threaded_engine_next/2¶
Description¶
threaded_engine_next(Engine, Answer)
Retrieves the next answer from an engine. This predicate blocks until an answer becomes available. The predicate fails when there are no more solutions to the engine goal. If the engine goal throws an exception, calling this predicate will re-throw the exception and subsequent calls will fail.
Modes and number of proofs¶
threaded_engine_next(@nonvar, ?term) - zero_or_one
Errors¶
Engine is a variable:
instantiation_error
Engine is neither a variable nor the name of an existing engine:
existence_error(engine, Engine)
Examples¶
% get the next answer from the worker_1 engine:
| ?- threaded_engine_next(worker_1, Answer).