Strict ordering for DAG-CBOR-encoded map keys

[cdata]

This change proposes a fix for #492 . Ipld::Map keys are sorted according to the strictness guidelines in the DAG-CBOR spec when encoding them as DAG-CBOR.

[koivunej]

Thanks for reporting and offering a fix for this. The build is currently broken, will try to get to fixing that in near future.

I'm thinking the eventual solution is to have a newtype and comparator with expected PartialOrd implementation.. Do I understand this correctly, that String or Vec or [T] would sort correctly except that it doesn't consider the length as the first sort?

[koivunej]

Maybe it's because of RFC 8949 includes the sorting on the cbor serialized keys which start with the length information. Now it makes sense.

@cdata could you rebase this on top of master? The build was broken but now it should work.

[cdata]

Thanks for reporting and offering a fix for this. The build is currently broken, will try to get to fixing that in near future.

I'm thinking the eventual solution is to have a newtype and comparator with expected PartialOrd implementation.. Do I understand this correctly, that String or Vec or [T] would sort correctly except that it doesn't consider the length as the first sort?

Yes, I believe that analysis of the problem is correct.

The change has been rebased onto the latest master version.

[koivunej]

Thank you for the fix!

bors r+

[bors]

Build succeeded:

• ci