Remove Type and Spec, backport list comprehensions, so R12B-5 can compile

src/pg2_backport.erl

@@ -30,18 +30,12 @@
 %%% Exported functions
 %%%
 
--spec start_link() -> {'ok', pid()} | {'error', term()}.
-
 start_link() ->
     gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
 
--spec start() -> {'ok', pid()} | {'error', term()}.
-
 start() ->
     ensure_started().
 
--spec create(term()) -> 'ok'.
-
 create(Name) ->
     ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
@@ -55,10 +49,6 @@ create(Name) ->
             ok
     end.
 
--type name() :: term().
-
--spec delete(name()) -> 'ok'.
-
 delete(Name) ->
     ensure_started(),
     global:trans({{?MODULE, Name}, self()},
@@ -67,8 +57,6 @@ delete(Name) ->
                  end),
     ok.
 
--spec join(name(), pid()) -> 'ok' | {'error', {'no_such_group', term()}}.
-
 join(Name, Pid) when is_pid(Pid) ->
     ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
@@ -83,8 +71,6 @@ join(Name, Pid) when is_pid(Pid) ->
             ok
     end.
 
--spec leave(name(), pid()) -> 'ok' | {'error', {'no_such_group', name()}}.
-
 leave(Name, Pid) when is_pid(Pid) ->
     ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
@@ -99,10 +85,6 @@ leave(Name, Pid) when is_pid(Pid) ->
             ok
     end.
 
--type get_members_ret() :: [pid()] | {'error', {'no_such_group', name()}}.
-
--spec get_members(name()) -> get_members_ret().
-   
 get_members(Name) ->
     ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
@@ -112,8 +94,6 @@ get_members(Name) ->
             {error, {no_such_group, Name}}
     end.
 
--spec get_local_members(name()) -> get_members_ret().
-
 get_local_members(Name) ->
     ensure_started(),
     case ets:member(pg2_table, {group, Name}) of
@@ -123,16 +103,10 @@ get_local_members(Name) ->
             {error, {no_such_group, Name}}
     end.
 
--spec which_groups() -> [name()].
-
 which_groups() ->
     ensure_started(),
     all_groups().
 
--type gcp_error_reason() :: {'no_process', term()} | {'no_such_group', term()}.
-
--spec get_closest_pid(term()) -> pid() | {'error', gcp_error_reason()}.
-
 get_closest_pid(Name) ->
     case get_local_members(Name) of
         [Pid] ->
@@ -157,8 +131,6 @@ get_closest_pid(Name) ->
 
 -record(state, {}).
 
--spec init([]) -> {'ok', #state{}}.
-
 init([]) ->
     Ns = nodes(),
     net_kernel:monitor_nodes(true),
@@ -169,14 +141,6 @@ init([]) ->
     pg2_table = ets:new(pg2_table, [ordered_set, protected, named_table]),
     {ok, #state{}}.
 
--type call() :: {'create', name()}
-              | {'delete', name()}
-              | {'join', name(), pid()}
-              | {'leave', name(), pid()}.
-
--spec handle_call(call(), _, #state{}) -> 
-        {'reply', 'ok', #state{}}.
-
 handle_call({create, Name}, _From, S) ->
     assure_group(Name),
     {reply, ok, S};
@@ -195,12 +159,6 @@ handle_call(Request, From, S) ->
                              [Request, From]),
     {noreply, S}.
 
--type all_members() :: [[name(),...]].
--type cast() :: {'exchange', node(), all_members()}
-              | {'del_member', name(), pid()}.
-
--spec handle_cast(cast(), #state{}) -> {'noreply', #state{}}.
-
 handle_cast({exchange, _Node, List}, S) ->
     store(List),
     {noreply, S};
@@ -208,8 +166,6 @@ handle_cast(_, S) ->
     %% Ignore {del_member, Name, Pid}.
     {noreply, S}.
 
--spec handle_info(tuple(), #state{}) -> {'noreply', #state{}}.
-
 handle_info({'DOWN', MonitorRef, process, _Pid, _Info}, S) ->
     member_died(MonitorRef),
     {noreply, S};
@@ -222,8 +178,6 @@ handle_info({new_pg2, Node}, S) ->
 handle_info(_, S) ->
     {noreply, S}.
 
--spec terminate(term(), #state{}) -> 'ok'.
-
 terminate(_Reason, _S) ->
     true = ets:delete(pg2_table),
     ok.
@@ -289,8 +243,9 @@ join_group(Name, Pid) ->
     try _ = ets:update_counter(pg2_table, Member_Name_Pid, {2, +1})
     catch _:_ ->
             true = ets:insert(pg2_table, {Member_Name_Pid, 1}),
-            _ = [ets:insert(pg2_table, {{local_member, Name, Pid}}) ||
+            _ = [ets:insert(pg2_table, {{local_member, Name, PidX}}) ||
-                    node(Pid) =:= node()],
+                    PidX <- [Pid],
+                    node(PidX) =:= node()],
             true = ets:insert(pg2_table, {{pid, Pid, Name}})
     end.
 
@@ -301,8 +256,9 @@ leave_group(Name, Pid) ->
             if 
                 N =:= 0 ->
                     true = ets:delete(pg2_table, {pid, Pid, Name}),
-                    _ = [ets:delete(pg2_table, {local_member, Name, Pid}) ||
+                    _ = [ets:delete(pg2_table, {local_member, Name, PidX}) ||
-                            node(Pid) =:= node()],
+                            PidX <- [Pid],
+                            node(PidX) =:= node()],
                     true = ets:delete(pg2_table, Member_Name_Pid);
                 true ->
                     ok