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jsx/include/jsx_decoder.hrl

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%% The MIT License
%% Copyright (c) 2010 Alisdair Sullivan <alisdairsullivan@yahoo.ca>
%% 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.
%% this is the implementation of the utf backends for the jsx decoder. it's
%% included by the various jsx_utfxx.erl frontends and all modifications to
%% this file should take that into account
-export([decoder/1]).
%% exported solely to facilitate stupid trick i shouldn't be using
-export([start/4,
maybe_done/4,
done/4,
object/4,
array/4,
value/4,
colon/4,
key/4,
string/5,
escape/5,
escaped_unicode/6,
low_surrogate/6,
low_surrogate_u/6,
low_surrogate/7,
negative/5,
zero/5,
integer/5,
initial_decimal/5,
decimal/5,
e/5,
ex/5,
exp/5,
tr/4,
tru/4,
true/4,
fa/4,
fal/4,
fals/4,
false/4,
nu/4,
nul/4,
null/4
]).
-spec decoder(Opts::#opts{}) -> jsx_decoder().
decoder(Opts) ->
fun(JSON) -> start(JSON, [], [], Opts) end.
%% whitespace
-define(space, 16#20).
-define(tab, 16#09).
-define(cr, 16#0D).
-define(newline, 16#0A).
%% object delimiters
-define(start_object, 16#7B).
-define(end_object, 16#7D).
%% array delimiters
-define(start_array, 16#5B).
-define(end_array, 16#5D).
%% kv seperator
-define(comma, 16#2C).
-define(quote, 16#22).
-define(colon, 16#3A).
%% string escape sequences
-define(escape, 16#5C).
-define(rsolidus, 16#5C).
-define(solidus, 16#2F).
-define(formfeed, 16#0C).
-define(backspace, 16#08).
-define(unicode, 16#75).
%% math
-define(zero, 16#30).
-define(decimalpoint, 16#2E).
-define(negative, 16#2D).
-define(positive, 16#2B).
%% some useful guards
-define(is_hex(Symbol),
(Symbol >= $a andalso Symbol =< $z); (Symbol >= $A andalso Symbol =< $Z);
(Symbol >= $0 andalso Symbol =< $9)
).
-define(is_nonzero(Symbol),
Symbol >= $1 andalso Symbol =< $9
).
-define(is_noncontrol(Symbol),
(Symbol >= ?space)
).
-define(is_whitespace(Symbol),
Symbol =:= ?space; Symbol =:= ?tab; Symbol =:= ?cr; Symbol =:= ?newline
).
%% utf8 is the default encoding
-define(utf8, true).
-ifdef(utf16).
-undef(utf8).
-define(encoding, utf16).
-define(utfx, utf16).
-define(partial_codepoint(Bin), byte_size(Bin) < 2).
-endif.
-ifdef(utf16le).
-undef(utf8).
-define(encoding, utf16le).
-define(utfx, utf16-little).
-define(partial_codepoint(Bin), byte_size(Bin) < 2).
-endif.
-ifdef(utf32).
-undef(utf8).
-define(encoding, utf32).
-define(utfx, utf32).
-define(partial_codepoint(Bin), byte_size(Bin) < 4).
-endif.
-ifdef(utf32le).
-undef(utf8).
-define(encoding, utf32le).
-define(utfx, utf32-little).
-define(partial_codepoint(Bin), byte_size(Bin) < 4).
-endif.
-ifdef(utf8).
-define(encoding, utf8).
-define(utfx, utf8).
-define(partial_codepoint(Bin), byte_size(Bin) < 1).
-endif.
%% when parsing strings, the naive detection of partial codepoints is
%% insufficient. this incredibly anal function should detect all badly formed
%% utf sequences
-ifdef(utf8).
partial_utf(<<>>) -> true;
partial_utf(<<X>>) when X >= 16#c2, X =< 16#df -> true;
partial_utf(<<X, Rest/binary>>) when X >= 16#e0, X =< 16#ef ->
case Rest of
<<>> -> true
; <<Y>> when Y >= 16#80, Y =< 16#bf -> true
; _ -> false
end;
partial_utf(<<X, Rest/binary>>) when X >= 16#f0, X =< 16#f4 ->
case Rest of
<<>> -> true
; <<Y>> when Y >= 16#80, Y =< 16#bf -> true
; <<Y, Z>> when Y >= 16#80, Y =< 16#bf, Z >= 16#80, Z =< 16#bf -> true
; _ -> false
end;
partial_utf(_) -> false.
-endif.
-ifdef(utf16).
partial_utf(<<>>) -> true;
partial_utf(<<_X>>) -> true;
partial_utf(<<X, _Y>>) when X >= 16#d8, X =< 16#df -> true;
partial_utf(<<X, _Y, Z>>) when X >= 16#d8, X =< 16#df, Z >= 16#dc, Z =< 16#df ->
true;
partial_utf(_) -> false.
-endif.
