================================================================= Logtalk - Object oriented extension to Prolog Release 2.22.1 Copyright (c) 1998-2004 Paulo Moura. All Rights Reserved. ================================================================= To load this example and for sample queries, please see the SCRIPT file. This example shows the use of metapredicates in Logtalk. Metapredicates are predicates whose head contains arguments that will be called as goals in the body of the predicate definition. This example defines two objects: sort(_) this is a parametric object containing a method that implements the quicksort sorting algorithm; the parameter is interpreted as the type of the elements being sorted tracer this object implements a metapredicate that is used by sort(_) to trace the sorting algorithm steps