justin2004/datething

Parse strings representing dates in SPARQL queries

datething

what

An Apache Jena value function wrapper around the parse function of Duckling (old). The parse function can parse a string like:

"the first Tuesday of October"

into

{:value "2014-10-07T00:00:00.000-07:00"
                                   :grain :day}

why

This allows one to use the parse function inside a SPARQL query to convert strings representing dates into xsd:dateTime values.

how

• have make and docker installed

• git clone this repo

• cd into it

• run make

• Then find target/datething-0.1.0-SNAPSHOT-standalone.jar and put it on your Apache Jena Fuseki classpath.

• Then invoke the parse function in a SPARQL query like so:

PREFIX datething: <java:datething.>
select *
WHERE {
  ?row xyz:when ?when_string .
  bind(strdt(datething:parse(?when_string),xsd:dateTime) as ?when)
}'

• you can also follow this blog post for more detail instructions.

notes / limitations

You can't parse a literal like: bind(strdt(datething:parse("12 oct 2021"),xsd:dateTime) as ?when).

You can only parse a variable binding like: bind(strdt(datething:parse(?when_string),xsd:dateTime) as ?when).