Yeah, this is the way I'll do it, what I was trying to point is that someones code not supporting 64 bits is not the languages fault unless it guarantees 64 bit correctness and that if a language is reasonably powerful ( like, i.e., 6502 assembler? ) one can and should code around its limitations ( if one calls himself a programmer ). Having programmed professionally in several 8 bit architectures, in which you even have to code around lack of multiplication ( and you did floating point math if needed, although normally using a library , which someone had to write ) I find the lack of 64 bit ints in a language as powerful as lua a small inconvenience. Haven't search a lot, but my bet is there are bignum libraries around, and wrapping something like GMP for lua, or writing a library for 64 bits int, seems to be aproachable. I did not suggest the usage of a library because for something as limited as a parser it seems easier to jut include a couple of classes and avoid the external dependency.