How to decode a map with optional fields elegantly?

[arianvp]

Currently CBORG allows peeking token types but I was wondering how hard it would be to peek values as well?

My usecase is I need to deserialise a canonical CBOR Map (so keys are sorted; that's nice) but some keys are optional; so I'd like to elegantly write a decoder that can decode a map with optional fields. any idea how to do so?

I want to decode a CBOR map into a Haskell record; each key can have a different type for the value; so i can't decode to a HashMap first or something.

[ghost]

I think if #219 gets implemented you'll be able to do what you want.