add JSON decoding module

src/jsone_decode.erl

@@ -1,7 +1,7 @@
 -module(jsone_decode).
 
--compile(inline).
 -compile(native).
+-compile(bin_opt_info).
 
 -export([
          decode/2
@@ -58,58 +58,53 @@ object_next(<<$}, Bin/binary>>, Entries, Nexts) -> next(Bin, {object, lists:reve
 object_next(<<$,, Bin/binary>>, Entries, Nexts) -> whitespace(Bin, string, [{object_value, Entries} | Nexts]).
 
 string(<<$", Bin/binary>>,      Acc, Nexts) -> next(Bin, list_to_binary(lists:reverse(Acc)), Nexts);
-string(<<$\\, $", Bin/binary>>, Acc, Nexts) -> string(Bin, [$" | Acc], Nexts);
-string(<<$\\, $/, Bin/binary>>, Acc, Nexts) -> string(Bin, [$/ | Acc], Nexts);
-string(<<$\\, $\\,Bin/binary>>, Acc, Nexts) -> string(Bin, [$\\| Acc], Nexts);
-string(<<$\\, $b, Bin/binary>>, Acc, Nexts) -> string(Bin, [$\b | Acc], Nexts);
-string(<<$\\, $f, Bin/binary>>, Acc, Nexts) -> string(Bin, [$\f | Acc], Nexts);
-string(<<$\\, $n, Bin/binary>>, Acc, Nexts) -> string(Bin, [$\n | Acc], Nexts);
-string(<<$\\, $r, Bin/binary>>, Acc, Nexts) -> string(Bin, [$\r | Acc], Nexts);
-string(<<$\\, $t, Bin/binary>>, Acc, Nexts) -> string(Bin, [$\t | Acc], Nexts);
-string(<<$\\, $u, N:4/binary, Bin/binary>>, Acc, Nexts) ->
-    case binary_to_integer(N, 16) of
-        High when 16#D800 =< High, High =< 16#DBFF ->
-            <<$\\, $u, N2:4/binary, Bin2/binary>> = Bin,
-            case binary_to_integer(N2, 16) of
-                Low when 16#DC00 =< Low, Low =< 16#DFFF ->
-                    Unicode = 16#10000 + (High - 16#D800) * 16#400 + (Low - 16#DC00),
-                    string(Bin2, [unicode_to_utf8(Unicode) | Acc], Nexts)
-            end;
-        Unicode ->
-            string(Bin, [unicode_to_utf8(Unicode) | Acc], Nexts)
+string(<<$\\, B/binary>>, Acc, Nexts) ->
+    case B of
+        <<$", Bin/binary>> -> string(Bin, [$" | Acc], Nexts);
+        <<$/, Bin/binary>> -> string(Bin, [$/ | Acc], Nexts);
+        <<$\\,Bin/binary>> -> string(Bin, [$\\| Acc], Nexts);
+        <<$b, Bin/binary>> -> string(Bin, [$\b | Acc], Nexts);
+        <<$f, Bin/binary>> -> string(Bin, [$\f | Acc], Nexts);
+        <<$n, Bin/binary>> -> string(Bin, [$\n | Acc], Nexts);
+        <<$r, Bin/binary>> -> string(Bin, [$\r | Acc], Nexts);
+        <<$t, Bin/binary>> -> string(Bin, [$\t | Acc], Nexts);
+        <<$u, Bin/binary>> -> unicode_string(Bin, Acc, Nexts)
     end;
-string(<<C, Rest/binary>>, Acc, Nexts) when 16#20 =< C, C =< 16#21;
-                                            16#23 =< C, C =< 16#5B;
-                                            16#5D =< C, C =< 16#FF ->
-    ordinal_string_end(Rest, 0, [C | Acc], Nexts).
-
-%% XXX: name
-ordinal_string_end(<<C, Bin/binary>>, Pos, Acc, Nexts) when 16#20 =< C, C =< 16#21;
-                                                            16#23 =< C, C =< 16#5B;
-                                                            16#5D =< C, C =< 16#FF ->
-    ordinal_string_end(Bin, Pos + 1, [C | Acc], Nexts); %XXX:
-ordinal_string_end(<<Bin/binary>>, _Pos, Acc, Nexts) ->
-%    io:format("! ~p, ~p, ~p, ~p\n", [Bin, Pos, Acc, Nexts]),
-%    <<Bin1:Pos/binary, Bin2/binary>> = Bin,
-%    string(Bin2, [Bin1 | Acc], Nexts).
-    string(Bin, Acc, Nexts).
-
-unicode_to_utf8(Code) when Code < 16#80 ->
-    Code;
-unicode_to_utf8(Code) when Code < 16#800 ->
-    [2#11000000 + (Code bsr 6),
-     2#10000000 + (Code band 2#111111)];
-unicode_to_utf8(Code) when Code < 16#10000 ->
+string(<<C, Bin/binary>>, Acc, Nexts) when 16#20 =< C ->
+    string(Bin, [C | Acc], Nexts).
+
+unicode_string(<<N:4/binary, $\\, $u, N2:4/binary, Bin/binary>>, Acc, Nexts) ->
+    case {binary_to_integer(N, 16), binary_to_integer(N2, 16)} of
+        {High, Low} when 16#D800 =< High, High =< 16#DBFF,
+                         16#DC00 =< Low, Low =< 16#DFFF ->
+            Unicode = 16#10000 + (High - 16#D800) * 16#400 + (Low - 16#DC00),
+            string(Bin, unicode_to_utf8(Unicode, Acc), Nexts);
+        {A, B} ->
+            string(Bin, unicode_to_utf8(B, unicode_to_utf8(A, Acc)), Nexts)
+    end;
+unicode_string(<<N:4/binary, Bin/binary>>, Acc, Nexts) ->
+    Unicode = binary_to_integer(N, 16),
+    string(Bin, unicode_to_utf8(Unicode, Acc), Nexts).
+
+unicode_to_utf8(Code, Acc) when Code < 16#80 ->
+    [Code | Acc];
+unicode_to_utf8(Code, Acc) when Code < 16#800 ->
+    A = 2#11000000 bor (Code bsr 6),
+    B = 2#10000000 bor (Code band 2#111111),
+    [B, A | Acc];
+unicode_to_utf8(Code, Acc) when Code < 16#10000 ->
     %% NOTE: Codeの値が 16#D800 から 16#DFFF の範囲内にないことは、呼び出し元が保証している
-    [2#11100000 + (Code bsr 12),
-     2#10000000 + ((Code bsr 6) band 2#111111),
-     2#10000000 + (Code band 2#111111)];
-unicode_to_utf8(Code) ->
+    A = 2#11100000 bor (Code bsr 12),
+    B = 2#10000000 bor ((Code bsr 6) band 2#111111),
+    C = 2#10000000 bor (Code band 2#111111),
+    [C, B, A | Acc];
+unicode_to_utf8(Code, Acc) ->
     %% NOTE: ユニコード範囲内云々
-    [2#1111000 + (Code bsr 18),
-     2#1000000 + ((Code bsr 12) band 2#111111),
-     2#1000000 + ((Code bsr 12) band 2#111111),
-     2#1000000 + (Code band 2#111111)].
+    A = 2#11110000 bor (Code bsr 18),
+    B = 2#10000000 bor ((Code bsr 12) band 2#111111),
+    C = 2#10000000 bor ((Code bsr  6) band 2#111111),
+    D = 2#10000000 bor (Code band 2#111111),
+    [D, C, B, A | Acc].
 
