RE: lua-l Digest, Vol 3, Issue 7

[<jgiors@...>]

> -------- Original Message --------
> Date: Sat, 2 Oct 2010 09:33:04 +0200
> From: Petr ?tetiar <ynezz@true.cz>
> Subject: Re: Protocol Specification in Lua
> To: Lua mailing list <lua-l@lists.lua.org>
> Message-ID: <20101002073304.GC28423@ibawizard.net>
> Content-Type: text/plain; charset=us-ascii
> 
> John Passaniti <john@japanisshinto.com> [2010-10-01 14:53:18]:
> 
> Hi,
> 
> [snip]
> 
> > The generation of code from the protocol description isn't driven by a
> > fear of the efficiency of Lua.  It's driven by the fact that I don't
> > think Lua is going to be running on a 8-bit Freescale HCS08
> > microcontroller running at 24MHz anytime soon.  And the larger
> > platform the C code targets is a ColdFire that has about 16k of RAM
> > left over and about twice that in ROM.  Yes, I'm one of those embedded
> > systems guys who hangs out in this mailing list to remind everyone
> > that while Lua can go lots of places, it can't go everywhere.
> 
> It's a shame, you couldn't use Lua directly. Otherwise is quite easy and
> comfortable to send just compiled Lua table along with checksum over the UDP.
> In the short something like <size><bytecode><crc> in the packet. Imagine, that
> the Lua tables can contain functions, so the possibilities of such protocol
> are endless.
> 
> Back to your subject. I would take a look at Metalua, using it, you can easily
> generate your C protocol parser code for the Coldfire just by parsing your
> protocol specification in Lua.
> 
> -- ynezz

You might find the article "Lua as a Protocol Language" in Lua
Programming Gems useful, or at least interesting. It describes sending
Lua strings rather than compiled tables, but the basic idea is the same.

John Giors
Independent Programmer
Three Eyes Software
jgiors@ThreeEyesSoftware.com
http://www.ThreeEyesSoftware.com