Session Date/Time: 26 Jul 2024 22:30

cbor

Summary

The cbor working group met to discuss the status of several documents, including time tag, Gwema, EDN literal, CDDL more control, CBOR Pact, and CDE. The main point of contention was the ABNF specification for EDN literals, with a debate over a single-layer versus two-layer approach. CDDL more control seems ready to be shipped. CBOR Pact is approaching working group last call. Discussion on CDE highlighted the need for variability reduction and the concept of application profiles.

Key Discussion Points

EDN Literal ABNF: A lengthy debate ensued regarding whether to use a single-layer or two-layer ABNF approach for defining EDN literals. Arguments centered around ease of implementation, extensibility, and compatibility with existing tools and specifications. Concerns were raised regarding modifying the ABNF in flight versus fixing the tools. Horan voiced concerns about different seabor encodings being created due to implementations not having the same prefixes.
CDDL More Control: The group discussed the CDDL more control document, highlighting features like base64 encoding support, decimal number generation, and the printf control operator. Lawrence reported using the draft to verify CDDL in Eat and catching a number of errors, supporting its readiness.
CBOR Pact: CBOR Pact defines tags used to reference data within a constrained system. The primary remaining issue concerns how to handle unpacking errors. The group tentatively agreed to proceed to working group last call after resolving the unpack error.
CDE: Discussion focused on Deterministic CBOR Encoding, specifically aimed at variability reduction. Concerns were raised around the introduction of "profiles" in Seabor, the complexity of existing sections of RFC 88949, and whether CDE should itself be a profile. Basic serialization was introduced to handle the exclusion of indefinite length encoding for constrained use.

Decisions and Action Items

EDN Literal: The ABNF discussion for EDN literals will be continued on the mailing list with a time limit, after which a decision will be made. Carsten will post something to the list regarding next steps.
CDDL More Control: The group agreed to ship the CDDL more control document.
CBOR Pact: CBOR Pact will proceed to working group last call after addressing the unpack error.
Interim Meeting Schedule: The interim meeting schedule was verified.

Next Steps

Continue EDN literal ABNF discussion on the mailing list.
Address the unpack error in CBOR Pact and initiate working group last call.
Further discussion on CDE variability reduction and basic serialization on the mailing list.
Next interim meeting August 21st.