Module com.darkcollective.relix.provenance
Package com.darkcollective.relix.provenance

Interface SemiringLibrary

All Known Implementing Classes:
BuiltinSemiringLibrary
public interface SemiringLibrary
A provider of semirings — the extension point through which an annotation algebra the engine has never heard of becomes something a query can ask for by name.

Implementations are discovered with ServiceLoader, so a library is declared both in a module-info provides clause and in a META-INF/services file: a module path reads the first and a class path the second, and a provider missing either is invisible in one of the two packagings without failing anything a compiler can see.

What a semiring has to supply

Four operations and, if the annotation depends on the data, Semiring.base(com.darkcollective.relix.provenance.BaseTuple). Everything the engine does with an annotation is expressed in those five, which is what makes an installed semiring the equal of a built-in one: weighted transitive closure, the positive operators and the provenance surfacing path all go through exactly this interface and recognise nothing by name.
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    name()
    A short identifier for this library, used in diagnostics — including the one that reports two libraries offering the same semiring name.
    default int
    priority()
    Which library wins when two offer a semiring of the same name: the higher priority.
    List<NamedSemiring>
    semirings()
    The semirings this library offers.

  • Method Details

    • name

      String name()
      A short identifier for this library, used in diagnostics — including the one that reports two libraries offering the same semiring name.
      Returns:
      the library's name; never null or blank

    • priority

      default int priority()
      Which library wins when two offer a semiring of the same name: the higher priority.

      The bundled library ships at 0, so a library declaring a higher priority replaces built-in semirings it re-declares, and one declaring a lower priority fills gaps without disturbing them. Either way the engine reports the clash rather than resolving it silently.

      Ties are broken by discovery order, which is not something to rely on: two libraries that both want to own a name should differ in priority.

      Returns:
      this library's priority; higher wins

    • semirings

      List<NamedSemiring> semirings()
      The semirings this library offers.
      Returns:
      the semirings, each with the names it answers to; never null