-ifdef(utf16le).
partial_utf(<<>>) -> true;
%% this case is not strictly true, there are single bytes that should be
%% rejected, but they're rare enough they can be ignored
partial_utf(<<_X>>) -> true;
partial_utf(<<_Y, X>>) when X >= 16#d8, X =< 16#df -> true;
partial_utf(<<_Y, X, _Z>>) when X >= 16#d8, X =< 16#df -> true;
partial_utf(_) -> false.
-endif.
-ifdef(utf32).
partial_utf(<<>>) -> true;
partial_utf(<<_>>) -> true;
partial_utf(<<_, _>>) -> true;
partial_utf(<<_, _, _>>) -> true;
partial_utf(_) -> false.
-endif.
-ifdef(utf32le).
partial_utf(<<>>) -> true;
partial_utf(<<_>>) -> true;
partial_utf(<<_, _>>) -> true;
partial_utf(<<_, _, _>>) -> true;
partial_utf(_) -> false.
-endif.
incomplete(State, Bin, T, Args) ->
case ?partial_codepoint(Bin) of
true ->
{jsx, incomplete, fun(Stream)
when is_binary(Stream) ->
erlang:apply(?MODULE,
State,
[<<Bin/binary, Stream/binary>>, T] ++ Args
)
; (Else) -> {error, {badjson, Else}}
end}
; false -> {error, {badjson, Bin}}
end.
-ifndef(emit).
%% takes a list of `events` to present to client code and formats them
%% appropriately
iterate_wrapper([], Next) -> Next();
iterate_wrapper([Event|Events], Next) ->
{jsx, Event, fun() ->
iterate_wrapper(Events, Next)
end}.
-define(emit(Event, State, Rest, T, Stack, Opts),
State(Rest, Event ++ T, Stack, Opts)
).
done(<<S/?utfx, Rest/binary>>, T, [], Opts) when ?is_whitespace(S) ->
done(Rest, T, [], Opts);
done(<<>>, T, [], Opts=#opts{iterate = true}) ->
iterate_wrapper(lists:reverse([end_json] ++ T), fun() ->
incomplete(done, <<>>, [], [[], Opts])
end);
done(<<>>, T, [], Opts) ->
{jsx, lists:reverse([end_json] ++ T), fun(end_stream) ->
done(<<>>, T, [], Opts)
; (Stream) ->
done(Stream, T, [], Opts)
end};
done(Bin, T, [], Opts) ->
incomplete(done, Bin, T, [[], Opts]).
-else.
-define(next(State, Rest, T, Stack, Opts),
State(Rest, T, Stack, Opts)
).
done(<<S/?utfx, Rest/binary>>, T, [], Opts) when ?is_whitespace(S) ->
done(Rest, T, Opts);
done(<<>>, T, [], Opts) ->
?emit([end_json], done, Rest, T, [], Opts);
done(Bin, T, [], Opts) ->
incomplete(done, Bin, T, [[], Opts]).
-endif.
start(<<?start_object/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_object], object, Rest, T, [key|Stack], Opts);
start(<<?start_array/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_array], array, Rest, T, [array|Stack], Opts);
start(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts) ->
string(Rest, T, Stack, Opts, []);
start(<<$t/?utfx, Rest/binary>>, T, Stack, Opts) ->
tr(Rest, T, Stack, Opts);
start(<<$f/?utfx, Rest/binary>>, T, Stack, Opts) ->
fa(Rest, T, Stack, Opts);
start(<<$n/?utfx, Rest/binary>>, T, Stack, Opts) ->
nu(Rest, T, Stack, Opts);
start(<<?negative/?utfx, Rest/binary>>, T, Stack, Opts) ->
negative(Rest, T, Stack, Opts, "-");
start(<<?zero/?utfx, Rest/binary>>, T, Stack, Opts) ->
zero(Rest, T, Stack, Opts, "0");
start(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_nonzero(S) ->
integer(Rest, T, Stack, Opts, [S]);
start(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
start(Rest, T, Stack, Opts);
start(Bin, T, Stack, Opts) ->
incomplete(start, Bin, T, [Stack, Opts]).
maybe_done(<<?end_object/?utfx, Rest/binary>>, T, [object|Stack], Opts) ->
?emit([end_object], maybe_done, Rest, T, Stack, Opts);
maybe_done(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts) ->
?emit([end_array], maybe_done, Rest, T, Stack, Opts);
maybe_done(<<?comma/?utfx, Rest/binary>>, T, [object|Stack], Opts) ->
key(Rest, T, [key|Stack], Opts);
maybe_done(<<?comma/?utfx, Rest/binary>>, T, [array|_] = Stack, Opts) ->
value(Rest, T, Stack, Opts);
maybe_done(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
maybe_done(Rest, T, Stack, Opts);
maybe_done(Rest, T, [], Opts) ->
done(Rest, T, [], Opts);
maybe_done(Bin, T, Stack, Opts) ->
incomplete(maybe_done, Bin, T, [Stack, Opts]).
object(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts) ->
string(Rest, T, Stack, Opts, []);
object(<<?end_object/?utfx, Rest/binary>>, T, [key|Stack], Opts) ->
?emit([end_object], maybe_done, Rest, T, Stack, Opts);
object(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
object(Rest, T, Stack, Opts);
object(Bin, T, Stack, Opts) ->
incomplete(object, Bin, T, [Stack, Opts]).
