Comments on Shacl-sparql Specification

I reviewed Peter's spec [1] and have some feedback. First, I think
this is a positive contribution and is complementary to Holger's spec.

This spec is a great example of how to define the semantics of a
language by translating that language into SPARQL. We can use this
approach with other language proposals.

The semantics of the language is not completely defined using SPARQL.
There is an upper control layer that is described informally. If we
make this upper control layer a little more flexible then we should be
able to support recursion.

The Extended Condition Language is somewhat low level and it would be
difficult to use by anyone who does not understand how it is
translated into SPARQL. I believe we need a higher level language for
the non-SPARQL user.

A more serious limitation is that there is no template mechanism,
which means that non-SPARQL users contain use extensions defined by
SPARQL users. We need a mechanism that allows either Core or Extended
conditions to be packaged and invoked like macros.

I have other comments and will put them in additional messages.

[1] https://www.w3.org/2014/data-shapes/wiki/Shacl-sparql

Received on Monday, 27 April 2015 19:50:40 UTC