YARRRML Lessons learned

[bjdmeest]

Hi all, this is just a way to present some lessons learned we had when developing YARRRML: a DSL that translates to (R2)RML, a mapping langauge that converts heterogeneous data sources to RDF. Although the goal of YARRRML (a developer-friendly DSL to write RML documents that happen to be in Turtle) is different from YAML-LD, it is at least a bit related :). Some things we encountered:

• Using ~ as a convencience to 'tag' specific values, e.g., to specify, when mapping a value to a node, to map it to a literal (http://example.com/homepage~literal => "http://example.com/homepage") or an iri (http://example.com/homepage~iri => <http://example.com/homepage>). (we did not use _ since this might confuse users with blank nodes somehow), see eg https://rml.io/yarrrml/spec/#tabs-19. Also related to #55
• A limitation of YAML we encountered was not being able to refer to another YAML-document. We had to include a mechanism to 'combine' multiple YAML files and handle external values (see https://github.com/RMLio/yarrrml-parser#yarrrml-parser-1)

If it makes sense to take this into account for YAML-LD, happy to continue the discussion! If irrelevant, feel free to close this without further ado ;)

[VladimirAlexiev]

related to #19

[ioggstream]

Not advocating the use of $(DANGEROUS BASH COMMAND) in documents :P