abstract syntax and syntactic sugar

Hi all,

in another thread [1], Enrico wrote something that got me thinking:

 > A “macro” has to have anyway a syntactic definition as well in the 
abstract syntax.

My first reaction was "of course not!", but then I think I understood 
where Enrico is coming from.

If we consider the abstract syntax as the "data model" on which the 
semantics is defined, then syntactic sugar or macros have no place in 
it. It should contain only the basic constructs that the (concrete) 
syntactic sugar and macros expand to. Note that the wording of RDF 
Concepts 1.1 strongly hints towards this interpretation : "This document 
defines an abstract syntax (a data model)".

If, on the other hand, we consider the abstract syntax as a syntax (!), 
i.e. an abstraction of the different concrete syntaxes that we have, 
then including macros in it make sense. Indeed, even though some 
concrete syntaxes have no syntactic sugar (N-Triples), some "macros" 
exist across multiple concrete syntaxes (collections, a.k.a. lists, have 
shortcut notations in RDF/XML, Turtle/TriG and JSON-LD). Having a common 
abstraction for them could be useful. (In fact, this resonates with a 
discussion Gregg and I had during TPAC 2022 about JSON-LD's internal 
representation).

My goal here is not to argue who's wrong or right: as explained above, I 
see value in both positions. I just wanted to share my realization with 
others, so that we do not talk/write past each other just because we 
have slightly different expectations of what the "abstract syntax" 
should or should not be.

   best

[1] https://www.w3.org/mid/C97CE6FB-4CC2-4E94-91E8-6BCEC64CFCD2@inf.unibz.it