Expose and document read_data_item.

[dvc94ch]

Hi,

I'm using read_data_item directly and it would be cool if it were public.

pub(crate) fn decode(bytes: Vec<u8>) -> Result<Ipld, IpldError> {
    let mut d = Decoder::from_bytes(bytes);
    let cbor: Cbor = d.read_data_item(None)?;
    cbor_to_ipld(cbor)
}

[BurntSushi]

Thanks for reaching out. Unfortunately, this function should definitely never be exported in its current form. It's an internal implementation detail whose correctness is dependent on its parameters (which this PR does not document).

Separate from that, this project is unmaintained. Please see the top of the README: https://github.com/BurntSushi/rust-cbor/blob/master/README.md

[dvc94ch]

The problem with serde-cbor is that it doesn't support tags which is required for encoding/decoding ipld.

[BurntSushi]

Yes, I'm aware of the shortcoming. But that doesn't mean I'm going to maintain this. Sorry. You might consider contributing tag support to serde-cbor, or forking it and adding your own. (I don't know whether they've officially blocked tag support on specialization, but you should be able to use a similar hack that this crate uses to support tags in serde.)