[ Obsolete | Reference Manual | Alphabetic Index ]

call(+Goal, +Module)

Succeeds if Goal (which is visible in module Module) succeeds.

Goal: Atom or compound term.
Module: Atom.

This built-in predicate is obsolete!

Description

Calls a goal Goal from the module Module. This predicate is used to call goals whose functors and visibility are known only at the time they are called. It may be used to implement tool bodies.

Note that !/0 does not cut through call/2.

Fail Conditions

Fails if Goal fails

Resatisfiable

Resatisfiable if Goal is resatisfiable

Exceptions

(4) instantiation fault: Goal is not instantiated.
(4) instantiation fault: Module is not instantiated.
(5) type error: Goal is neither an atom nor a compound term.
(5) type error: Module is not an atom.
(68) calling an undefined procedure: Goal is an undefined procedure in Module.

Examples

Success:
      [eclipse]: [user].
       :-module(m).
       p.
       user        compiled 28 bytes in 0.00 seconds
      yes.
      [eclipse]: p.
      calling an undefined procedure p in module eclipse
      [eclipse]: call(p, m).
      yes.

Fail: call(fail, any).

Error:
      call(Var,eclipse).                (Error 4).
      call(ls,Var).                     (Error 4).
      call("write(a)",eclipse).         (Error 5).
      call(foo(a),eclipse).             (Error 68).