it.unibz.inf.ontop.iq.type

Interface UniqueTermTypeExtractor

All Known Implementing Classes:

BasicUniqueTermTypeExtractor

public interface UniqueTermTypeExtractor

To be used ONLY for extracting unique term types. Term types of variables are normally unique in SQL queries (due to strong typing enforced by RDBMS) but NOT in SPARQL queries (dynamic typing). Accessible through Guice (recommended) or through CoreSingletons.

Method Summary

Modifier and Type	Method and Description
Optional<TermType>	extractUniqueTermType(ImmutableTerm term, IQTree subTree) Is expecting the term type to be unique.

Method Detail

extractUniqueTermType

Optional<TermType> extractUniqueTermType(ImmutableTerm term,
                                         IQTree subTree)
                                  throws NonUniqueTermTypeException

Is expecting the term type to be unique. If multiple types are detected in an UNION or a CONSTRUCTION node, throws a NonUniqueTermTypeException. For data nodes and joins, multiple term types due to multiple occurrences of a VARIABLE is not a problem --> the filter condition will fail (as STRICT equality is required). Any type can be therefore returned. DO NOT use it when you don't have such a uniqueness guarantee (-> NonUniqueTermTypeException is interpreted as an internal bug)

Throws:

NonUniqueTermTypeException