Package datomic

Interface Datom


  • public interface Datom
    An immmutable, point-in-time fact: [entity, attribute, value, transaction, added]
    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      java.lang.Object a()
      This datom's attribute id.
      boolean added()
      Is this datom added or retracted?
      java.lang.Object e()
      This datom's entity id.
      java.lang.Object get​(int index)
      Positional getter, as if datom is tuple of [e a v tx added]
      java.lang.Object tx()
      This datom's transaction id.
      java.lang.Object v()
      This datom's value.
    • Method Detail

      • e

        java.lang.Object e()
        This datom's entity id.
        Returns:
        entity id
      • a

        java.lang.Object a()
        This datom's attribute id.
        Returns:
        attribute id
      • v

        java.lang.Object v()
        This datom's value.
        Returns:
        value
      • tx

        java.lang.Object tx()
        This datom's transaction id.
        Returns:
        transaction id
      • added

        boolean added()

        Is this datom added or retracted?

        When datoms come from Database.history(), this method can be used to distinguish additions from retractions
        Returns:
        a boolean indicating whether this datom was added or retracted
      • get

        java.lang.Object get​(int index)
        Positional getter, as if datom is tuple of [e a v tx added]
        Parameters:
        index - numeric index in the range [0,4]
        Returns:
        the value at this position in the datom