Re: Question about Lua performance (locals vs globals)

[Bryan White <bryan@...>]

David Given wrote:
> They actually work by totally different mechanisms. Lua locals are
> lexically scoped true variables, and exist on the Lua stack[1]
> internally. When you access a local, it's referred to directly[2]
> without any table lookup happening at all. Lua globals aren't really
> variables at all; they're simply syntactic sugar for doing table
> accesses on _G. This:

It seems that asking script coders to be aware of such issues and 
optimize their code for them is less than optimal.

I think that globals should be handled differently.  Perhaps there 
should be an internal 'C' array of globals, maybe just pointers to the 
internals of the _G table.  Then compiled references to said globals 
would just contain indexes into the array.  If _G members are removed, 
then the corresponding global indexes would have to be marked nil 
somehow.  I don't know the lua internals so I have no idea what 
complications this would introduce.  I suspect it would have to be a 
'Next Generation' feature.


--
Bryan White