The path access type for objects if they carry a temporal trace.
The path access type for objects if they carry a temporal trace. This is
used by confluently persistent systems, while it is typically Unit for
ephemeral systems.
The identifier type of the system.
The identifier type of the system. This is an opaque type about which the user only knows that it uniquely identifies and object (or an object along with its access path in the confluent case). It is thus valid to assume that two objects are equal if their identifiers are equal.
The transaction type of the system.
The transaction type of the system.
The variable type of the system.
The variable type of the system. Variables allow transactional storage and
retrieval both of immutable and mutable values. Specific systems may extend
the minimum capabilities described by the Var trait.
Closes the underlying database (if the system is durable).
Closes the underlying database (if the system is durable). The STM cannot be used beyond this call. An in-memory system should have a no-op implementation.
Reports the current number of records stored in the database.
Reports the current number of records stored in the database.
Reports the current number of user records stored in the database.
Reports the current number of user records stored in the database. That is the number of records minus those records used for database maintenance.
Reads the root object representing the stored data structure,
or provides a newly initialized one via the init argument,
if no root has been stored yet.
Reads the root object representing the stored data structure,
or provides a newly initialized one via the init argument,
if no root has been stored yet.