Is it possible to take a string and index it or get individual characters from it? Ideally, I would like to convert to/from bytes to ascii characters. It looks like Lua 5.1 supports this in the standard library, but as far as I can tell, Pico-8 doesn't include it.

EDIT: I notice that I can use the # symbol preceding a token to get its length, such as a table or array or string, but I still can't directly index it.

EDIT2: After thoroughly reading the manual as much as possible, it looks like my answer is to use the sub() function.

See also:

http://pico-8.wikia.com/wiki/Sub
https://www.lexaloffle.com/bbs/?tid=2420
https://www.lexaloffle.com/bbs/?tid=2978
https://www.lexaloffle.com/bbs/?tid=1819

Oh hey there's a wiki too, that's helpful. Thanks