SCRIPT: Setup a custom _ENV for scripts to be executed inside + protect the Vivy table

src/Lib/Script/LuaContext.cc

@@ -19,7 +19,6 @@ LuaContext::LuaContext() noexcept
 
     loadString(libVivy.readAll().toStdString().c_str()); // Load the lib
     SampleObject::Register(L);                           // Load the C++ objects
-    swapEnv();                                           // Swap the _ENV
 }
 
 LuaContext::~LuaContext() noexcept
@@ -27,6 +26,12 @@ LuaContext::~LuaContext() noexcept
     lua_close(L);
 }
 
+void
+LuaContext::swapEnv() noexcept
+{
+    lua_setglobal(L, "vivy");
+}
+
 int
 LuaContext::exec() noexcept
 {
@@ -40,16 +45,20 @@ LuaContext::exec() noexcept
 int
 LuaContext::loadString(const char *str) noexcept
 {
-    if (luaL_loadstring(L, str) != LUA_OK)
+    if (luaL_loadstring(L, str) != LUA_OK) {
+        puts("Error loading string");
         return LUA_ERRERR;
+    }
     return exec();
 }
 
 int
 LuaContext::loadFile(const char *file) noexcept
 {
-    if (luaL_loadfile(L, file) != LUA_OK)
+    if (luaL_loadfile(L, file) != LUA_OK) {
+        puts("Error loading file");
         return LUA_ERRERR;
+    }
     return exec();
 }
 

src/Lib/Script/LuaContext.hh

@@ -28,10 +28,7 @@ private:
     int exec() noexcept;
 
     // Swap the env, needed before executing a user script!
-    void swapEnv() noexcept
-    {
-        loadString("_ENV = vivy\n");
-    }
+    void swapEnv() noexcept;
 };
 
 }

utils/rsc/lua/lib.lua

@@ -30,34 +30,46 @@ Iterable = enum {
     "SYLLABE"
 }
 
--- Table: reservedKeywords["keyword"] = "type"
-local reservedKeywords = {}
+-- Table: ReservedKeywords["keyword"] = "type"
+local ReservedKeywords = {
+    ["Vivy"] = "table"
+}
 
 -- Vivy global object construction
-vivy = {}
+Vivy = {
+    -- Standard libraries
+    ["math"]   = math,
+    ["string"] = string,
+    ["utf8"]   = utf8,
+    ["table"]  = table,
+
+    -- Custom things
+    ["Iterable"] = Iterable,
+}
 
-vivy.math     = math
-vivy.Iterable = Iterable
-vivy.Vivy     = vivy
-vivy.Version  = setmetatable({
+version = {
     ["MAJOR"] = 0,
     ["MINOR"] = 1,
     ["PATCH"] = 0,
     ["LABEL"] = "alpha",
-}, {
+}
+
+Vivy["Version"] = setmetatable(version, {
     __tostring = function ()
         return string.format("%d.%d.%d-%s",
-            vivy.Version.MAJOR,
-            vivy.Version.MINOR,
-            vivy.Version.PATCH,
-            vivy.Version.LABEL)
-    end,
-    __newindex = function (t, k, v)
-        if reservedKeywords[k] ~= nil then
-            error(k .. " is a reserved word")
-        else
-            rawset(t, k, v)
+            Vivy.Version.MAJOR,
+            Vivy.Version.MINOR,
+            Vivy.Version.PATCH,
+            Vivy.Version.LABEL)
     end
+})
+
+-- In case we are able to do the _ENV <- Vivy one day...
+Vivy["Vivy"] = Vivy
+
+Vivy = setmetatable(Vivy, {
+    __newindex = function (t, k, v)
+        error("you can't set new keys in the Vivy table")
     end
 })
 
@@ -65,3 +77,14 @@ vivy.Version  = setmetatable({
 io    = nil
 os    = nil
 debug = nil
+
+local _ENV = setmetatable(Vivy, {
+    __newindex = function (t, k, v)
+        -- Use the ReservedKeywords table here
+        if (k ~= "Vivy") then
+            rawset(t, k, v)
+        else
+            error("Try to assign something to the protected global symbol 'Vivy'")
+        end
+    end
+})