factor out gen_json

README.markdown

@@ -6,12 +6,12 @@ copyright 2011, 2012 alisdair sullivan
 
 jsx is released under the terms of the [MIT][MIT] license
 
-
-## quickstart ##
-
 to build jsx, `make` or `./rebar compile`
 
 
+## api ##
+
+
 **converting json to erlang terms**
 
 parses a JSON text (a utf8 encoded binary) and produces an erlang term (see json <-> erlang mapping details below)
@@ -173,77 +173,6 @@ json arrays are represented with erlang lists of json values as described in thi
 json objects are represented by erlang proplists. the empty object has the special representation `[{}]` to differentiate it from the empty list. ambiguities like `[true, false]` prevent using the shorthand form of property lists using atoms as properties. all properties must be tuples. all keys must be encoded as in `string`, above, or as atoms (which will be escaped and converted to binaries for presentation to handlers)
 
 
-## gen_json ##
-
-jsx is implemented as a set of scanners that produce tokens consumed be functions that transform them into various representations. `gen_json` is an interface to allow arbitrary representations/actions to be taken upon scanning a json text or erlang term representation of a json text
-
-
-**the gen_json parser**
-
-`gen_json:parser(Mod)` -> `Result`
-
-`gen_json:parser(Mod, Args)` -> `Result`
-
-`gen_json:parser(Mod, Args, Opts)` -> `Result`
-
-types:
-
-* `Mod` = module()
-* `Args` = any()
-* `Opts` = see note below
-
-`Mod` is the callback module implementing the `gen_json` behaviour
-
-`Args` will be passed to `Mod:init/1` as is
-
-`Result` will be the return from `Mod:handle_event(end_json, State)`
-
-in general, `Opts` will be passed as is to the scanner. the scanner will be automatically selected based on input type. to specify a specific scanner, you may use the options `{parser, Parser}` where `Parser` can currently be one of `auto`, `encoder` or `decoder`. `auto` is the default behaviour, `encoder` will only accept erlang terms (as in the mapping detailed above) and `decoder` will only accept json texts. note that to parse naked erlang terms as json, you MUST specify `{parser, encoder}`. more scanners may be added in the future
-
-
-modules that implement the `gen_json` behaviour must implement the following two functions
-
-
-**init**
-
-produces the initial state for a gen_json handler
-
-`init(Args)` -> `InitialState`
-
-types:
-
-* `Args` = `any()`
-* `InitialState` = `any()`
-
-`Args` is the argument passed to `gen_json/2` above as `Args`. when `gen_json/1` is called, `Args` will equal `[]` 
-
-
-**handle_event**
-
-`handle_event/2` will be called for each token along with the current state of the handler and should produce a new state
-
-`handle_event(Event, State)` -> `NewState`
-
-types:
-
-* `Event` =
-    - `start_object`
-    - `end_object`
-    - `start_array`
-    - `end_array`
-    - `end_json`
-    - `{key, list()}`
-    - `{string, list()}`
-    - `{integer, integer()}`
-    - `{float, float()}`
-    - `{literal, true}`
-    - `{literal, false}`
-    - `{literal, null}` 
-* `State` = `any()`
-
-`Event` types are detailed in the mapping section, above. any cleanup in your handler should be done upon receiving `end_json` as it will always be the last token received
-
-
 ## acknowledgements ##
 
 paul davis, lloyd hilaiel, john engelhart, bob ippolito, fernando benavides and alex kropivny have all contributed to the development of jsx, whether they know it or not

src/gen_json.erl

@@ -1,80 +0,0 @@
-%% The MIT License
-
-%% Copyright (c) 2011 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.
-
-
--module(gen_json).
-
--export([behaviour_info/1]).
--export([parser/1, parser/2, parser/3]).
--export([handle_event/2, init/1]).
-
-
--type events() :: [event()].
--type event() :: start_object
-    | end_object
-    | start_array
-    | end_array
-    | end_json
-    | {key, list()}
-    | {string, list()}
-    | {integer, integer()}
-    | {float, float()}
-    | {literal, true}
-    | {literal, false}
-    | {literal, null}.
-
--type opts() :: [opt()].
--type opt() :: loose_unicode
-        | escape_forward_slashes
-        | explicit_end
-        | {parser, auto} | {parser, encoder} | {parser, decoder} | {parser, function()}.
-
--export_type([events/0, event/0, opts/0, opt/0]).
-
-
-behaviour_info(callbacks) -> [{init, 0}, {handle_event, 2}];
-behaviour_info(_) -> undefined.
-
-
-parser(F) -> parser(F, []).
-
-parser(F, Opts) when is_function(F, 1) -> parser(?MODULE, {F, undefined}, Opts);
-parser({F, State}, Opts) when is_function(F, 2) -> parser(?MODULE, {F, State}, Opts);
-parser(Mod, Args) -> parser(Mod, Args, []).
-
-parser(Mod, Args, Opts) when is_atom(Mod), is_list(Opts) ->
-    case proplists:get_value(parser, Opts, auto) of
-        auto ->
-            fun(Input) when is_list(Input) -> (jsx_encoder:encoder(Mod, Mod:init(Args), Opts))(Input)
-                ; (Input) when is_binary(Input) -> (jsx_decoder:decoder(Mod, Mod:init(Args), Opts))(Input)
-            end
-        ; encoder ->
-            fun(Input) -> (jsx_encoder:encoder(Mod, Mod:init(Args), Opts))(Input) end
-        ; decoder ->
-            fun(Input) -> (jsx_decoder:decoder(Mod, Mod:init(Args), Opts))(Input) end
-    end.
-
-
-handle_event(Event, {F, undefined}) -> F(Event), {F, undefined};
-handle_event(Event, {F, State}) -> {F, F(Event, State)}.
-
-init(State) -> State.

src/jsx.app.src

@@ -4,7 +4,6 @@
     {vsn, "1.0rc"},
     {modules, [
         jsx,
-        gen_json,
         jsx_encoder,
         jsx_decoder,
         jsx_to_json,

src/jsx.erl

@@ -42,7 +42,7 @@
 
 to_json(Source) -> to_json(Source, []).
 
