I want to write out strings to a file and read them back in again, in an
ASCII-safe way. I'm writing them out with string.format("%q"), because
it's cheap and easy[*], but now I need to read them back in again.
Actually going through the string and parsing the escapes seems like a
lot of work. A faster but much scarier alternative is to wrap the string
with 'return (<string>' and compile and execute it in a restricted
environment.
Given that the interpreter already contains code to safely turn an
escaped string into a Lua string, there must be a better way --- what is it?