array(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts) ->
string(Rest, T, Stack, Opts, []);
array(<<$t/?utfx, Rest/binary>>, T, Stack, Opts) ->
tr(Rest, T, Stack, Opts);
array(<<$f/?utfx, Rest/binary>>, T, Stack, Opts) ->
fa(Rest, T, Stack, Opts);
array(<<$n/?utfx, Rest/binary>>, T, Stack, Opts) ->
nu(Rest, T, Stack, Opts);
array(<<?negative/?utfx, Rest/binary>>, T, Stack, Opts) ->
negative(Rest, T, Stack, Opts, "-");
array(<<?zero/?utfx, Rest/binary>>, T, Stack, Opts) ->
zero(Rest, T, Stack, Opts, "0");
array(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_nonzero(S) ->
integer(Rest, T, Stack, Opts, [S]);
array(<<?start_object/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_object], object, Rest, T, [key|Stack], Opts);
array(<<?start_array/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_array], array, Rest, T, [array|Stack], Opts);
array(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts) ->
maybe_done(Rest, [end_array] ++ T, Stack, Opts);
array(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
array(Rest, T, Stack, Opts);
array(Bin, T, Stack, Opts) ->
incomplete(array, Bin, T, [Stack, Opts]).
value(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts) ->
string(Rest, T, Stack, Opts, []);
value(<<$t/?utfx, Rest/binary>>, T, Stack, Opts) ->
tr(Rest, T, Stack, Opts);
value(<<$f/?utfx, Rest/binary>>, T, Stack, Opts) ->
fa(Rest, T, Stack, Opts);
value(<<$n/?utfx, Rest/binary>>, T, Stack, Opts) ->
nu(Rest, T, Stack, Opts);
value(<<?negative/?utfx, Rest/binary>>, T, Stack, Opts) ->
negative(Rest, T, Stack, Opts, "-");
value(<<?zero/?utfx, Rest/binary>>, T, Stack, Opts) ->
zero(Rest, T, Stack, Opts, "0");
value(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_nonzero(S) ->
integer(Rest, T, Stack, Opts, [S]);
value(<<?start_object/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_object], object, Rest, T, [key|Stack], Opts);
value(<<?start_array/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([start_array], array, Rest, T, [array|Stack], Opts);
value(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
value(Rest, T, Stack, Opts);
value(Bin, T, Stack, Opts) ->
incomplete(value, Bin, T, [Stack, Opts]).
colon(<<?colon/?utfx, Rest/binary>>, T, [key|Stack], Opts) ->
value(Rest, T, [object|Stack], Opts);
colon(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
colon(Rest, T, Stack, Opts);
colon(Bin, T, Stack, Opts) ->
incomplete(colon, Bin, T, [Stack, Opts]).
key(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts) ->
string(Rest, T, Stack, Opts, []);
key(<<S/?utfx, Rest/binary>>, T, Stack, Opts) when ?is_whitespace(S) ->
key(Rest, T, Stack, Opts);
key(Bin, T, Stack, Opts) ->
incomplete(key, Bin, T, [Stack, Opts]).
%% string has an additional parameter, an accumulator (Acc) used to hold the
%% intermediate representation of the string being parsed. using a list of
%% integers representing unicode codepoints is faster than constructing
%% binaries, there's a branch kicking around which proves it
%% string uses partial_utf/1 to cease parsing when invalid encodings are
%% encountered rather than just checking remaining binary size like other
%% states to eliminate certain incomplete states
string(<<?quote/?utfx, Rest/binary>>, T, [key|_] = Stack, Opts, Acc) ->
?emit([{key, lists:reverse(Acc)}], colon, Rest, T, Stack, Opts);
string(<<?quote/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
?emit([{string, lists:reverse(Acc)}], maybe_done, Rest, T, Stack, Opts);
string(<<?rsolidus/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
escape(Rest, T, Stack, Opts, Acc);
%% things get dumb here. erlang doesn't properly restrict unicode non-characters
%% so you can't trust the codepoints it returns always
%% the range 32..16#fdcf is safe, so allow that
string(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S), S < 16#fdd0 ->
string(Rest, T, Stack, Opts, [S] ++ Acc);
%% the range 16#fdf0..16#fffd is also safe
string(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc)
when S > 16#fdef, S < 16#fffe ->
string(Rest, T, Stack, Opts, [S] ++ Acc);
%% yes, i think it's insane too
string(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc)
when S > 16#ffff andalso
S =/= 16#1fffe andalso S =/= 16#1ffff andalso
S =/= 16#2fffe andalso S =/= 16#2ffff andalso
S =/= 16#3fffe andalso S =/= 16#3ffff andalso
S =/= 16#4fffe andalso S =/= 16#4ffff andalso
S =/= 16#5fffe andalso S =/= 16#5ffff andalso
S =/= 16#6fffe andalso S =/= 16#6ffff andalso
S =/= 16#7fffe andalso S =/= 16#7ffff andalso
S =/= 16#8fffe andalso S =/= 16#8ffff andalso
S =/= 16#9fffe andalso S =/= 16#9ffff andalso
S =/= 16#afffe andalso S =/= 16#affff andalso
S =/= 16#bfffe andalso S =/= 16#bffff andalso
S =/= 16#cfffe andalso S =/= 16#cffff andalso
S =/= 16#dfffe andalso S =/= 16#dffff andalso
S =/= 16#efffe andalso S =/= 16#effff andalso
S =/= 16#ffffe andalso S =/= 16#fffff andalso
S =/= 16#10fffe andalso S =/= 16#10ffff ->
string(Rest, T, Stack, Opts, [S] ++ Acc);
string(Bin, T, Stack, Opts, Acc) ->
case partial_utf(Bin) of
true ->
{jsx, incomplete, fun(Stream)
when is_binary(Stream) ->
string(<<Bin/binary, Stream/binary>>, T, Stack, Opts, Acc)
; (Else) ->
{error, {badjson, Else}}
end}
; false ->
case Opts#opts.loose_unicode of
true -> noncharacter(Bin, T, Stack, Opts, Acc)
; false -> {error, {badjson, Bin}}
end
end.
