[DID Data Object References] I believe the proposed additions to the proposed ABNF are superfluous #119
Description
@talltree @ken-ebert I believe the proposed additions to the proposed ABNF (i.e. the "!" and "$" operators) are superfluous.
The current proposed ABNF specification (listed in the paper) already includes the "#" operator for deferencing any component of a DID Document that has a "#" anchor in it's id attribute. See use case 2a in w3c/did-resolution#32 for an example as well as Example D in w3c-ccg/did-spec#170 (comment)
This might similarly lead us to question why is the ";" operator is needed if we have the "#" operator? I think having both makes sense because the ";" operator can have a very different semantic meaning: see use cases 2b, 2c and 2d in w3c/did-resolution#32
Conclusion: This paper doesn't establish a strong rationale for adding "!" and "$" as new operators in DID ABNF grammar ...(apologies for sounded so brutal) but they appear to be "syntactic sugar" with no additional semantic value above what the "#" operator already provides.
As I state at the bottom of w3c/did-resolution#32 (comment),
The DID ABNF is more than a syntax specification ...more than a grammar...
The DID ABNF is an algebra for working with the DID Document associated with a DID.
Let's use it that way. We don't need to invent anything new or extra.
That is, we only need one "+" sign in our algebra (figuratively speaking) (aka "#" operator), not 3 IMO. Just like "+" is overloaded for integers, real numbers, strings, etc. in ordinary algebra/arithmetic, the "#" operator can similarly be applied to any component of a DID Document that has an id attribute containing a "#" anchor.