper annotation for normal applications!
-    FunAnn     = aeso_syntax:get_ann(Fun),
     NamedArgs  = [ Arg || Arg = {named_arg, _, _, _} <- Args0 ],
     Args       = Args0 -- NamedArgs,
     case aeso_syntax:get_ann(format, Ann) of
@@ -1165,15 +1164,15 @@ infer_expr(Env, {app, Ann, Fun, Args0}) ->
         prefix ->
             infer_op(Env, Ann, Fun, Args, fun infer_prefix/1);
         _ ->
-            NamedArgsVar = fresh_uvar(FunAnn),
+            NamedArgsVar = fresh_uvar(Ann),
             NamedArgs1 = [ infer_named_arg(Env, NamedArgsVar, Arg) || Arg <- NamedArgs ],
             %% TODO: named args constraints
             NewFun={typed, _, _, FunType} = infer_expr(Env, Fun),
             NewArgs = [infer_expr(Env, A) || A <- Args],
             ArgTypes = [T || {typed, _, _, T} <- NewArgs],
-            ResultType = fresh_uvar(FunAnn),
+            ResultType = fresh_uvar(Ann),
             unify(Env, FunType, {fun_t, [], NamedArgsVar, ArgTypes, ResultType}, {infer_app, Fun, Args, FunType, ArgTypes}),
-            {typed, FunAnn, {app, Ann, NewFun, NamedArgs1 ++ NewArgs}, dereference(ResultType)}
+            {typed, Ann, {app, Ann, NewFun, NamedArgs1 ++ NewArgs}, dereference(ResultType)}
     end;
 infer_expr(Env, {'if', Attrs, Cond, Then, Else}) ->
     NewCond = check_expr(Env, Cond, {id, Attrs, "bool"}),

src/aeso_parse_lib.erl

@@ -355,6 +355,7 @@ unexpected_token_error(Ts, Expect, T) ->
               {con, _, X}   when ExpectId               -> io_lib:format(" Did you mean ~s?", [mk_lower(X)]);
               {qcon, _, Xs} when ExpectCon              -> io_lib:format(" Did you mean ~s?", [lists:last(Xs)]);
               {qid, _,  Xs} when ExpectId               -> io_lib:format(" Did you mean ~s?", [lists:last(Xs)]);
+              {return, _} -> " [Polite reminder that Sophia is not JavaScript]";
               _ -> ""
           end,
     mk_error(Ts, io_lib:format("Unexpected ~s.~s", [describe(T), Fix])).

src/aeso_parser.erl

@@ -312,7 +312,7 @@ map_key(Key, {ok, {_, Val}}) -> {map_key, Key, Val}.
 
 elim(E, [])                              -> E;
 elim(E, [{proj, Ann, P} | Es])           -> elim({proj, Ann, E, P}, Es);
-elim(E, [{app, Ann, Args} | Es])         -> elim({app, Ann, E, Args}, Es);
+elim(E, [{app, _Ann, Args} | Es])        -> elim({app, aeso_syntax:get_ann(E), E, Args}, Es);
 elim(E, [{rec_upd, Ann, Flds} | Es])     -> elim(record_update(Ann, E, Flds), Es);
 elim(E, [{map_get, Ann, Key} | Es])      -> elim({map_get, Ann, E, Key}, Es);
 elim(E, [{map_get, Ann, Key, Val} | Es]) -> elim({map_get, Ann, E, Key, Val}, Es).

src/aeso_scan.erl

@@ -37,7 +37,8 @@ lexer() ->
         , {"[^/*]+|[/*]", skip()} ],
 
     Keywords = ["contract", "include", "let", "switch", "type", "record", "datatype", "if", "elif", "else", "function",
-                "stateful", "payable", "true", "false", "mod", "public", "entrypoint", "private", "indexed", "namespace"],
+                "stateful", "payable", "true", "false", "mod", "public", "entrypoint", "private", "indexed", "namespace",
+                "return"],
     KW = string:join(Keywords, "|"),
 
     Rules =

test/aeso_compiler_tests.erl

@@ -301,7 +301,14 @@ failing_contracts() ->
         <<?Pos(54, 5)
           "Let binding at line 54, column 5 must be followed by an expression">>,
         <<?Pos(58, 5)
-          "Let binding at line 58, column 5 must be followed by an expression">>])
+          "Let binding at line 58, column 5 must be followed by an expression">>,
+        <<?Pos(63, 5)
+          "Cannot unify int\n"
+          "         and bool\n"
+          "when checking the type of the expression at line 63, column 5\n"
+          "  id(n) : int\n"
+          "against the expected type\n"
+          "  bool">>])
     , ?TYPE_ERROR(init_type_error,
        [<<?Pos(7, 3)
           "Cannot unify string\n"

test/contracts/type_errors.aes

@@ -57,3 +57,8 @@ contract Test =
     let f() = 0
     let g() = f()
 
+  function id(x : 'a) : 'a = x
+
+  entrypoint wrong_return(n : int) : bool =
+    id(n)
+