lua_islightuserdata[-0, +0, –] int lua_islightuserdata (lua_State *L, int index); Returns 1 if the value at the given index is a light userdata, and 0 otherwise.

lua_isinteger[-0, +0, –] int lua_isinteger (lua_State *L, int index); Returns 1 if the value at the given index is an integer (that is, the value is a number and is represented as an integer), and 0 otherwise.

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.

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

lua_isboolean[-0, +0, –] int lua_isboolean (lua_State *L, int index); Returns 1 if the value at the given index is a boolean, and 0 otherwise.

lua_Integer typedef ... lua_Integer; The type of integers in Lua. By default this type is long long, (usually a 64-bit two-complement integer), but that can be changed to long or int (usually a 32-bit two-complement integer). (See LUA_INT_TYPE in luaconf.h.) Lua also defines the constants LUA_MININTEGER and LUA_MAXINTEGER, with the minimum and the maximum values that fit in this type.

lua_insert[-1, +1, –] void lua_insert (lua_State *L, int index); Moves the top element into the given valid index, shifting up the elements above this index to open space. This function cannot be called with a pseudo-index, because a pseudo-index is not an actual stack position.

lua_Hook typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar); Type for debugging hook functions. Whenever a hook is called, its ar argument has its field event set to the specific event that triggered the hook. Lua identifies these events with the following constants: LUA_HOOKCALL, LUA_HOOKRET, LUA_HOOKTAILCALL, LUA_HOOKLINE, and LUA_HOOKCOUNT. Moreover, for line events, the field currentline is also set. To get the value of any other field in ar, the hook must call lua_getinfo. For ca

lua_getuservalue[-0, +1, –] int lua_getuservalue (lua_State *L, int index); Pushes onto the stack the Lua value associated with the full userdata at the given index. Returns the type of the pushed value.

lua_getupvalue[-0, +(0|1), –] const char *lua_getupvalue (lua_State *L, int funcindex, int n); Gets information about the n-th upvalue of the closure at index funcindex. It pushes the upvalue's value onto the stack and returns its name. Returns NULL (and pushes nothing) when the index n is greater than the number of upvalues. For C functions, this function uses the empty string "" as a name for all upvalues. (For Lua functions, upvalues are the external local variables that the function us