%%% @doc JSON decoding module %%% @private %%% @end %%% %%% Copyright (c) 2013-2014, Takeru Ohta <phjgt308@gmail.com> %%% %%% The MIT License %%% %%% Permission is hereby granted, free of charge, to any person obtaining a copy %%% of this software and associated documentation files (the "Software"), to deal %%% in the Software without restriction, including without limitation the rights %%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell %%% copies of the Software, and to permit persons to whom the Software is %%% furnished to do so, subject to the following conditions: %%% %%% The above copyright notice and this permission notice shall be included in %%% all copies or substantial portions of the Software. %%% %%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR %%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, %%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE %%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER %%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, %%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN %%% THE SOFTWARE. %%% %%%--------------------------------------------------------------------------------------- -module(jsone_decode). %%-------------------------------------------------------------------------------- %% Exported API %%-------------------------------------------------------------------------------- -export([decode/1]). %%-------------------------------------------------------------------------------- %% Macros & Types %%-------------------------------------------------------------------------------- -define(ERROR(Json), error({invalid_json, Json})). -type next() :: {array_next, [jsone:json_value()]} | {object_value, jsone:json_object_members()} | {object_next, jsone:json_string(), jsone:json_object_members()}. -type whitespace_next() :: value | array | object | string | {array_next, [jsone:json_value()]} | {object_value, jsone:json_string(), jsone:json_object_members()} | {object_next, jsone:json_string(), jsone:json_value(), jsone:json_object_members()}. %%-------------------------------------------------------------------------------- %% Exported Functions %%-------------------------------------------------------------------------------- %% @doc JSONバイナリをデコードする. %% %% デコードに失敗した場合は`{invalid_json, 失敗位置より後のJSON::binary()}'形式のエラーが送出される. -spec decode(binary()) -> {jsone:json_value(), RestJson::binary()}. decode(<<Json/binary>>) -> whitespace(Json, value, [], <<"">>). %%-------------------------------------------------------------------------------- %% Internal Functions %%-------------------------------------------------------------------------------- -spec next(binary(), jsone:json_value(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. next(<<Bin/binary>>, Value, [], _Buf) -> {Value, Bin}; next(<<Bin/binary>>, Value, [Next | Nexts], Buf) -> case Next of {array_next, Values} -> whitespace(Bin, {array_next, [Value | Values]}, Nexts, Buf); {object_value, Members} -> whitespace(Bin, {object_value, Value, Members}, Nexts, Buf); {object_next, Key, Members} -> whitespace(Bin, {object_next, Key, Value, Members}, Nexts, Buf) end. -spec whitespace(binary(), whitespace_next(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. whitespace(<<$ , Bin/binary>>, Next, Nexts, Buf) -> whitespace(Bin, Next, Nexts, Buf); whitespace(<<$\t, Bin/binary>>, Next, Nexts, Buf) -> whitespace(Bin, Next, Nexts, Buf); whitespace(<<$\r, Bin/binary>>, Next, Nexts, Buf) -> whitespace(Bin, Next, Nexts, Buf); whitespace(<<$\n, Bin/binary>>, Next, Nexts, Buf) -> whitespace(Bin, Next, Nexts, Buf); whitespace(<<Bin/binary>>, Next, Nexts, Buf) -> case Next of value -> value(Bin, Nexts, Buf); array -> array(Bin, Nexts, Buf); object -> object(Bin, Nexts, Buf); string -> case Bin of <<$", Bin2/binary>> -> string(Bin2, byte_size(Buf), Nexts, Buf); _ -> ?ERROR(Bin) end; {array_next, Values} -> array_next(Bin, Values, Nexts, Buf); {object_value, Key, Members} -> object_value(Bin, Key, Members, Nexts, Buf); {object_next, Key, Value, Members} -> object_next(Bin, [{Key, Value} | Members], Nexts, Buf) end. -spec