-to_json(Source, Opts) -> jsx_to_json:to_json(Source, Opts ++ [{parser, encoder}]).
+to_json(Source, Opts) -> jsx_to_json:to_json(Source, Opts).
 
 %% old api, alias for to_json/x
 
@@ -55,8 +55,7 @@ term_to_json(Source, Opts) -> to_json(Source, Opts).
 
 format(Source) -> format(Source, []).
 
-format(Source, Opts) ->
-    jsx_to_json:to_json(Source, Opts ++ [{parser, decoder}]).
+format(Source, Opts) -> jsx_to_json:to_json(Source, Opts).
 
 
 -spec to_term(Source::binary()) -> any().
@@ -64,7 +63,7 @@ format(Source, Opts) ->
 
 to_term(Source) -> to_term(Source, []).
 
-to_term(Source, Opts) -> jsx_to_term:to_term(Source, Opts ++ [{parser, decoder}]).
+to_term(Source, Opts) -> jsx_to_term:to_term(Source, Opts).
 
 %% old api, alias for to_term/x
 
@@ -158,7 +157,7 @@ parse_tests([], _Dir, Acc) ->
 
 decode(JSON, Flags) ->
     try
-        case (gen_json:parser(?MODULE, [], Flags))(JSON) of
+        case (jsx_decoder:decoder(?MODULE, [], Flags))(JSON) of
             {incomplete, More} ->
                 case More(<<" ">>) of
                     {incomplete, _} -> {error, badjson}
@@ -172,7 +171,7 @@ decode(JSON, Flags) ->
 
     
 incremental_decode(<<C:1/binary, Rest/binary>>, Flags) ->
-	P = gen_json:parser(?MODULE, [], Flags ++ [explicit_end]),
+	P = jsx_decoder:decoder(?MODULE, [], Flags ++ [explicit_end]),
 	try incremental_decode_loop(P(C), Rest)
 	catch error:badarg -> io:format("~p~n", [erlang:get_stacktrace()]), {error, badjson}
 	end.

src/jsx_to_json.erl

@@ -38,8 +38,10 @@
 
 -spec to_json(Source::(binary() | list()), Opts::opts()) -> binary().
     
-to_json(Source, Opts) when is_list(Opts) ->
-    (gen_json:parser(?MODULE, Opts, jsx_utils:extract_opts(Opts)))(Source).
+to_json(Source, Opts) when is_list(Source) andalso is_list(Opts) ->
+    (jsx_encoder:encoder(?MODULE, init(Opts), Opts))(Source);
+to_json(Source, Opts) when is_binary(Source) andalso is_list(Opts) ->
+    (jsx_decoder:decoder(?MODULE, init(Opts), Opts))(Source).
 
 
 

src/jsx_to_term.erl

@@ -37,7 +37,7 @@
 -spec to_term(Source::(binary() | list()), Opts::opts()) -> binary().
     
 to_term(Source, Opts) when is_list(Opts) ->
-    (gen_json:parser(?MODULE, Opts, jsx_utils:extract_opts(Opts)))(Source).
+    (jsx_decoder:decoder(?MODULE, init(Opts), Opts))(Source).
 
 
 

src/jsx_utils.erl

@@ -23,7 +23,7 @@
 
 -module(jsx_utils).
 
--export([parse_opts/1, extract_opts/1]).
+-export([parse_opts/1]).
 -export([nice_decimal/1]).
 -export([json_escape/2]).
 
@@ -49,22 +49,6 @@ parse_opts(_, _) ->
     {error, badarg}.
 
 
-extract_opts(Opts) ->
-    extract_parser_opts(Opts, []).
-
-extract_parser_opts([], Acc) -> Acc;     
-extract_parser_opts([{K,V}|Rest], Acc) ->
-    case lists:member(K, [loose_unicode, escape_forward_slash, explicit_end, parser]) of
-        true -> extract_parser_opts(Rest, [{K,V}] ++ Acc)
-        ; false -> extract_parser_opts(Rest, Acc)
-    end;
-extract_parser_opts([K|Rest], Acc) ->
-    case lists:member(K, [loose_unicode, escape_forward_slash, explicit_end]) of
-        true -> extract_parser_opts(Rest, [K] ++ Acc)
-        ; false -> extract_parser_opts(Rest, Acc)
-    end.
-
-
 
 %% conversion of floats to 'nice' decimal output. erlang's float implementation 
 %%   is almost but not quite ieee 754. it converts negative zero to plain zero 

src/jsx_verify.erl

@@ -36,9 +36,12 @@
 
 -spec is_json(Source::(binary() | list()), Opts::opts()) -> binary().
     
-is_json(Source, Opts) when (is_binary(Source) andalso is_list(Opts))
-        orelse (is_list(Source) andalso is_list(Opts)) ->
-    try (gen_json:parser(?MODULE, Opts, jsx_utils:extract_opts(Opts)))(Source)
+is_json(Source, Opts) when is_list(Source) andalso is_list(Opts) ->
+    try (jsx_encoder:encoder(?MODULE, init(Opts), Opts))(Source)
+    catch error:badarg -> false
+    end;
+is_json(Source, Opts) when is_binary(Source) andalso is_list(Opts) ->
+    try (jsx_decoder:decoder(?MODULE, init(Opts), Opts))(Source)
     catch error:badarg -> false
     end.