You still can use external libraries for that (e.g., struct and lpack).
We thought that this basic functionallity was a good trade-off beween
usefuleness and simplicity for the standard library. (Thanks to
Daurnimator for the suggestion.)
-- Roberto
Thanks for taking my suggestion on board!
I'm wondering if anyone has had time to re-implement struct or lpack in pure lua yet?
Ben Kelly's (a.k.a. ToxicFrog) vstruct might be an interesting place to start...