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current_predicate(?PredSpec)

Succeeds if PredSpec is a visible predicate defined by the user, or a visible library predicate.

PredSpec: Expression of the form Atom/Integer or variable.

Description

Used to check that PredSpec is a user or library predicate visible from the context module, or else to return on backtracking all the current visible predicates.

Modes and Determinism

current_predicate(++) is semidet
current_predicate(-) is multi

Modules

This predicate is sensitive to its module context (tool predicate, see @/2).

Fail Conditions

Fails if PredSpec is not a visible (user or library) predicate

Exceptions

(5) type error: PredSpec is instantiated, but not to the form Atom/Integer.

Examples

Success:
     [eclipse]: current_predicate(X/Y).
     X = intersection
     Y = 3     More? (;)
     yes.
     [eclipse]: current_predicate(X).
     X = (^) / 2     More? (;)
     X = intersection / 3     More? (;)
     X = subtract / 3     More? (;)
     X = append / 3     More? (;)
     yes.

     [eclipse]: [user].
      p.
      user compiled 28 bytes in 0.00 seconds
     yes.
     [eclipse]: current_predicate(p/0).
     yes.
Fail:
     current_predicate(assert/1).
Error:
     current_predicate(a/a).         (Error 5).