kapps_ogm.utils.errors

Exception types for the kapps_ogm package.

exception kapps_ogm.utils.errors.AnonymousNodeFetchError

Bases: ValueError

Raised when OGM.fetch is called on a Skolem IRI.

Skolem IRIs identify anonymous nodes that have no rdf:type and can only be reached through their parent node. Attempting to fetch them directly would bypass the structural context required to interpret them correctly.

exception kapps_ogm.utils.errors.AmbiguousNodeAlignmentError

Bases: ValueError

Raised when a fetched node’s anonymous values cannot be aligned with the outgoing ones.

Anonymous nodes under one property are aligned positionally, since nothing else distinguishes them. When the outgoing list is shorter than the stored one, there is no way to tell which node was dropped, and guessing would shift a surviving node’s address onto the wrong entry — silently moving one parameter’s properties onto another parameter’s node. That is a worse failure than losing an address, so it is refused.

exception kapps_ogm.utils.errors.UnresolvableNodeAddressError

Bases: ValueError

Raised on the write path when the RDF address of an anonymous node cannot be resolved.

This exception exists so that an unresolvable target can never silently become a freshly minted node, which would orphan every triple the ClassSpec does not declare. It protects referential integrity during serialization and commit operations.