lua_pushlightuserdata[-0, +1, –] void lua_pushlightuserdata (lua_State *L, void *p); Pushes a light userdata onto the stack. Userdata represent C values in Lua. A light userdata represents a pointer, a void*. It is a value (like a number): you do not create it, it has no individual metatable, and it is not collected (as it was never created). A light userdata is equal to "any" light userdata with the same C address.

lua_isfunction[-0, +0, –] int lua_isfunction (lua_State *L, int index); Returns 1 if the value at the given index is a function (either C or Lua), and 0 otherwise.

collectgarbage ([opt [, arg]]) This function is a generic interface to the garbage collector. It performs different functions according to its first argument, opt: "collect": performs a full garbage-collection cycle. This is the default option. "stop": stops automatic execution of the garbage collector. The collector will run only when explicitly invoked, until a call to restart it. "restart": restarts automatic execution of the garbage collector. "count": returns the total memory

string.lower (s)

math.maxinteger

lua_pushthread[-0, +1, –] int lua_pushthread (lua_State *L); Pushes the thread represented by L onto the stack. Returns 1 if this thread is the main thread of its state.

lua_isstring[-0, +0, –] int lua_isstring (lua_State *L, int index); Returns 1 if the value at the given index is a string or a number (which is always convertible to a string), and 0 otherwise.

luaL_argerror[-0, +0, v] int luaL_argerror (lua_State *L, int arg, const char *extramsg); Raises an error reporting a problem with argument arg of the C function that called it, using a standard message that includes extramsg as a comment: bad argument #arg to 'funcname' (extramsg) This function never returns.

lua_register[-0, +0, e] void lua_register (lua_State *L, const char *name, lua_CFunction f); Sets the C function f as the new value of global name. It is defined as a macro: #define lua_register(L,n,f) \ (lua_pushcfunction(L, f), lua_setglobal(L, n))

math.ceil (x) Returns the smallest integral value larger than or equal to x.