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get_priority(-Priority)

Get the priority of the currently executing goal.
Priority
A variable.

Description

All goals in ECLiPSe execute under a certain priority. An execution can only be interrupted by the waking of a goal with a higher priority. Priorities are most relevant in data-driven algorithms, to specify that certain goals must do their work before others can meaningfully execute.

Priorities range from 1 (most urgent) to 12 (least urgent). The toplevel goal of an execution always runs at the lowest priority (12).

Warning: Although it is possible to write programs that only work correctly under a particular priority ordering, such practice is strongly discouraged. Priorities should only affect efficiency, never correctness.

Modes and Determinism

Exceptions

(24) number expected
Priority is neither variable nor number.

Examples

    [eclipse 1]: get_priority(P).
    P = 12
    yes.

    [eclipse 2]: [user].
     p :- get_priority(P), writeln(prio=P).

    user       compiled traceable 120 bytes in 0.00 seconds
    yes.
    [eclipse 3]: suspend(p, 5, X->inst), X=1.
    prio = 5
    X = 1
    yes.



See Also

call_priority / 2, make_suspension / 3, make_suspension / 4, suspend / 3, suspend / 4, set_suspension_data / 3