value(binary(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. value(<<"false", Bin/binary>>, Nexts, Buf) -> next(Bin, false, Nexts, Buf); value(<<"true", Bin/binary>>, Nexts, Buf) -> next(Bin, true, Nexts, Buf); value(<<"null", Bin/binary>>, Nexts, Buf) -> next(Bin, null, Nexts, Buf); value(<<$[, Bin/binary>>, Nexts, Buf) -> whitespace(Bin, array, Nexts, Buf); value(<<${, Bin/binary>>, Nexts, Buf) -> whitespace(Bin, object, Nexts, Buf); value(<<$", Bin/binary>>, Nexts, Buf) -> string(Bin, byte_size(Buf), Nexts, Buf); value(<<Bin/binary>>, Nexts, Buf) -> number(Bin, Nexts, Buf). -spec array(binary(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. array(<<$], Bin/binary>>, Nexts, Buf) -> next(Bin, [], Nexts, Buf); array(<<Bin/binary>>, Nexts, Buf) -> whitespace(Bin, value, [{array_next, []} | Nexts], Buf). -spec array_next(binary(), [jsone:json_value()], [next()], binary()) -> {jsone:json_value(), Rest::binary()}. array_next(<<$], Bin/binary>>, Values, Nexts, Buf) -> next(Bin, lists:reverse(Values), Nexts, Buf); array_next(<<$,, Bin/binary>>, Values, Nexts, Buf) -> whitespace(Bin, value, [{array_next, Values} | Nexts], Buf); array_next(<<Bin/binary>>, _Values, _Nexts, _Buf) -> ?ERROR(Bin). -spec object(binary(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. object(<<$}, Bin/binary>>, Nexts, Buf) -> next(Bin, {object, []}, Nexts, Buf); object(<<Bin/binary>>, Nexts, Buf) -> whitespace(Bin, string, [{object_value, []} | Nexts], Buf). -spec object_value(binary(), jsone:json_string(), jsone:json_object_members(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. object_value(<<$:, Bin/binary>>, Key, Members, Nexts, Buf) -> whitespace(Bin, value, [{object_next, Key, Members} | Nexts], Buf); object_value(<<Bin/binary>>, _Key, _Members, _Nexts, _Buf) -> ?ERROR(Bin). -spec object_next(binary(), jsone:json_object_members(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. object_next(<<$}, Bin/binary>>, Members, Nexts, Buf) -> next(Bin, {object, Members}, Nexts, Buf); object_next(<<$,, Bin/binary>>, Members, Nexts, Buf) -> whitespace(Bin, string, [{object_value, Members} | Nexts], Buf); object_next(<<Bin/binary>>, _Members, _Nexts, _Buf) -> ?ERROR(Bin). -spec string(binary(), non_neg_integer(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. string(<<$", Bin/binary>>, Start, Nexts, Buf) -> next(Bin, binary:part(Buf, Start, byte_size(Buf) - Start), Nexts, Buf); string(<<$\\, B/binary>>, Start, Nexts, Buf) -> case B of <<$", Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $">>); <<$/, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $/>>); <<$\\,Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\\>>); <<$b, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\b>>); <<$f, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\f>>); <<$n, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\n>>); <<$r, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\r>>); <<$t, Bin/binary>> -> string(Bin, Start, Nexts, <<Buf/binary, $\t>>); <<$u, Bin/binary>> -> unicode_string(Bin, Start, Nexts, Buf); _ -> ?ERROR(B) end; string(<<C, Bin/binary>>, Start, Nexts, Buf) when 16#20 =< C -> string(Bin, Start, Nexts, <<Buf/binary, C>>). -spec unicode_string(binary(), non_neg_integer(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. unicode_string(<<N:4/binary, Bin/binary>>, Start, Nexts, Buf) -> case binary_to_integer(N, 16) of High when 16#D800 =< High, High =< 16#DBFF -> %% サロゲートペア case Bin of <<$\\, $u, N2:4/binary, Bin2/binary>> -> case binary_to_integer(N2, 16) of Low when 16#DC00 =< Low, Low =< 16#DFFF -> Unicode = 16#10000 + (High - 16#D800) * 16#400 + (Low - 16#DC00), string(Bin2, Start, Nexts, unicode_to_utf8(Unicode, Buf)); _ -> ?ERROR(Bin) end; _ -> ?ERROR(Bin) end; Unicode when 16#DC00 =< Unicode, Unicode =< 16#DFFF -> % サロゲートペアの後半部分 ?ERROR(<<N/binary, Bin/binary>>); Unicode -> string(Bin, Start, Nexts, unicode_to_utf8(Unicode, Buf)) end; unicode_string(<<Bin/binary>>, _Acc, _Nexts, _Buf) -> ?ERROR(Bin). -spec unicode_to_utf8(0..1114111, binary()) -> binary(). unicode_to_utf8(Code, Buf) when Code < 16#80 -> <<Buf/binary, Code>>; unicode_to_utf8(Code, Buf) when Code < 16#800 -> A = 2#11000000 bor (Code bsr 6), B = 2#10000000 bor (Code band 