Re: Please review: syntactic sugar and polishing (ISSUE-54, ISSUE-56, ISSUE-59, ISSUE-60)

There are trade-offs to offering syntactic sugar, I would like the group to
consciously consider the trade-offs and take a position. I think the core
tradeoff is a simple spec, with a single way to perform a task, vs a
"sugared" spec with more wrinkles but more concise for common cases. There
are implementation and education costs to these wrinkles. Personally, I
think it makes sense to avoid the sugar in 1.0 of the spec, but if the
consensus is towards sugar in 1.0 then I could go along with that.


> ISSUE-54: Simpler constant-valued term maps
> http://www.w3.org/2001/sw/rdb2rdf/track/issues/54
>
> Instead of this:
>
>    [] rr:predicateMap [ rr:predicate ex:foo ].
>
> you now have to write one of these two forms:
>
>    [] rr:predicateMap [ rr:constant ex:foo ].
>    [] rr:predicate ex:foo.
>

I think this is a good change (assuming we want a sugared spec) because
constant predicates seem to be the norm for the use cases I have seen.


ISSUE-56: Default termType for template-valued term maps should be IRI
> http://www.w3.org/2001/sw/rdb2rdf/track/issues/56
>

This makes sense to me.

The default term type is now always rr:IRI, except for rr:column in an
> object map.
>

I need to think this through more. Seems this is a bit different than
ISSUE-56?


> ISSUE-59: Syntactic sugar for triples maps that only have a single
> predicate-object map
> http://www.w3.org/2001/sw/rdb2rdf/track/issues/59
>

I am curious what use-case you have in mind for this. Seems to me that this
is primarily useful for simple examples or getting started because I expect
most mappings to involve multiple columns from a table. From that
perspective this does not look like a useful change to me.


> ISSUE-60: Syntactic sugar for the simple case of logical tables
> http://www.w3.org/2001/sw/rdb2rdf/track/issues/60
>
> Instead of this:
>
>    <#TriplesMap1> rr:logicalTable [ rr:tableName "EMP" ].
>
> you can now also write this equivalent form:
>
>    <#TriplesMap1> rr:tableName "EMP".
>

I think this is a good change (assuming we want a sugared spec).

-David