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family_alt

This folder contains an alternative implementation of the family example, which in turn is a version of the classical family tree Prolog example.

This alternative solution defines a family/1 parametric object, providing predicates for common family relations like sister/2 and father/2. This parametric object allows concrete families to be plugged-in by defining the basic female, male, and parent relations as multifile predicates parameterized by the family database object. Several family objects can be loaded at the same time. Using a parametric object to query a family extended relations is convenient as the object parameter allows us to make the name of the concrete family easily available to any predicate.

The main advantage of this solution is that it avoids dynamic binding as found in the family example. Moreover, when this version is compiled in optimized mode, the multifile predicate clauses, which act as liking clauses, are inlined. The main downside of this solution is the boilerplate code that must be written (i.e., the multifile predicate definitions).

Print Logtalk, Prolog backend, and kernel versions (if running as a notebook):

%versions

Load the example:

logtalk_load(family_alt(loader)).

Some example queries using the Addams family relations:

%%table
family(addams)::sister(Sister, Sibling).

Some example queries using the Simpsons family relations:

%%table
family(simpsons)::mother(Mother, Child).

Some example queries using the extended Simpsons family relations:

%%table
family(simpsons_extended)::parent(Parent, Child).