%% we don't need to guard against partial utf here, because it's already taken
%% care of in string. theoretically, the last clause of noncharacter/4 is
%% unreachable
-ifdef(utf8).
%% non-characters erlang doesn't recognize as non-characters, idiotically
noncharacter(<<S/utf8, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S) ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% u+fffe and u+ffff
noncharacter(<<239, 191, X, Rest/binary>>, T, Stack, Opts, Acc)
when X == 190; X == 191 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% surrogates
noncharacter(<<237, X, _, Rest/binary>>, T, Stack, Opts, Acc) when X >= 160 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
noncharacter(Bin, _T, _Stack, _Opts, _Acc) ->
{error, {badjson, Bin}}.
-endif.
-ifdef(utf16).
%% non-characters blah blah
noncharacter(<<S/utf16, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S) ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% u+ffff and u+fffe
noncharacter(<<255, X, Rest/binary>>, T, Stack, Opts, Acc)
when X == 254; X == 255 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% surrogates
noncharacter(<<X, _, Rest/binary>>, T, Stack, Opts, Acc)
when X >= 216, X =< 223 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
noncharacter(Bin, _T, _Stack, _Opts, _Acc) ->
{error, {badjson, Bin}}.
-endif.
-ifdef(utf16le).
%% non-characters blah blah
noncharacter(<<S/utf16-little, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S) ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% u+ffff and u+fffe
noncharacter(<<X, 255, Rest/binary>>, T, Stack, Opts, Acc)
when X == 254; X == 255 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% surrogates
noncharacter(<<_, X, Rest/binary>>, T, Stack, Opts, Acc)
when X >= 216, X =< 223 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
noncharacter(Bin, _T, _Stack, _Opts, _Acc) ->
{error, {badjson, Bin}}.
-endif.
-ifdef(utf32).
%% non-characters blah blah
noncharacter(<<S/utf32, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S) ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% u+ffff and u+fffe
noncharacter(<<0, 0, 255, X, Rest/binary>>, T, Stack, Opts, Acc)
when X == 254; X == 255 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% surrogates
noncharacter(<<0, 0, X, _, Rest/binary>>, T, Stack, Opts, Acc)
when X >= 216, X =< 223 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
noncharacter(Bin, _T, _Stack, _Opts, _Acc) ->
{error, {badjson, Bin}}.
-endif.
-ifdef(utf32le).
%% non-characters blah blah
noncharacter(<<S/utf32-little, Rest/binary>>, T, Stack, Opts, Acc)
when ?is_noncontrol(S) ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% u+ffff and u+fffe
noncharacter(<<X, 255, 0, 0, Rest/binary>>, T, Stack, Opts, Acc)
when X == 254; X == 255 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
%% surrogates
noncharacter(<<_, X, 0, 0, Rest/binary>>, T, Stack, Opts, Acc)
when X >= 216, X =< 223 ->
string(Rest, T, Stack, Opts, [16#fffd] ++ Acc);
noncharacter(Bin, _T, _Stack, _Opts, _Acc) ->
{error, {badjson, Bin}}.
-endif.
%% only thing to note here is the additional accumulator passed to
%% escaped_unicode used to hold the codepoint sequence. unescessary, but nicer
%% than using the string accumulator
escape(<<$b/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
string(Rest, T, Stack, Opts, "\b" ++ Acc);
escape(<<$f/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
string(Rest, T, Stack, Opts, "\f" ++ Acc);
escape(<<$n/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
string(Rest, T, Stack, Opts, "\n" ++ Acc);
escape(<<$r/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
string(Rest, T, Stack, Opts, "\r" ++ Acc);
escape(<<$t/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
string(Rest, T, Stack, Opts, "\t" ++ Acc);
escape(<<$u/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
escaped_unicode(Rest, T, Stack, Opts, Acc, []);
escape(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc)
when S =:= ?quote; S =:= ?solidus; S =:= ?rsolidus ->
string(Rest, T, Stack, Opts, [S] ++ Acc);
escape(Bin, T, Stack, Opts, Acc) ->
incomplete(escape, Bin, T, [Stack, Opts, Acc]).
