How to read and write OsPaths without interpreting them?

I'm trying to read and write lists of OsPaths (actually just PosixPaths in case that matters) to files. I want to avoid doing any conversion or interpretation if possible---just treat the paths as opaque bytestrings separated by `\NUL`.

I see that I could use `encodeFS` and `decodeFS`, but 1) that's incompatible with Attoparsec (annoyingly, the `Parser` monad isn't a transformer), 2) it forces IO into a lot of otherwise pure code, and 3) the extra round-trip seems more likely to introduce encoding bugs than prevent them.

I'm about to try breaking into the hidden modules and using the raw constructors. But is there a more recommended way to read/write PosixPaths?

One idea that comes to mind is adding a Binary/Bytable instance? I haven't looked into that before. But a trivial instance that just wraps/unwraps the constructor seems like it would be equivalent to exposing the constructor itself.

Edit: also, thanks for taking on this OsPath thing! I'm not well versed in low level encodings and am glad someone is working on it. I would offer to help to the extent I can without breaking anything. I'm working on `Arbitrary` instances to check that my code can round-trip trees of OsPaths to folders on disk. Maybe a version of those could end up in the library and help identify bugs?