@spec assert_fact(atom(), [term()]) :: {atom(), [term()]}

Asserts a runtime fact to be added to the next materialization.

In v0.1.0 this is a convenience that returns the fact tuple for use with Logistiki.Knowledge.KnowledgeBase. Persisted knowledge facts are a future concern (the knowledge_facts table is ready for that).

Arguments

• predicate — atom() — the relation name (e.g. :event_type).
• arguments — [term()] — the fact arguments (e.g. [:evt, :deposit_received]).

Returns

• {atom(), [term()]} — the fact tuple.

Examples

iex> Logistiki.Knowledge.assert_fact(:event_type, [:evt, :deposit_received])
{:event_type, [:evt, :deposit_received]}

@spec evaluate(
  Logistiki.Event.Normalized.t(),
  keyword()
) :: {:ok, Logistiki.Knowledge.Result.t()} | {:error, term()}

Evaluates the knowledge program for normalized_event.

Generates runtime facts, materializes the Datalog program, and interprets the result into a %Logistiki.Knowledge.Result{}.

Arguments

• normalized_event — %Logistiki.Event.Normalized{}.
• opts — keyword() — passed through to ExDatalog.materialize/2 (e.g. storage: ExDatalog.Storage.ETS).

Returns

• {:ok, %Logistiki.Knowledge.Result{}} — the evaluation succeeded.
• {:error, term()} — materialization failed.

Examples

iex> {:ok, result} = Logistiki.Knowledge.evaluate(normalized_event)
iex> result.policy
:cash_deposit
iex> result.account_roles[:cash_account]
"ASSETS:CASH:USD:NOSTRO"

@spec load_program() :: module()

Returns the configured knowledge program module.

Returns

• module() — defaults to Logistiki.Knowledge.Program. Override via config :logistiki, :knowledge_program, MyCustomProgram.

Examples

iex> Logistiki.Knowledge.load_program()
Logistiki.Knowledge.Program

@spec materialize(
  Logistiki.Event.Normalized.t(),
  keyword()
) :: {:ok, ExDatalog.Knowledge.t()} | {:error, term()}

Materializes the program and returns raw ExDatalog.Knowledge.

Useful for debugging and testing — the raw knowledge lets you inspect all derived facts directly.

Arguments

• normalized_event — %Logistiki.Event.Normalized{}.
• opts — keyword() — passed through to ExDatalog.materialize/2.

Returns

• {:ok, %ExDatalog.Knowledge{}} — the materialized knowledge.
• {:error, term()} — materialization failed.

Examples

iex> {:ok, knowledge} = Logistiki.Knowledge.materialize(normalized_event)
iex> ExDatalog.Knowledge.get(knowledge, "policy")
MapSet.new({:evt, :cash_deposit})

@spec rule_categories() :: keyword()

Returns the rule categories used by Logistiki.

Returns

• keyword() — see Logistiki.Knowledge.Rules.categories/0.

Examples

iex> Logistiki.Knowledge.rule_categories()
[
  business_rules: "Datalog-backed: should the event be processed / blocked / approved?",
  ...
]