Yet another refactoring proposal

Author: sabiwara

lib/elixir/src/elixir_quote.erl

@@ -164,15 +164,7 @@ do_escape(BitString, _) when is_bitstring(BitString) ->
   end;
 
 do_escape(Map, Q) when is_map(Map) ->
-  TT =
-    [case do_quote_map_value(V, Q) of
-      {ok, QV} ->
-        {do_quote(K, Q), QV};
-      {error, Ref} ->
-        argument_error(<<('Elixir.Kernel':inspect(Map, []))/binary, " contains a reference (",
-                         ('Elixir.Kernel':inspect(Ref, []))/binary, ") and therefore it cannot be escaped ",
-                         "(it must be defined within a function instead). ", (bad_escape_hint())/binary>>)
-     end || {K, V} <- lists:sort(maps:to_list(Map))],
+  TT = [escape_map_key_value(K, V, Map, Q) || {K, V} <- lists:sort(maps:to_list(Map))],
   {'%{}', [], TT};
 
 do_escape([], _) ->
@@ -206,16 +198,26 @@ do_escape(Fun, _) when is_function(Fun) ->
 do_escape(Other, _) ->
   bad_escape(Other).
 
-do_quote_map_value(Ref, _Q) when is_reference(Ref) -> {error, Ref};
-do_quote_map_value(Tuple, Q) when is_tuple(Tuple) -> do_quote_map_value_tuple(Tuple, Q, 1);
-do_quote_map_value(Value, Q) -> {ok, do_quote(Value, Q)}.
+escape_map_key_value(K, V, Map, Q) ->
+  MaybeRef = if
+    is_reference(V) -> V;
+    is_tuple(V) -> find_tuple_ref(V, 1);
+    true -> nil
+  end,
+  if
+    is_reference(MaybeRef) ->
+      argument_error(<<('Elixir.Kernel':inspect(Map, []))/binary, " contains a reference (",
+                        ('Elixir.Kernel':inspect(MaybeRef, []))/binary, ") and therefore it cannot be escaped ",
+                        "(it must be defined within a function instead). ", (bad_escape_hint())/binary>>);
+    true ->
+      {do_quote(K, Q), do_quote(V, Q)}
+    end.
 
-do_quote_map_value_tuple(Tuple, Q, Index) when Index > tuple_size(Tuple) ->
-  {ok, do_quote(Tuple, Q)};
-do_quote_map_value_tuple(Tuple, Q, Index) ->
+find_tuple_ref(Tuple, Index) when Index > tuple_size(Tuple) -> nil;
+find_tuple_ref(Tuple, Index) ->
   case element(Index, Tuple) of
-    Ref when is_reference(Ref) -> {error, Ref};
-    _ -> do_quote_map_value_tuple(Tuple, Q, Index + 1)
+    Ref when is_reference(Ref) -> Ref;
+    _ -> find_tuple_ref(Tuple, Index + 1)
   end.
 
 bad_escape(Arg) ->