paxos_on_change/2

Documentation
- Reference manual
- Packages
  - Paxos -- a SWI-Prolog replicating key-value store
    - library(paxos): A Replicated Data Store

Availability::- use_module(library(paxos)).(can be autoloaded)

[det]paxos_on_change(?Term, :Goal)

[det]paxos_on_change(?Key, ?Value, :Goal)

Executes the specified Goal when Key changes. paxos_on_change/2 listens for paxos_changed(Key,Value) notifications for Key, which are emitted as the result of successful paxos_set/3 transactions. When one is received for Key, then Goal is executed in a separate thread of execution.

Term is a compound, identical to that used for paxos_get/1.

Goal

is one of:

a callable atom or term, or
the atom ignore, which causes monitoring for Term to be discontinued.