chunk(+Count)

Modify the chunk-size to Count before asking the next set of solutions.

Remaining options are passed to pengine_send/3. The result of re-executing the current goal is returned to the caller's message queue in the form of event terms.

success(ID, Terms, More)

ID is the id of the pengine that succeeded in finding yet another solution to the query. Terms is a list holding instantiations of Template. More is either true or false, indicating whether we can expect the pengine to be able to return more solutions or not, would we call pengine_next/2.

failure(ID)

ID is the id of the pengine that failed for lack of more solutions.

error(ID, Term)

ID is the id of the pengine throwing the exception. Term is the exception's error term.

output(ID, Term)

ID is the id of a pengine running the query that called pengine_output/1. Term is the term that was passed in the first argument of pengine_output/1 when it was called.

prompt(ID, Term)

ID is the id of the pengine that called pengine_input/2 and Term is the prompt.

Defined in terms of pengine_send/3, as follows:

pengine_next(ID, Options) :-
    pengine_send(ID, next, Options).