[syntax_tools] Let erl_syntax:concrete() accept the F/A syntax

Note: `arity_qualifier` nodes are recognized. This is to follow The
Erlang Parser when it comes to wild attributes: both {F, A} and F/A
are recognized, which makes it possible to turn wild attributes into
recognized attributes without at the same time making it impossible to
compile files using the new syntax with the old version of the Erlang
Compiler.

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/syntax_tools/src/erl_syntax.erl b/lib/syntax_tools/src/erl_syntax.erl
index f7819c2662..2576d227df 100644
--- a/lib/syntax_tools/src/erl_syntax.erl
+++ b/lib/syntax_tools/src/erl_syntax.erl
@@ -6134,6 +6134,13 @@ abstract_tail(H, T) ->
 %% {@link char/1} function to explicitly create an abstract
 %% character.)
 %%
+%% Note: `arity_qualifier' nodes are recognized. This is to follow The
+%% Erlang Parser when it comes to wild attributes: both {F, A} and F/A
+%% are recognized, which makes it possible to turn wild attributes
+%% into recognized attributes without at the same time making it
+%% impossible to compile files using the new syntax with the old
+%% version of the Erlang Compiler.
+%%
 %% @see abstract/1
 %% @see is_literal/1
 %% @see char/1
@@ -6175,6 +6182,20 @@ concrete(Node) ->
 					   {value, concrete(F), []}
 				   end, [], true),
 	    B;
+        arity_qualifier ->
+            A = erl_syntax:arity_qualifier_argument(Node),
+            case erl_syntax:type(A) of
+                integer ->
+                    F = erl_syntax:arity_qualifier_body(Node),
+                    case erl_syntax:type(F) of
+                        atom ->
+                            {F, A};
+                        _ ->
+                            erlang:error({badarg, Node})
+                    end;
+                _ ->
+                    erlang:error({badarg, Node})
+            end;
         _ ->
 	    erlang:error({badarg, Node})
     end.