 number(<<Bin/binary>>, Nexts) ->
     %% XXX:
@@ -120,3 +115,49 @@ number(<<C, Bin/binary>>, N, Nexts) when $0 =< C, C =< $9 ->
 number(<<Bin/binary>>, N, Nexts) -> next(Bin, N, Nexts).
 
 
+%% decode_number(<<$-, Bin/binary>>) -> {Num, Bin2} = decode_number_impl(Bin),
+%%                                      {-Num, Bin2};
+%% decode_number(<<$ , Bin/binary>>) -> decode_number(Bin);
+%% decode_number(<<$\t,Bin/binary>>) -> decode_number(Bin);
+%% decode_number(<<$\r,Bin/binary>>) -> decode_number(Bin);
+%% decode_number(<<$\n,Bin/binary>>) -> decode_number(Bin);
+%% decode_number(<<Bin/binary>>)     -> decode_number_impl(Bin).
+
+%% decode_number_impl(<<$0, Bin/binary>>) -> decode_fraction(Bin, 0);
+%% decode_number_impl(<<C, Bin/binary>>) when $1 =< C, C =< $9 -> decode_int(Bin, C - $0).
+
+%% decode_int(<<C, Bin/binary>>, Acc) when $0 =< C, C =< $9 ->
+%%     decode_int(Bin, (Acc*10) + (C-$0));
+%% decode_int(<<Bin/binary>>, Acc) ->
+%%     decode_fraction(Bin, Acc).
+
+%% decode_fraction(<<$., Bin/binary>>, Acc) ->
+%%     {Digit, Bin2} = decode_digit(Bin),
+%%     Frac  = Digit / (math:pow(10, byte_size(Bin) - byte_size(Bin2))),
+%%     decode_exponation(Bin2, Acc + Frac);
+%% decode_fraction(<<Bin/binary>>, Acc) ->
+%%     {Acc, Bin}.
+
+%% decode_exponation(<<$e, $+, Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, plus);
+%% decode_exponation(<<$E, $+, Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, plus);
+%% decode_exponation(<<$e, $-, Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, minus);
+%% decode_exponation(<<$E, $-, Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, minus);
+%% decode_exponation(<<$e,     Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, plus);
+%% decode_exponation(<<$E,     Bin/binary>>, Acc) -> decode_exponation(Bin, Acc, plus);
+%% decode_exponation(<<Bin/binary>>, Acc)         -> {Acc, Bin}.
+
+%% decode_exponation(<<Bin/binary>>, Acc, Sign) ->
+%%     {Digit, Bin2} = decode_digit(Bin),
+%%     Num = case Sign of
+%%               plus  -> Acc * math:pow(10, Digit);
+%%               minus -> Acc / math:pow(10, Digit)
+%%           end,
+%%     {Num, Bin2}.
+
+%% decode_digit(<<C, Bin/binary>>) when $0 =< C, C =< $9 -> 
+%%     decode_digit(Bin, C - $0).
+
+%% decode_digit(<<C, Bin/binary>>, Acc) when $0 =< C, C =< $9 ->
+%%     decode_digit(Bin, (Acc*10) - (C-$0));
+%% decode_digit(<<Bin/binary>>, Acc) ->
+%%     {Acc, Bin}.