10.4 IMPORTING AND EXPORTING CONSTRUCTS

Unless specifically exported and imported, the constructs of one module may not be used by another module. A construct is said to be visible or within scope of a module if that construct can be used by the module. For example, if module B wants to use the foo deftemplate defined in module A, then module A must export the foo deftemplate and module B must import the foo deftemplate from module A.

CLIPS> (clear)
CLIPS> (defmodule A)
CLIPS> (deftemplate A::foo (slot x))
CLIPS> (defmodule B)
CLIPS> (defrule B::bar (foo (x 3)) =>)
[PRNTUTIL2] Syntax Error:  Check appropriate syntax for defrule
ERROR:
(defrule B::bar
   (foo (
CLIPS> (clear)
CLIPS> (defmodule A (export deftemplate foo))
CLIPS> (deftemplate A::foo (slot x))
CLIPS> (defmodule B (import A deftemplate foo))
CLIPS> (defrule B::bar (foo (x 3)) =>)
CLIPS>

CLIPS will not allow a module or other construct to be defined that causes two constructs with the same name to be visible within the same module.

10.4.1 Exporting Constructs