lua_setuservalue[-1, +0, –] void lua_setuservalue (lua_State *L, int index); Pops a value from the stack and sets it as the new value associated to the full userdata at the given index.

lua_setfield[-1, +0, e] void lua_setfield (lua_State *L, int index, const char *k); Does the equivalent to t[k] = v, where t is the value at the given index and v is the value at the top of the stack. This function pops the value from the stack. As in Lua, this function may trigger a metamethod for the "newindex" event (see §2.4).

package.loadlib (libname, funcname) Dynamically links the host program with the C library libname. If funcname is "*", then it only links with the library, making the symbols exported by the library available to other dynamically linked libraries. Otherwise, it looks for a function funcname inside the library and returns this function as a C function. So, funcname must follow the lua_CFunction prototype (see lua_CFunction). This is a low-level function. It completely bypasses the package

lua_xmove[-?, +?, –] void lua_xmove (lua_State *from, lua_State *to, int n); Exchange values between different threads of the same state. This function pops n values from the stack from, and pushes them onto the stack to.

package.cpath The path used by require to search for a C loader. Lua initializes the C path package.cpath in the same way it initializes the Lua path package.path, using the environment variable LUA_CPATH_5_3, or the environment variable LUA_CPATH, or a default path defined in luaconf.h.

lua_newstate[-0, +0, –] lua_State *lua_newstate (lua_Alloc f, void *ud); Creates a new thread running in a new, independent state. Returns NULL if it cannot create the thread or the state (due to lack of memory). The argument f is the allocator function; Lua does all memory allocation for this state through this function (see lua_Alloc). The second argument, ud, is an opaque pointer that Lua passes to the allocator in every call.

string.dump (function [, strip]) Returns a string containing a binary representation (a binary chunk) of the given function, so that a later load on this string returns a copy of the function (but with new upvalues). If strip is a true value, the binary representation may not include all debug information about the function, to save space. Functions with upvalues have only their number of upvalues saved. When (re)loaded, those upvalues receive fresh instances containing nil. (You can use th

3.3.1 – Blocks A block is a list of statements, which are executed sequentially: block ::= {stat} Lua has empty statements that allow you to separate statements with semicolons, start a block with a semicolon or write two semicolons in sequence: stat ::= ‘;’ Function calls and assignments can start with an open parenthesis. This possibility leads to an ambiguity in Lua's grammar. Consider the following fragment: a = b + c (print or io.write)('done') The grammar could see it in two ways:

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.

assert (v [, message]) Calls error if the value of its argument v is false (i.e., nil or false); otherwise, returns all its arguments. In case of error, message is the error object; when absent, it defaults to "assertion failed!"