Add erlang binding (#54)

* add erlang support

* add erlang support for windows

* add erlang ci for linux and windows

erlang/src/ruapu.app.src

@@ -0,0 +1,14 @@
+{application, ruapu,
+ [{description, "ruapu erlang/otp binding"},
+  {vsn, "0.1.0"},
+  {registered, []},
+  {applications,
+   [kernel,
+    stdlib
+   ]},
+  {env,[]},
+  {modules, []},
+
+  {licenses, ["MIT"]},
+  {links, []}
+ ]}.

erlang/src/ruapu.erl

@@ -0,0 +1,32 @@
+-module(ruapu).
+-export([rua/0, supports/1]).
+
+-ifdef(TEST).
+-include_lib("eunit/include/eunit.hrl").
+-endif.
+
+%% @doc
+%%
+%% Get a list of supported features.
+-spec rua() -> {ok, [string()]} | {error, string()}.
+rua() ->
+    ruapu_nif:rua().
+
+%% @doc
+%%
+%% Check if a feature is supported.
+-spec supports(atom() | string() | binary()) -> boolean().
+supports(ISA) ->
+    ruapu_nif:supports(ISA).
+
+-ifdef(EUNIT).
+rua_test() ->
+    ?assertMatch({ok, _}, rua()).
+
+supports_test() ->
+    ?assert(supports(<<"binary_non_exists_feature">>) =:= false),
+    ?assert(supports("string_non_exists_feature") =:= false),
+    ?assert(supports(atom_non_exists_feature) =:= false),
+    {ok, Features} = rua(),
+    ?assert(lists:all(fun(Feature) -> supports(Feature) end, Features)).
+-endif.

erlang/src/ruapu_nif.erl

@@ -0,0 +1,30 @@
+-module(ruapu_nif).
+-export([supports/1, rua/0]).
+
+-on_load(init/0).
+
+-define(APPNAME, ruapu).
+-define(LIBNAME, ruapu_nif).
+
+init() ->
+    SoName = case code:priv_dir(?APPNAME) of
+        {error, bad_name} ->
+            case filelib:is_dir(filename:join(["..", priv])) of
+                true ->
+                    filename:join(["..", priv, ?LIBNAME]);
+                _ ->
+                    filename:join([priv, ?LIBNAME])
+            end;
+        Dir ->
+            filename:join(Dir, ?LIBNAME)
+    end,
+    erlang:load_nif(SoName, 0).
+
+not_loaded(Line) ->
+    erlang:nif_error({not_loaded, [{module, ?MODULE}, {line, Line}]}).
+
+supports(_ISA) ->
+    not_loaded(?LINE).
+
+rua() ->
+    not_loaded(?LINE).