Re: Could metatables easily be faster?

[Hugo Musso Gualandi <hgualandi@...>]

> Such a benchmark would require a substantial time investment, while 
> someone familiar with Lua's implementation may highlight a problem 
> which is not performance-dependent.

You might not realize it, but you already are more familiar with the 
implementation than you think ;) One nice thing about Lua having a 
small implementation is that it is not that difficult to wrap your head 
around the internals workings of the interpreter.

I encourage you to experiment what happens if you change metatables to 
use integer indices. For the purposes of the experiment, it doesn't 
have to be a well rounded patch. You can make something super hacky.

The main question I have is whether we would get a performance boost 
for the integer keys, vs hashing an interned short string. When we use 
a short string as a key, we don't need to recompute the hash every time 
because the hash is already pre-computed and stored inside the string 
object. The only part that is different is the logic for getting the 
value from the hash part vs from the array part.

-- Hugo