%% this code is ugly and unfortunate, but so is json's handling of escaped
%% unicode codepoint sequences.
escaped_unicode(<<D/?utfx, Rest/binary>>, T, Stack, Opts, String, [C, B, A])
when ?is_hex(D) ->
case erlang:list_to_integer([A, B, C, D], 16) of
%% high surrogate, we need a low surrogate next
X when X >= 16#d800, X =< 16#dbff ->
low_surrogate(Rest, T, Stack, Opts, String, X)
%% non-characters, you're not allowed to exchange these
; X when X == 16#fffe; X == 16#ffff; X >= 16#fdd0, X =< 16#fdef ->
case Opts#opts.loose_unicode of
true ->
string(Rest, T, Stack, Opts, [16#fffd] ++ String)
; false ->
{error, {badjson, <<D/?utfx, Rest/binary>>}}
end
%% allowing interchange of null bytes allows attackers to forge
%% malicious streams
; X when X == 16#0000 ->
case Opts#opts.loose_unicode of
true ->
string(Rest, T, Stack, Opts, [16#fffd] ++ String)
; false ->
{error, {badjson, <<D/?utfx, Rest/binary>>}}
end
%% anything else
; X ->
string(Rest, T, Stack, Opts, [X] ++ String)
end;
escaped_unicode(<<S/?utfx, Rest/binary>>, T, Stack, Opts, String, Acc)
when ?is_hex(S) ->
escaped_unicode(Rest, T, Stack, Opts, String, [S] ++ Acc);
escaped_unicode(Bin, T, Stack, Opts, String, Acc) ->
incomplete(escaped_unicode, Bin, T, [Stack, Opts, String, Acc]).
low_surrogate(<<?rsolidus/?utfx, Rest/binary>>, T, Stack, Opts, String, High) ->
low_surrogate_u(Rest, T, Stack, Opts, String, High);
%% not an escaped codepoint, our high codepoint is illegal. dispatch back to
%% string to handle
low_surrogate(<<S/?utfx, Rest/binary>> = Bin, T, Stack, Opts, String, _) ->
case Opts#opts.loose_unicode of
true ->
string(Bin, T, Stack, Opts, [16#fffd] ++ String)
; false ->
{error, {badjson, <<S/?utfx, Rest/binary>>}}
end;
low_surrogate(Bin, T, Stack, Opts, String, High) ->
incomplete(low_surrogate, Bin, T, [Stack, Opts, String, High]).
low_surrogate_u(<<$u/?utfx, Rest/binary>>, T, Stack, Opts, String, H) ->
low_surrogate(Rest, T, Stack, Opts, String, [], H);
%% not a low surrogate, dispatch back to string to handle, including the
%% rsolidus we parsed previously
low_surrogate_u(<<S/?utfx, Rest/binary>> = Bin, T, Stack, Opts, String, _) ->
case Opts#opts.loose_unicode of
true ->
string(<<?rsolidus/?utfx, Bin/binary>>,
T,
Stack,
Opts,
[16#fffd] ++ String
)
; false ->
{error, {badjson, <<S/?utfx, Rest/binary>>}}
end;
low_surrogate_u(Bin, T, Stack, Opts, String, H) ->
incomplete(low_surrogate_u, Bin, T, [Stack, Opts, String, H]).
low_surrogate(<<D/?utfx, Rest/binary>>, T, Stack, Opts, String, [C, B, A], H)
when ?is_hex(D) ->
case erlang:list_to_integer([A, B, C, D], 16) of
X when X >= 16#dc00, X =< 16#dfff ->
V = surrogate_to_codepoint(H, X),
case V rem 16#10000 of Y when Y == 16#fffe; Y == 16#ffff ->
case Opts#opts.loose_unicode of
true ->
string(Rest, T, Stack, Opts, [16#fffd] ++ String)
; false ->
{error, {badjson, <<D/?utfx, Rest/binary>>}}
end
; _ ->
string(Rest, T, Stack, Opts, [V] ++ String)
end
%% not a low surrogate, bad bad bad
; _ ->
case Opts#opts.loose_unicode of
true ->
string(Rest, T, Stack, Opts, [16#fffd, 16#fffd] ++ String)
; false ->
{error, {badjson, <<D/?utfx, Rest/binary>>}}
end
end;
low_surrogate(<<S/?utfx, Rest/binary>>, T, Stack, Opts, String, Acc, H)
when ?is_hex(S) ->
low_surrogate(Rest, T, Stack, Opts, String, [S] ++ Acc, H);
low_surrogate(Bin, T, Stack, Opts, String, Acc, H) ->
incomplete(low_surrogate, Bin, T, [Stack, Opts, String, Acc, H]).
%% stole this from the unicode spec
surrogate_to_codepoint(High, Low) ->
(High - 16#d800) * 16#400 + (Low - 16#dc00) + 16#10000.
