Re: Praise of Lua from a game developer

[Petri Häkkinen <petrih3@...>]

On 26.7.2012, at 16.23, Pierre-Yves Gérardy wrote:

> On Wed, Jul 25, 2012 at 8:57 PM, Petri Häkkinen <petrih3@gmail.com> wrote:
> 
>> iOS and game consoles do not currently allow modifying code pages when the app is running, so LuaJIT can’t be used on those.
> 
> This is not true. You can use LuaJIT in interpreter mode on iOS and
> (some if not all) major consoles. The LuaJIT interpreter is, on average, 2
> to 3 times faster than the PUC interpreter (based on the benchmarks of
> the LuaJIT site).

Sorry I should have been more specific: I meant that I can't use JIT compilation on iOS. Yeah, I've heard that people have been using the optimized LuaJIT interpreter successfully on iOS which gives me some hope with the port (vanilla Lua is pretty fast already but there's lots of Lua code in Grimrock). 

> 
>> Unfortunately merging upvalues/locals of patched functions is a nontrivial problem and I’m not even sure if it can be solved without changing Lua in some way.
> 
> Lua 5.2 has debug.upvaluejoin() for that purpose. I don't think it can
> be done in vanilla Lua 5.1 (hence, LuaJIT).

This is very interesting. I haven't been following 5.2 that closely. Thank you!

Anyone know if it's possible to back port upvaluejoin() into LuaJIT?

--Petri