Serialize support

[wolfv]

I saw the deserialize support and was wondering if you have plans to add a marked_yaml::to_string( ... ) functionality as well (serializing to YAML)? If I understand correctly, this functionality isn't implemented yet, right?

We are also looking for ways to serialize to YAML and collapse some maps to inline-maps. Not sure if you know whether that would be doable?

[kinnison]

I would not object to a serialisation implementation, but I've never been quite sure what the best approach would be.

For example, attempting to maintain the marks during serialisation might be very very hard. If you're just after "I have a struct which contains some Spanned<T> which needs serialising via the underlying yaml library used then I think it'd be reasonable to implement the serialize trait for Spanned<T> to just fall through to the inner T and then we can expose a serialisation function which doesn't leak the underlying yaml-rust2 situation.

[kinnison]

As for serialising MarkedNode etc. I guess that would have to happen only if you think that's appropriate for round-tripping -- I'd be content with an expectation that people would convert things to a proper data structure before eventually wanting to re-serialize.