%% like strings, numbers are collected in an intermediate accumulator before
%% being emitted to the callback handler
negative(<<$0/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
zero(Rest, T, Stack, Opts, "0" ++ Acc);
negative(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_nonzero(S) ->
integer(Rest, T, Stack, Opts, [S] ++ Acc);
negative(Bin, T, Stack, Opts, Acc) ->
incomplete(negative, Bin, T, [Stack, Opts, Acc]).
zero(<<?end_object/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([end_object, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
zero(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts, Acc) ->
?emit([end_array, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
zero(<<?comma/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([format_number(Acc)], key, Rest, T, [key|Stack], Opts);
zero(<<?comma/?utfx, Rest/binary>>, T, [array|_] = Stack, Opts, Acc) ->
?emit([format_number(Acc)], value, Rest, T, Stack, Opts);
zero(<<?decimalpoint/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
initial_decimal(Rest, T, Stack, Opts, {Acc, []});
zero(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_whitespace(S) ->
?emit([format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
zero(<<>>, T, [], Opts, Acc) ->
{jsx, incomplete, fun(end_stream) ->
?emit([format_number(Acc)], done, <<>>, T, [], Opts)
; (Stream) when is_binary(Stream) ->
zero(Stream, T, [], Opts, Acc)
; (Else) -> {error, {badjson, Else}}
end};
zero(Bin, T, Stack, Opts, Acc) ->
incomplete(zero, Bin, T, [Stack, Opts, Acc]).
integer(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_nonzero(S) ->
integer(Rest, T, Stack, Opts, [S] ++ Acc);
integer(<<?end_object/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([end_object, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
integer(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts, Acc) ->
?emit([end_array, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
integer(<<?comma/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([format_number(Acc)], key, Rest, T, [key|Stack], Opts);
integer(<<?comma/?utfx, Rest/binary>>, T, [array|_] = Stack, Opts, Acc) ->
?emit([format_number(Acc)], value, Rest, T, Stack, Opts);
integer(<<?decimalpoint/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
initial_decimal(Rest, T, Stack, Opts, {Acc, []});
integer(<<?zero/?utfx, Rest/binary>>, T, Stack, Opts, Acc) ->
integer(Rest, T, Stack, Opts, [?zero] ++ Acc);
integer(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when S =:= $e; S =:= $E ->
e(Rest, T, Stack, Opts, {Acc, [], []});
integer(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_whitespace(S) ->
?emit([format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
integer(<<>>, T, [], Opts, Acc) ->
{jsx, incomplete, fun(end_stream) ->
?emit([format_number(Acc)], done, <<>>, T, [], Opts)
; (Stream) when is_binary(Stream) ->
integer(Stream, T, [], Opts, Acc)
; (Else) -> {error, {badjson, Else}}
end};
integer(Bin, T, Stack, Opts, Acc) ->
incomplete(integer, Bin, T, [Stack, Opts, Acc]).
initial_decimal(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac})
when S =:= ?zero; ?is_nonzero(S) ->
decimal(Rest, T, Stack, Opts, {Int, [S] ++ Frac});
initial_decimal(Bin, T, Stack, Opts, Acc) ->
incomplete(initial_decimal, Bin, T, [Stack, Opts, Acc]).
decimal(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac})
when S=:= ?zero; ?is_nonzero(S) ->
decimal(Rest, T, Stack, Opts, {Int, [S] ++ Frac});
decimal(<<?end_object/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([end_object, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
decimal(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts, Acc) ->
?emit([end_array, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
decimal(<<?comma/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([format_number(Acc)], key, Rest, T, [key|Stack], Opts);
decimal(<<?comma/?utfx, Rest/binary>>, T, [array|_] = Stack, Opts, Acc) ->
?emit([format_number(Acc)], value, Rest, T, Stack, Opts);
decimal(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac})
when S =:= $e; S =:= $E ->
e(Rest, T, Stack, Opts, {Int, Frac, []});
decimal(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_whitespace(S) ->
?emit([format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
decimal(<<>>, T, [], Opts, Acc) ->
{jsx, incomplete, fun(end_stream) ->
?emit([format_number(Acc)], done, <<>>, T, [], Opts)
; (Stream) when is_binary(Stream) ->
decimal(Stream, T, [], Opts, Acc)
; (Else) -> {error, {badjson, Else}}
end};
decimal(Bin, T, Stack, Opts, Acc) ->
incomplete(decimal, Bin, T, [Stack, Opts, Acc]).
e(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac, Exp})
when S =:= ?zero; ?is_nonzero(S) ->
exp(Rest, T, Stack, Opts, {Int, Frac, [S] ++ Exp});
e(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac, Exp})
when S =:= ?positive; S =:= ?negative ->
ex(Rest, T, Stack, Opts, {Int, Frac, [S] ++ Exp});
e(Bin, T, Stack, Opts, Acc) ->
incomplete(e, Bin, T, [Stack, Opts, Acc]).
ex(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac, Exp})
when S =:= ?zero; ?is_nonzero(S) ->
exp(Rest, T, Stack, Opts, {Int, Frac, [S] ++ Exp});
ex(Bin, T, Stack, Opts, Acc) ->
incomplete(ex, Bin, T, [Stack, Opts, Acc]).
