Datatypes?

Q: What about data types in ddot.it?

A: There are no data types in ddot.it. Users can use, e.g., JSON primitive syntax to express data types. RDF Turtle syntax works also. Both syntaxes need to be interpreted by higher layers. It looks ugly, but it works.

Serializing to ddot.it

Q: Is it easy to dump data to ddot.it syntax?

A: Yes. In most scenarios, you have total control over your small relation vocabulary. Check each value for the character sequences that carry ddot.it syntax in its slot:

  • .. markers in subjects and relations (would be re-parsed as triple markers),

  • newlines (would be re-parsed as a shorter value),

  • ,, markers in objects (would be re-parsed as start of a meta block),

  • ;; in inline meta-objects (would be re-parsed as a meta separator),

  • !!off / !!on (in any command spelling) anywhere in any value — these two pre-parse commands act anywhere on a line.

If any of these occur, write the value as a !!block command filling that slot. Since !!block may fill any field — subject, relation, object, meta-relation, meta-object, meta-text — every string value can be serialized this way. Other in-text !! sequences are harmless: a strict parser keeps them as part of the field’s text.

Namespaces

Q: Can I use namespaces like in RDF or XML?

A: See also https://ddot.it/rdf.html. In short, you can, but you usually don’t need to.

Using Namespaces

In all strings, the namespace syntax with prefix + colon can be used. E.g. foaf:knows is a valid ddot.it relation.

Declaring Namespaces

– so that they can be resolved A ‘natural’ option in ddot.it would be

Example
rdf ..prefix.. http://www.w3.org/1999/02/22-rdf-syntax-ns#
dc ..prefix.. http://purl.org/dc/elements/1.1/
ex ..prefix.. http://example.org/stuff/1.0/

This is no longer hypothetical: prefix is a declared built-in relation, with its own URI and semantics — when a name like A:foo is read, A: is replaced by the prefix’s value.

The open question of whether it should be spelled ddot:prefix is settled: it is plain prefix. Qualifying it would need a prefix declaration to read the prefix declaration, and ddot.it keeps its built-ins unqualified. The ddot prefix itself is declared in the vocabulary for use in ordinary triples.

Prefixes matter only when exporting to RDF. A ddot.it triple base that is never mapped to RDF can use foaf:knows as an opaque relation name and never declare anything — to the parser it is just text.

References

  • The Pomsky portable regex syntax seems smart