Support nested record field access without parentheses

Original patch from YAMASHINA Hio posted to erlang-patches@
on Tue Jun 12 11:27:53 CEST 2007:
http://www.erlang.org/pipermail/erlang-patches/2007-June/000182.html
http://fleur.hio.jp/pub/erlang/record2.patch

Only had to do minor changes to port the patch to the
current R14A development tree.

Also added compiler/record_SUITE:nested_access/2 to test
nested record access with or without parentheses.

With this change the following will work.

-record(nrec0, {name = <<"nested0">>}).
-record(nrec1, {name = <<"nested1">>, nrec0=#nrec0{}}).
-record(nrec2, {name = <<"nested2">>, nrec1=#nrec1{}}).

nested_access() ->
    N0 = #nrec0{},
    N1 = #nrec1{},
    N2 = #nrec2{},
    <<"nested0">> = N0#nrec0.name,
    <<"nested1">> = N1#nrec1.name,
    <<"nested2">> = N2#nrec2.name,
    <<"nested0">> = N1#nrec1.nrec0#nrec0.name,
    <<"nested0">> = N2#nrec2.nrec1#nrec1.nrec0#nrec0.name,
    <<"nested1">> = N2#nrec2.nrec1#nrec1.name,
    <<"nested0">> = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0.name,

    N1a = N2#nrec2.nrec1#nrec1{name = <<"nested1a">>},
    <<"nested1a">> = N1a#nrec1.name,

    N2a = N2#nrec2.nrec1#nrec1.nrec0#nrec0{name = <<"nested0a">>},
    N2b = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0{name = <<"nested0a">>},
    <<"nested0a">> = N2a#nrec0.name,
    N2a = N2b,
    ok.

Signed-off-by: Tuncer Ayaz <[email protected]>

2 files changed, 36 insertions, 7 deletions

diff --git a/lib/compiler/test/record_SUITE.erl b/lib/compiler/test/record_SUITE.erl
index bd2ffd7f65..f26ff769c7 100644
--- a/lib/compiler/test/record_SUITE.erl
+++ b/lib/compiler/test/record_SUITE.erl
@@ -1,19 +1,19 @@
 %%
 %% %CopyrightBegin%
-%% 
-%% Copyright Ericsson AB 2003-2009. All Rights Reserved.
-%% 
+%%
+%% Copyright Ericsson AB 2003-2010. All Rights Reserved.
+%%
 %% The contents of this file are subject to the Erlang Public License,
 %% Version 1.1, (the "License"); you may not use this file except in
 %% compliance with the License. You should have received a copy of the
 %% Erlang Public License along with this software. If not, it can be
 %% retrieved online at http://www.erlang.org/.
-%% 
+%%
 %% Software distributed under the License is distributed on an "AS IS"
 %% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 %% the License for the specific language governing rights and limitations
 %% under the License.
-%% 
+%%
 %% %CopyrightEnd%
 %%
 %%% Purpose : Test records.
@@ -24,7 +24,7 @@
 
 -export([all/1,init_per_testcase/2,fin_per_testcase/2,
 	 errors/1,record_test_2/1,record_test_3/1,record_access_in_guards/1,
-	 guard_opt/1,eval_once/1,foobar/1,missing_test_heap/1]).
+	 guard_opt/1,eval_once/1,foobar/1,missing_test_heap/1, nested_access/1]).
 
 init_per_testcase(_Case, Config) ->
     ?line Dog = test_server:timetrap(test_server:minutes(2)),
@@ -38,7 +38,7 @@ fin_per_testcase(_Case, Config) ->
 all(suite) ->
     test_lib:recompile(?MODULE),
     [errors,record_test_2,record_test_3,record_access_in_guards,
-     guard_opt,eval_once,foobar,missing_test_heap].
+     guard_opt,eval_once,foobar,missing_test_heap,nested_access].
 
 -record(foo, {a,b,c,d}).
 -record(bar, {a,b,c,d}).
@@ -522,4 +522,29 @@ missing_test_heap_1(A = #foo_rec {foo_1 = _B,
   	       foo_3 = C + 1,
   	       foo_2 = D + 1}.
 
+-record(nrec0, {name = <<"nested0">>}).
+-record(nrec1, {name = <<"nested1">>, nrec0=#nrec0{}}).
+-record(nrec2, {name = <<"nested2">>, nrec1=#nrec1{}}).
+
+nested_access(Config) when is_list(Config) ->
+    N0 = #nrec0{},
+    N1 = #nrec1{},
+    N2 = #nrec2{},
+    ?line <<"nested0">> = N0#nrec0.name,
+    ?line <<"nested1">> = N1#nrec1.name,
+    ?line <<"nested2">> = N2#nrec2.name,
+    ?line <<"nested0">> = N1#nrec1.nrec0#nrec0.name,
+    ?line <<"nested0">> = N2#nrec2.nrec1#nrec1.nrec0#nrec0.name,
+    ?line <<"nested1">> = N2#nrec2.nrec1#nrec1.name,
+    ?line <<"nested0">> = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0.name,
+
+    N1a = N2#nrec2.nrec1#nrec1{name = <<"nested1a">>},
+    ?line <<"nested1a">> = N1a#nrec1.name,
+
+    N2a = N2#nrec2.nrec1#nrec1.nrec0#nrec0{name = <<"nested0a">>},
+    N2b = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0{name = <<"nested0a">>},
+    ?line <<"nested0a">> = N2a#nrec0.name,
+    ?line N2a = N2b,
+    ok.
+
 id(I) -> I.
diff --git a/lib/stdlib/src/erl_parse.yrl b/lib/stdlib/src/erl_parse.yrl
index 7145cf13fd..69807aad83 100644
--- a/lib/stdlib/src/erl_parse.yrl
+++ b/lib/stdlib/src/erl_parse.yrl
@@ -335,6 +335,10 @@ record_expr -> expr_max '#' atom '.' atom :
 	{record_field,?line('$2'),'$1',element(3, '$3'),'$5'}.
 record_expr -> expr_max '#' atom record_tuple :
 	{record,?line('$2'),'$1',element(3, '$3'),'$4'}.
+record_expr -> record_expr '#' atom '.' atom :
+	{record_field,?line('$2'),'$1',element(3, '$3'),'$5'}.
+record_expr -> record_expr '#' atom record_tuple :
+	{record,?line('$2'),'$1',element(3, '$3'),'$4'}.
 
 record_tuple -> '{' '}' : [].
 record_tuple -> '{' record_fields '}' : '$2'.