Function ll_require

ThirdParty/lua/lua/loadlib.c:557–578

static int ll_require (lua_State *L) {
  const char *name = luaL_checkstring(L, 1);
  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
  lua_getfield(L, 2, name);  /* _LOADED[name] */
  if (lua_toboolean(L, -1))  /* is it there? */
    return 1;  /* package is already loaded */
  /* else must load package */
  lua_pop(L, 1);  /* remove 'getfield' result */
  findloader(L, name);
  lua_pushstring(L, name);  /* pass name as argument to module loader */
  lua_insert(L, -2);  /* name is 1st argument (before search data) */
  lua_call(L, 2, 1);  /* run loader to load module */
  if (!lua_isnil(L, -1))  /* non-nil return? */
    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
  if (lua_getfield(L, 2, name) == LUA_TNIL) {   /* module set no value? */
    lua_pushboolean(L, 1);  /* use true as result */
    lua_pushvalue(L, -1);  /* extra copy to be returned */
    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
  }
  return 1;
}

/* }====================================================== */