exp(<<S/?utfx, Rest/binary>>, T, Stack, Opts, {Int, Frac, Exp})
when S =:= ?zero; ?is_nonzero(S) ->
exp(Rest, T, Stack, Opts, {Int, Frac, [S] ++ Exp});
exp(<<?end_object/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([end_object, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
exp(<<?end_array/?utfx, Rest/binary>>, T, [array|Stack], Opts, Acc) ->
?emit([end_array, format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
exp(<<?comma/?utfx, Rest/binary>>, T, [object|Stack], Opts, Acc) ->
?emit([format_number(Acc)], key, Rest, T, [key|Stack], Opts);
exp(<<?comma/?utfx, Rest/binary>>, T, [array|_] = Stack, Opts, Acc) ->
?emit([format_number(Acc)], value, Rest, T, Stack, Opts);
exp(<<S/?utfx, Rest/binary>>, T, Stack, Opts, Acc) when ?is_whitespace(S) ->
?emit([format_number(Acc)], maybe_done, Rest, T, Stack, Opts);
exp(<<>>, T, [], Opts, Acc) ->
{jsx, incomplete, fun(end_stream) ->
?emit([format_number(Acc)], done, <<>>, T, [], Opts)
; (Stream) when is_binary(Stream) ->
exp(Stream, T, [], Opts, Acc)
; (Else) -> {error, {badjson, Else}}
end};
exp(Bin, T, Stack, Opts, Acc) ->
incomplete(exp, Bin, T, [Stack, Opts, Acc]).
format_number(Int) when is_list(Int) ->
{integer, list_to_integer(lists:reverse(Int))};
format_number({Int, Frac}) ->
{float, list_to_float(lists:reverse(Frac ++ "." ++ Int))};
format_number({Int, [], Exp}) ->
{float, list_to_float(lists:reverse(Exp ++ "e0." ++ Int))};
format_number({Int, Frac, Exp}) ->
{float, list_to_float(lists:reverse(Exp ++ "e" ++ Frac ++ "." ++ Int))}.
tr(<<$r/?utfx, Rest/binary>>, T, Stack, Opts) ->
tru(Rest, T, Stack, Opts);
tr(Bin, T, Stack, Opts) ->
incomplete(tr, Bin, T, [Stack, Opts]).
tru(<<$u/?utfx, Rest/binary>>, T, Stack, Opts) ->
true(Rest, T, Stack, Opts);
tru(Bin, T, Stack, Opts) ->
incomplete(tru, Bin, T, [Stack, Opts]).
true(<<$e/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([{literal, true}], maybe_done, Rest, T, Stack, Opts);
true(Bin, T, Stack, Opts) ->
incomplete(true, Bin, T, [Stack, Opts]).
fa(<<$a/?utfx, Rest/binary>>, T, Stack, Opts) ->
fal(Rest, T, Stack, Opts);
fa(Bin, T, Stack, Opts) ->
incomplete(fa, Bin, T, [Stack, Opts]).
fal(<<$l/?utfx, Rest/binary>>, T, Stack, Opts) ->
fals(Rest, T, Stack, Opts);
fal(Bin, T, Stack, Opts) ->
incomplete(fal, Bin, T, [Stack, Opts]).
fals(<<$s/?utfx, Rest/binary>>, T, Stack, Opts) ->
false(Rest, T, Stack, Opts);
fals(Bin, T, Stack, Opts) ->
incomplete(fals, Bin, T, [Stack, Opts]).
false(<<$e/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([{literal, false}], maybe_done, Rest, T, Stack, Opts);
false(Bin, T, Stack, Opts) ->
incomplete(false, Bin, T, [Stack, Opts]).
nu(<<$u/?utfx, Rest/binary>>, T, Stack, Opts) ->
nul(Rest, T, Stack, Opts);
nu(Bin, T, Stack, Opts) ->
incomplete(nu, Bin, T, [Stack, Opts]).
nul(<<$l/?utfx, Rest/binary>>, T, Stack, Opts) ->
null(Rest, T, Stack, Opts);
nul(Bin, T, Stack, Opts) ->
incomplete(nul, Bin, T, [Stack, Opts]).
null(<<$l/?utfx, Rest/binary>>, T, Stack, Opts) ->
?emit([{literal, null}], maybe_done, Rest, T, Stack, Opts);
null(Bin, T, Stack, Opts) ->
incomplete(null, Bin, T, [Stack, Opts]).
-ifdef(TEST).
