3.4.10 – Function Calls A function call in Lua has the following syntax: functioncall ::= prefixexp args In a function call, first prefixexp

math.abs (x) Returns the absolute value of x. (integer/float)

luaL_prepbuffsize[-?, +?, m] char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz); Returns an address

lua_pushnil[-0, +1, –] void lua_pushnil (lua_State *L); Pushes a nil value onto the stack.

string.lower (s)