Compact IRIs not supported in RestrictTo clauses

[jindrichmynarz]

It seems that <RestrictTo> doesn't support compact IRIs. When I use a Silk LSL with compact IRIs in <RestrictTo>, having defined their prefixes in <Prefixes> (complete linkage rule), I get this error when executing the linkage rule:

Exception in thread "main" java.lang.IllegalArgumentException: The following prefixes are not defined:  rov:, dcterms:
	at org.silkframework.entity.rdf.SparqlRestriction$.fromSparql(SparqlRestriction.scala:66)
	at org.silkframework.entity.Restriction$.custom(Restriction.scala:51)
	at org.silkframework.entity.Restriction$.parse(Restriction.scala:66)
	at org.silkframework.rule.DatasetSelection$.fromXML(DatasetSelection.scala:86)
	at org.silkframework.rule.LinkSpec$LinkSpecificationFormat$.read(LinkSpec.scala:133)
	at org.silkframework.rule.LinkSpec$LinkSpecificationFormat$.read(LinkSpec.scala:114)
	at org.silkframework.runtime.serialization.XmlSerialization$.fromXml(XmlSerialization.scala:16)
	at org.silkframework.config.Task$TaskFormat.read(Task.scala:61)
	at org.silkframework.config.Task$TaskFormat.read(Task.scala:54)
	at org.silkframework.runtime.serialization.XmlSerialization$.fromXml(XmlSerialization.scala:16)
	at org.silkframework.rule.LinkingConfig$LinkingConfigFormat$$anonfun$6.apply(LinkingConfig.scala:126)
	at org.silkframework.rule.LinkingConfig$LinkingConfigFormat$$anonfun$6.apply(LinkingConfig.scala:126)
	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
	at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:234)
	at scala.collection.Iterator$class.foreach(Iterator.scala:893)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1336)
	at scala.collection.IterableLike$class.foreach(IterableLike.scala:72)
	at scala.collection.AbstractIterable.foreach(Iterable.scala:54)
	at scala.collection.TraversableLike$class.map(TraversableLike.scala:234)
	at scala.collection.AbstractTraversable.map(Traversable.scala:104)
	at org.silkframework.rule.LinkingConfig$LinkingConfigFormat$.readWithPrefixes(LinkingConfig.scala:126)
	at org.silkframework.rule.LinkingConfig$LinkingConfigFormat$.read(LinkingConfig.scala:115)
	at org.silkframework.rule.LinkingConfig$LinkingConfigFormat$.read(LinkingConfig.scala:102)
	at org.silkframework.runtime.serialization.XmlSerialization$.fromXml(XmlSerialization.scala:16)
	at org.silkframework.Silk$.executeFile(Silk.scala:115)
	at org.silkframework.Silk$.execute(Silk.scala:97)
	at org.silkframework.Silk$$anonfun$1.apply$mcV$sp(Silk.scala:218)
	at org.silkframework.util.CollectLogs$.apply(CollectLogs.scala:29)
	at org.silkframework.Silk$.main(Silk.scala:217)
	at org.silkframework.Silk.main(Silk.scala)

It appears that the regular expressions for parsing compact IRIs in SparqlRestriction.scala are too brittle. Perhaps it would be safer to wrap the RestrictTo in SELECT * WHERE { ... } plus the declared prefixes and having it parsed via Jena.

Tested using the latest master version (c7015f6).