pbLua based on 5.3 (work1) - it works!

[Ralph Hempel <rhempel@...>]

Just a brief note to say that I've successfully ported Lua 5.3 (work1) 
to the LEGO MINDSTORMS NXT platform, an extremely memory constrained 
ARM7 based device with only soft float support.

<http://www.hempeldesigngroup.com/lego/pblua>

I set up Lua to use int and float as the basic numeric types, and after 
a bit of struggle with my custom vfprintf() and getting bitten by the 
difference between fmodf() and modff() things worked pretty well.

On a simple loop iteration, I found that floats took about 3 times as 
long as ints, which is decent for soft floats.

The whole thing (including the NXT drivers and a binding to Lua) runs in 
about 138K of FLASH and I have 58K of the 64K of RAM available.

I do have to run the gc pretty aggressively because it's impossible to 
double the requested RAM more than once or twice after startup :-)

Thanks again to the three amigos for making one of the only tiny 
languages that will fill this niche. The alternatives (I tried them) 
were Forth and Scheme :-)

I'll go so far as to say it's the only tiny infix language I have found 
that's supported by a fantastic reference manual, book (PiL), and 
relatively noise free community mailing list.

Cheers, Ralph