I have been coming across information about Merkledags and IPLDS that seems conflicting or overlapping.
When I first started looking into IPFS I quickly learnt about Merkle trees and how IPFS uses a slight modification of that…instead of trees, we have DAGs, hence the Merkledag. The link about Merkledag on the documentation here https://docs-beta.ipfs.io/concepts/merkle-dag/#further-resources basically presented it as the underlying data structure of IPFS.
I think I recently came across a section of the docs (and for the life of me I can’t find the link) where it was stated that Merkledag are being deprecated in favour of IPLD. But even without finding a reference to that claim, the first texts on the IPLD website here https://ipld.io/ states that IPLD is the data model of the content-addressable web - but is that what the Markledag is supposed to be?
I will appreciate if someone knowledgeable about these concepts can help clarify and disambiguate between Markledags and IPLD and how they fit into IPFS.
Would I be correct to say IPLD is still a Markledag? But Markledag with more structure? By more structure, I mean there is specification about what data the nodes in the dag should look like, how the links should look like etc?
IPLD is just an specification for Merkle-DAGs which allows to abstract many types of merkle dags and work with them. You may have seen that certain ipfs-merkledag-specific type is getting abstracted with IPLD, but as such, Merkle-DAGs remain.
I am just getting into IPLD-based development and have been trying to decide where to begin with new Go application code using embedded go-ipfs. In particular, the distinction between go-ipld-format and go-ipld-prime is somewhat confusing to me. From reading the go-ipld-legacy repo I gather that prime is the new way to do things, replacing legacy format-based code. Is that correct? I’d also like to use IPLD Schema as much as possible, and am slowly grokking how all these pieces fit together. A pointer to a minimal, but up-to-date IPLD Go code example would prove very helpful!
@crimeminister if you’re starting anything new with IPLD in Go then go-ipld-prime is definitely the right choice. At the moment there’s work going in to migrating older code to use go-ipld-prime and not a lot of work investing in building on top of the older libraries.
In terms of examples, looking through go-ipld-prime’s repo is probably the best start, there’s lots of docs littered throughout and the tests have lots of examples.
There’s a feature branch in go-ipfs that’s working to getting a migration for the bulk of the core code of go-ipfs migrated, it might be interesting: https://github.com/ipfs/go-ipfs/pull/7976 - see links and other PRs that merged into that branch.
(The forum isn’t allowing me to post more links so I’ll have to split up this response …)
