Here''s something I did with lua

void CScriptWindow::AddButton(int id, char *caption, int width, int height, int x, int y, char *function){   CControl *control = new CControl();   control->id  = id;   control->cap = caption;   control->typ = "BUTTON";   control->xpos = x;   control->ypos = y;   control->wid = width;   control->heigh = height;   control->func = function;   control->hwnd = CreateWindow(control->typ, control->cap, WS_CHILD | WS_VISIBLE, control->xpos, control->ypos, control->wid, control->heigh, g_hwnd, (HMENU) control->id, g_hInstance, NULL);   ShowWindow(control->hwnd, SW_SHOW);   clist.push_back(control);}int l_AddButton(lua_State* luaVM){   char *caption = NULL;   int width = 0;   int height = 0;   int x = 0;   int y = 0;   char *function = 0;   int id = (int)lua_tonumber(luaVM, 1);   caption = (char *)lua_tostring(luaVM, 2);   width = (int)lua_tonumber(luaVM, 3);   height = (int)lua_tonumber(luaVM, 4);   x = (int)lua_tonumber(luaVM, 5);   y = (int)lua_tonumber(luaVM, 6);   function = (char *)lua_tostring(luaVM, 7);   lua_setglobal(luaVM, function);   theScriptWindow->AddButton(id, caption, width, height, x, y, function);   return 1;}then just used lua_register to register the function to LUA.. and calls from the script as AddButton 

You should check out a tool called tolua. It reads a simplified C/C++ header (usually with extension .pkg)and generates a C/C++ source file containing binding code. All you need to do is include the generated file in your project, and in your program initialize a lua_State and call the ''open''-function(s) that tolua generated (foo.pkg would yield, among other functions, one named tolua_foo_open(lua_State*), or something similar). After that the functions, classes, variables, etc. that were defined in the .pkg file will be available in Lua scripts run in the context of the lua_State were you ''opened'' them. It''s all very easy, and the website I linked to explains it better.

The only downside is that tolua currently doesn''t support Lua 5.0 (but from what I''ve read it''s in the works, so hopefully it''ll be out soon).

There are other (semi-)automated ways of binding C/C++ functions/classes/etc. to Lua. Links can be found in the Lua users Wiki, here (under ''Code Wrappers'').

And if you like, it''s pretty easy to create the interfaces yourself, similar to what Maega showed above.

There''s really not much need to have Lua stop and return control to the code that called it. Instead you can just provide functions for Lua to call, and have those functions do what you wanted the Lua function to exit back out for. Or you can set it up so the main program calls various Lua functions. Or to do what you said, have the Lua script sleep and return to the caller, and then presumably have the Lua script resume where it left off, you can use Lua''s coroutines.