Refactor mochi#184 for less redundant code

rebar.config

@@ -1,9 +1,9 @@
 % -*- mode: erlang -*-
 {erl_opts, [debug_info,
-            {platform_define, "R15", 'gen_tcp_r15b_workaround'},
-            {platform_define, "(R14|R15|R16B-)", 'crypto_compatibility'},
-            {platform_define, "(R14|R15|R16B|17)", 'rand_mod_unavailable'},
-            {platform_define, "(17|18|19)", 'map_available'}]}.
+            {platform_define, "^R15", 'gen_tcp_r15b_workaround'},
+            {platform_define, "^(R14|R15|R16B-)", 'crypto_compatibility'},
+            {platform_define, "^(R14|R15|R16B|17)", 'rand_mod_unavailable'},
+            {platform_define, "^(R14|R15|R16)", 'map_unavailable'}]}.
 {cover_enabled, true}.
 {eunit_opts, [verbose, {report,{eunit_surefire,[{dir,"."}]}}]}.
 {dialyzer_opts, [{warnings, [no_return,

src/mochijson2.erl

@@ -82,6 +82,12 @@
 -define(IS_WHITESPACE(C),
         (C =:= $\s orelse C =:= $\t orelse C =:= $\r orelse C =:= $\n)).
 
+-ifdef(map_unavailable).
+-define(IS_MAP(_), false).
+-else.
+-define(IS_MAP(X), is_map(X)).
+-endif.
+
 %% @type json_string() = atom | binary()
 %% @type json_number() = integer() | float()
 %% @type json_array() = [json_term()]
@@ -150,7 +156,6 @@ parse_decoder_options([{format, Format} | Rest], State)
     parse_decoder_options(Rest, State#decoder{object_hook=Format}).
 
 
--ifdef(map_available).
 json_encode(true, _State) ->
     <<"true">>;
 json_encode(false, _State) ->
@@ -177,48 +182,14 @@ json_encode(Array, State) when is_list(Array) ->
     json_encode_array(Array, State);
 json_encode({array, Array}, State) when is_list(Array) ->
     json_encode_array(Array, State);
-json_encode(M, State) when is_map(M) ->
+json_encode(M, State) when ?IS_MAP(M) ->
     json_encode_map(M, State);
 json_encode({json, IoList}, _State) ->
     IoList;
 json_encode(Bad, #encoder{handler=null}) ->
     exit({json_encode, {bad_term, Bad}});
 json_encode(Bad, State=#encoder{handler=Handler}) ->
     json_encode(Handler(Bad), State).
--else.
-json_encode(true, _State) ->
-    <<"true">>;
-json_encode(false, _State) ->
-    <<"false">>;
-json_encode(null, _State) ->
-    <<"null">>;
-json_encode(I, _State) when is_integer(I) ->
-    integer_to_list(I);
-json_encode(F, _State) when is_float(F) ->
-    mochinum:digits(F);
-json_encode(S, State) when is_binary(S); is_atom(S) ->
-    json_encode_string(S, State);
-json_encode([{K, _}|_] = Props, State) when (K =/= struct andalso
-                                             K =/= array andalso
-                                             K =/= json) ->
-    json_encode_proplist(Props, State);
-json_encode({struct, Props}, State) when is_list(Props) ->
-    json_encode_proplist(Props, State);
-json_encode({Props}, State) when is_list(Props) ->
-    json_encode_proplist(Props, State);
-json_encode({}, State) ->
-    json_encode_proplist([], State);
-json_encode(Array, State) when is_list(Array) ->
-    json_encode_array(Array, State);
-json_encode({array, Array}, State) when is_list(Array) ->
-    json_encode_array(Array, State);
-json_encode({json, IoList}, _State) ->
-    IoList;
-json_encode(Bad, #encoder{handler=null}) ->
-    exit({json_encode, {bad_term, Bad}});
-json_encode(Bad, State=#encoder{handler=Handler}) ->
-    json_encode(Handler(Bad), State).
--endif.
 
 json_encode_array([], _State) ->
     <<"[]">>;
@@ -240,7 +211,11 @@ json_encode_proplist(Props, State) ->
     [$, | Acc1] = lists:foldl(F, "{", Props),
     lists:reverse([$\} | Acc1]).
 
--ifdef(map_available).
+-ifdef(map_unavailable).
+json_encode_map(Bad, _State) ->
+  %% IS_MAP definition guarantees that this branch is dead
+  exit({json_encode, {bad_term, Bad}}).
+-else.
 json_encode_map(Map, _State) when map_size(Map) =:= 0 ->
     <<"{}">>;
 json_encode_map(Map, State) ->
@@ -990,11 +965,12 @@ utf8_non_character_test_() ->
     [{"roundtrip escaped", ?_assertEqual(S, decode(encode(S)))},
      {"roundtrip utf8", ?_assertEqual(S, decode((encoder([{utf8, true}]))(S)))}].
 
-% iolist_to_binary(mochijson2:encode(#{a => 1, b => #{ c => 2}})).
--ifdef(map_available).
+-ifndef(map_unavailable).
+
 encode_map_test() ->
     M = <<"{\"a\":1,\"b\":{\"c\":2}}">>,
     ?assertEqual(M, iolist_to_binary(encode(#{a => 1, b => #{ c => 2}}))).
+
 encode_empty_map_test() ->
     ?assertEqual(<<"{}">>, encode(#{})).