-include_lib("eunit/include/eunit.hrl").
noncharacters_test_() ->
[
{"noncharacters - badjson",
?_assertEqual(check_bad(noncharacters()), [])
},
{"noncharacters - replaced",
?_assertEqual(check_replaced(noncharacters()), [])
}
].
extended_noncharacters_test_() ->
[
{"extended noncharacters - badjson",
?_assertEqual(check_bad(extended_noncharacters()), [])
},
{"extended noncharacters - replaced",
?_assertEqual(check_replaced(extended_noncharacters()), [])
}
].
surrogates_test_() ->
[
{"surrogates - badjson",
?_assertEqual(check_bad(surrogates()), [])
},
{"surrogates - replaced",
?_assertEqual(check_replaced(surrogates()), [])
}
].
control_test_() ->
[
{"control characters - badjson",
?_assertEqual(check_bad(control_characters()), [])
}
].
reserved_test_() ->
[
{"reserved noncharacters - badjson",
?_assertEqual(check_bad(reserved_space()), [])
},
{"reserved noncharacters - replaced",
?_assertEqual(check_replaced(reserved_space()), [])
}
].
zero_test_() ->
[
{"nullbyte - badjson",
?_assertEqual(check_bad(zero()), [])
}
].
good_characters_test_() ->
[
{"acceptable codepoints",
?_assertEqual(check_good(good()), [])
},
{"acceptable extended",
?_assertEqual(check_good(good_extended()), [])
}
].
check_bad(List) ->
lists:dropwhile(fun({_, {error, badjson}}) -> true ; (_) -> false end,
check(List, [], [])
).
check_replaced(List) ->
lists:dropwhile(fun({_, [{string, [16#fffd]}|_]}) ->
true
; (_) ->
false
end,
check(List, [loose_unicode], [])
).
check_good(List) ->
lists:dropwhile(fun({_, [{string, _}]}) -> true ; (_) -> false end,
check(List, [], [])
).
check([], _Opts, Acc) -> Acc;
check([H|T], Opts, Acc) ->
R = decode(to_fake_utf(H, ?encoding), Opts),
check(T, Opts, [{H, R}] ++ Acc).
decode(JSON, Opts) ->
case (jsx:decoder(Opts))(JSON) of
{jsx, Events, _} -> loop(Events, [])
; {error, {badjson, _}} -> {error, badjson}
end.
loop([end_json], Acc) -> lists:reverse(Acc);
loop([Event|Events], Acc) -> loop(Events, [Event] ++ Acc);
loop(_, _) -> {error, badjson}.
noncharacters() -> lists:seq(16#fffe, 16#ffff).
extended_noncharacters() ->
[16#1fffe, 16#1ffff, 16#2fffe, 16#2ffff]
++ [16#3fffe, 16#3ffff, 16#4fffe, 16#4ffff]
++ [16#5fffe, 16#5ffff, 16#6fffe, 16#6ffff]
++ [16#7fffe, 16#7ffff, 16#8fffe, 16#8ffff]
++ [16#9fffe, 16#9ffff, 16#afffe, 16#affff]
++ [16#bfffe, 16#bffff, 16#cfffe, 16#cffff]
++ [16#dfffe, 16#dffff, 16#efffe, 16#effff]
++ [16#ffffe, 16#fffff, 16#10fffe, 16#10ffff].
surrogates() -> lists:seq(16#d800, 16#dfff).
control_characters() -> lists:seq(1, 31).
reserved_space() -> lists:seq(16#fdd0, 16#fdef).
zero() -> [0].
good() -> [32, 33]
++ lists:seq(16#23, 16#5b)
++ lists:seq(16#5d, 16#d7ff)
++ lists:seq(16#e000, 16#fdcf)
++ lists:seq(16#fdf0, 16#fffd).
good_extended() -> lists:seq(16#100000, 16#10fffd).
%% erlang refuses to encode certain codepoints, so fake them all
to_fake_utf(N, utf8) when N < 16#0080 -> <<34/utf8, N:8, 34/utf8>>;
to_fake_utf(N, utf8) when N < 16#0800 ->
<<0:5, Y:5, X:6>> = <<N:16>>,
<<34/utf8, 2#110:3, Y:5, 2#10:2, X:6, 34/utf8>>;
to_fake_utf(N, utf8) when N < 16#10000 ->
<<Z:4, Y:6, X:6>> = <<N:16>>,
<<34/utf8, 2#1110:4, Z:4, 2#10:2, Y:6, 2#10:2, X:6, 34/utf8>>;
to_fake_utf(N, utf8) ->
<<0:3, W:3, Z:6, Y:6, X:6>> = <<N:24>>,
<<34/utf8, 2#11110:5, W:3, 2#10:2, Z:6, 2#10:2, Y:6, 2#10:2, X:6, 34/utf8>>;
to_fake_utf(N, utf16) when N < 16#10000 -> <<34/utf16, N:16, 34/utf16>>;
to_fake_utf(N, utf16) -> <<34/utf16, N/utf16, 34/utf16>>;
to_fake_utf(N, utf16le) when N < 16#10000 ->
<<A:8, B:8>> = <<N:16>>,
<<34, 0, B:8, A:8, 34, 0>>;
to_fake_utf(N, utf16le) -> <<34/utf16-little, N/utf16-little, 34/utf16-little>>;
to_fake_utf(N, utf32) -> <<34/utf32, N:32, 34/utf32>>;
to_fake_utf(N, utf32le) ->
<<A:8, B:8, C:8, D:8>> = <<N:32>>,
<<34/utf32-little, D:8, C:8, B:8, A:8, 34/utf32-little>>.
-endif.
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