Yes! Here is another half-backed one for your entertainment! Hurray!
I use general memoizers (those that work on functions with 0-M arguments returning 0-N values) fairly frequently. A string serialization approach can certainly work (though table and function argument handling gets a bit dicy). But in the profiling tests I've done, an implementation that stores the arguments in a tree of tables is often significantly faster. There's at least one such implementation already linked from the lua users wiki:
The argument tree approach can also be expanded to handle nil argument or nil return values; though doing so requires a small C-api function.
static int count_args(lua_State * L) {
lua_pushnumber(L,lua_gettop(L));
return 1;
}
The general memoizers I use in my own projects are written almost entirely in the C-API. But, if you have count_args, simpler, prettier Lua implementations are possible. Here's a demo of a count_args based M-to-N memoizer:
