built-in predicate
threaded_engine/1
Description
threaded_engine(Engine)
Enumerates, by backtracking, all existing engines. Engine names shall be regarded as opaque terms; users shall not rely on their type.
Note
This predicate requires a backend Prolog compiler providing
compatible multi-threading primitives. The value of the read-only
engines flag is set to supported
when that
is the case.
Modes and number of proofs
threaded_engine(?nonvar) - zero_or_more
Errors
(none)
Examples
% check that the worker_1 engine exists:
| ?- threaded_engine(worker_1).
% write the names of all existing engines:
| ?- forall(
threaded_engine(Engine),
(writeq(Engine), nl)
).