2#111111), <<Buf/binary, A, B>>; unicode_to_utf8(Code, Buf) when Code < 16#10000 -> A = 2#11100000 bor (Code bsr 12), B = 2#10000000 bor ((Code bsr 6) band 2#111111), C = 2#10000000 bor (Code band 2#111111), <<Buf/binary, A, B, C>>; unicode_to_utf8(Code, Buf) -> % NOTE: サロゲートペアの仕組み上、コード値が上限を越えることはないので、ここでの範囲チェックは不要 A = 2#11110000 bor (Code bsr 18), B = 2#10000000 bor ((Code bsr 12) band 2#111111), C = 2#10000000 bor ((Code bsr 6) band 2#111111), D = 2#10000000 bor (Code band 2#111111), <<Buf/binary, A, B, C, D>>. -spec number(binary(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number(<<$-, Bin/binary>>, Nexts, Buf) -> number_integer_part(Bin, -1, Nexts, Buf); number(<<Bin/binary>>, Nexts, Buf) -> number_integer_part(Bin, 1, Nexts, Buf). -spec number_integer_part(binary(), 1|-1, [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_integer_part(<<$0, Bin/binary>>, Sign, Nexts, Buf) -> number_fraction_part(Bin, Sign, 0, Nexts, Buf); number_integer_part(<<C, Bin/binary>>, Sign, Nexts, Buf) when $1 =< C, C =< $9 -> number_integer_part_rest(Bin, C - $0, Sign, Nexts, Buf); number_integer_part(<<Bin/binary>>, _Sign, _Nexts, _Buf) -> ?ERROR(Bin). -spec number_integer_part_rest(binary(), non_neg_integer(), 1|-1, [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_integer_part_rest(<<C, Bin/binary>>, N, Sign, Nexts, Buf) when $0 =< C, C =< $9 -> number_integer_part_rest(Bin, N * 10 + C - $0, Sign, Nexts, Buf); number_integer_part_rest(<<Bin/binary>>, N, Sign, Nexts, Buf) -> number_fraction_part(Bin, Sign, N, Nexts, Buf). -spec number_fraction_part(binary(), 1|-1, non_neg_integer(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_fraction_part(<<$., Bin/binary>>, Sign, Int, Nexts, Buf) -> number_fraction_part_rest(Bin, Sign, Int, 0, Nexts, Buf); number_fraction_part(<<Bin/binary>>, Sign, Int, Nexts, Buf) -> number_exponation_part(Bin, Sign * Int, 0, Nexts, Buf). -spec number_fraction_part_rest(binary(), 1|-1, non_neg_integer(), non_neg_integer(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_fraction_part_rest(<<C, Bin/binary>>, Sign, N, DecimalOffset, Nexts, Buf) when $0 =< C, C =< $9 -> number_fraction_part_rest(Bin, Sign, N * 10 + C - $0, DecimalOffset + 1, Nexts, Buf); number_fraction_part_rest(<<Bin/binary>>, Sign, N, DecimalOffset, Nexts, Buf) when DecimalOffset > 0 -> number_exponation_part(Bin, Sign * N, DecimalOffset, Nexts, Buf); number_fraction_part_rest(<<Bin/binary>>, _Sign, _N, _DecimalOffset, _Nexts, _Buf) -> ?ERROR(Bin). -spec number_exponation_part(binary(), integer(), non_neg_integer(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_exponation_part(<<$e, $+, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, 1, 0, true, Nexts, Buf); number_exponation_part(<<$E, $+, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, 1, 0, true, Nexts, Buf); number_exponation_part(<<$e, $-, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, -1, 0, true, Nexts, Buf); number_exponation_part(<<$E, $-, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, -1, 0, true, Nexts, Buf); number_exponation_part(<<$e, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, 1, 0, true, Nexts, Buf); number_exponation_part(<<$E, Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> number_exponation_part(Bin, N, DecimalOffset, 1, 0, true, Nexts, Buf); number_exponation_part(<<Bin/binary>>, N, DecimalOffset, Nexts, Buf) -> case DecimalOffset of 0 -> next(Bin, N, Nexts, Buf); _ -> next(Bin, N / math:pow(10, DecimalOffset), Nexts, Buf) end. -spec number_exponation_part(binary(), integer(), non_neg_integer(), 1|-1, non_neg_integer(), boolean(), [next()], binary()) -> {jsone:json_value(), Rest::binary()}. number_exponation_part(<<C, Bin/binary>>, N, DecimalOffset, ExpSign, Exp, _, Nexts, Buf) when $0 =< C, C =< $9 -> number_exponation_part(Bin, N, DecimalOffset, ExpSign, Exp * 10 + C - $0, false, Nexts, Buf); number_exponation_part(<<Bin/binary>>, N, DecimalOffset, ExpSign, Exp, false, Nexts, Buf) -> Pos = ExpSign * Exp - DecimalOffset, next(Bin, N * math:pow(10, Pos), Nexts, Buf); number_exponation_part(<<Bin/binary>>, _N, _DecimalOffset, _ExpSign, _Exp, _IsFirst, _Nexts, _Buf) -> ?ERROR(Bin).