%% The MIT License %% Copyright (c) 2011 Alisdair Sullivan %% 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(jsx_encoder). -export([encoder/1]). -spec encoder(OptsList::jsx:opts()) -> jsx:encoder(). encoder(OptsList) -> fun(Forms) -> start(Forms, [], [], jsx_utils:parse_opts(OptsList)) end. -include("../include/jsx_opts.hrl"). -ifndef(error). -define(error(Args), erlang:error(badarg, Args) ). -endif. -ifndef(incomplete). -define(incomplete(State, T, Stack, Opts), {incomplete, fun(Stream) when is_list(Stream) -> State(Stream, T, Stack, Opts) end } ). -endif. -ifndef(event). -define(event(Event, State, Rest, T, Stack, Opts), State(Rest, Event ++ T, Stack, Opts) ). -endif. start({string, String}, [], [], Opts) when is_binary(String); is_list(String) -> {ok, [{string, unicode:characters_to_list(jsx_utils:json_escape(String, Opts))}, end_json ] }; start({float, Float}, [], [], _Opts) when is_float(Float) -> {ok, [{float, Float}, end_json] }; start({integer, Int}, [], [], _Opts) when is_integer(Int) -> {ok, [{integer, Int}, end_json] }; start({literal, Atom}, [], [], _Opts) when Atom == true; Atom == false; Atom == null -> {ok, [{literal, Atom}, end_json] }; %% third parameter is a stack to match end_foos to start_foos start(Forms, [], [], Opts) when is_list(Forms) -> list_or_object(Forms, [], [], Opts); start(Raw, [], [], Opts) -> start(term_to_event(Raw), [], [], Opts). list_or_object([start_object|Forms], T, Stack, Opts) -> ?event([start_object], key, Forms, T, [object] ++ Stack, Opts); list_or_object([start_array|Forms], T, Stack, Opts) -> ?event([start_array], value, Forms, T, [array] ++ Stack, Opts); list_or_object([], T, Stack, Opts) -> ?incomplete(list_or_object, T, Stack, Opts); list_or_object(Forms, T, Stack, Opts) -> ?error([Forms, T, Stack, Opts]). key([{key, Key}|Forms], T, Stack, Opts) when is_binary(Key); is_list(Key) -> ?event([{key, unicode:characters_to_list(jsx_utils:json_escape(Key, Opts)) }], value, Forms, T, Stack, Opts ); key([end_object|Forms], T, [object|Stack], Opts) -> ?event([end_object], maybe_done, Forms, T, Stack, Opts); key([], T, Stack, Opts) -> ?incomplete(key, T, Stack, Opts); key(Forms, T, Stack, Opts) -> ?error([Forms, T, Stack, Opts]). value([{string, S}|Forms], T, Stack, Opts) when is_binary(S); is_list(S) -> ?event([{string, unicode:characters_to_list(jsx_utils:json_escape(S, Opts))}], maybe_done, Forms, T, Stack, Opts ); value([{float, F}|Forms], T, Stack, Opts) when is_float(F) -> ?event([{float, F}], maybe_done, Forms, T, Stack, Opts); value([{integer, I}|Forms], T, Stack, Opts) when is_integer(I) -> ?event([{integer, I}], maybe_done, Forms, T, Stack, Opts); value([{literal, L}|Forms], T, Stack, Opts) when L == true; L == false; L == null -> ?event([{literal, L}], maybe_done, Forms, T, Stack, Opts); value([start_object|Forms], T, Stack, Opts) -> ?event([start_object], key, Forms, T, [object] ++ Stack, Opts); value([start_array|Forms], T, Stack, Opts) -> ?event([start_array], maybe_done, Forms, T, [array] ++ Stack, Opts); value([end_array|Forms], T, [array|Stack], Opts) -> ?event([end_array], maybe_done, Forms, T, Stack, Opts); value([], T, Stack, Opts) -> ?incomplete(value, T, Stack, Opts); value(Forms, T, Stack, Opts) -> ?error([Forms, T, Stack, Opts]). maybe_done([end_json], T, [], Opts) -> ?event([end_json], done, [], T, [], Opts); maybe_done([end_object|Forms], T, [object|Stack], Opts) -> ?event([end_object], maybe_done, Forms, T, Stack, Opts); maybe_done([end_array|Forms], T, [array|Stack], Opts) -> ?event([end_array], maybe_done, Forms, T, Stack, Opts); maybe_done(Forms, T, [object|_] = Stack, Opts) -> key(Forms, T, Stack, Opts); maybe_done(Forms, T, [array|_] = Stack, Opts) -> value(Forms, T, Stack, Opts); maybe_done([], T, Stack, Opts) -> ?incomplete(maybe_done, T, Stack, Opts); maybe_done(Forms, T, Stack, Opts) -> ?error([Forms, T, Stack, Opts]). done([], T, [], _Opts) -> {ok, lists:reverse(T)}; done(Forms, T, Stack, Opts) -> ?error([Forms, T, Stack, Opts]). term_to_event(X) when is_integer(X) -> {integer, X}; term_to_event(X) when is_float(X) -> {float, X}; term_to_event(String) when is_binary(String) -> {string, String}; term_to_event(true) -> {literal, true}; term_to_event(false) -> {literal, false}; term_to_event(null) -> {literal, null}. -ifdef(TEST). -include_lib("eunit/include/eunit.hrl"). encode(Terms) -> try case (jsx:encoder([]))(Terms) of {ok, Terms} -> true %% matches [foo, end_json], aka naked terms ; {ok, [Terms, end_json]} -> true end catch error:badarg -> false end. encode_test_() -> [ {"empty object", ?_assert(encode([start_object, end_object, end_json]))}, {"empty array", ?_assert(encode([start_array, end_array, end_json]))}, {"nested empty objects", ?_assert(encode([start_object, {key, "empty object"}, start_object, {key, "empty object"}, start_object, end_object, end_object, end_object, end_json ]))}, {"nested empty arrays", ?_assert(encode([start_array, start_array, start_array, end_array, end_array, end_array, end_json ]))}, {"simple object", ?_assert(encode([start_object, {key, "a"}, {string, "hello"}, {key, "b"}, {integer, 1}, {key, "c"}, {float, 1.0}, {key, "d"}, {literal, true}, end_object, end_json ]))}, {"simple array", ?_assert(encode([start_array, {string, "hello"}, {integer, 1}, {float, 1.0}, {literal, true}, end_array, end_json ]))}, {"unbalanced array", ?_assertNot(encode([start_array, end_array, blerg, end_array, end_json ]))}, {"naked string", ?_assert(encode({string, "hello"}))}, {"naked literal", ?_assert(encode({literal, true}))}, {"naked integer", ?_assert(encode({integer, 1}))}, {"naked float", ?_assert(encode({float, 1.0}))} ]. -endif.