Implement codegen for midi

[richard-uk1]

At the moment, the library only implements parsing. It could be extended to implement codegen/serialize/whatever you want to call it.

[Boscop]

Yes, that would be useful!

[Boscop]

It could be done with this:
https://github.com/Geal/cookie-factory
Which is like nom but for serializing.

[richard-uk1]

I'm gonna have a look at this now - I know more about streaming now so I might be able to write a better API.

[richard-uk1]

I'd recommend checking out https://github.com/RustAudio/rimd - it implements both serialization and deserialization of SMF (midi files) and a load of other stuff. I think if I worked on this lib I'd be duplicating functionality.