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modules

This example illustrates compilation of Prolog module files as objects. It doesn't require that the Prolgo backend supports modules.

Due to the lack of standardization of Prolog module systems, the module files can only a common subset of Prolog module directives. Consult the "Prolog Integration and Migration Guide" in the Logtalk documentation for details.

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

%versions

Start by compiling and loading the Prolog module files as objects:

logtalk_load(modules(loader)).

Call one of the module exported predicates using message-sending:

test::names.

<!-- paulo carlos helena

true. -->

Same goal as above but the call is made using a meta-predicate imported from other module:

test::test.

<!-- paulo carlos helena

true. -->

Test the compilation of the module export/1 directive; module exported predicates become public predicates:

exports::current_predicate(Pred).

<!-- Pred = p/1. -->

List the properties of the exports public predicate p/1:

%%table
exports::predicate_property(p(_), Prop).

<!-- Prop = public ; Prop = static ; Prop = declared_in(exports) ; Prop = defined_in(exports). -->

Call the module exported/public predicate using message-sending:

%%table
exports::p(N).

<!-- N = 1 ; N = 2 ; N = 3. -->

Test the compilation and use of meta-predicates:

test::names(Names).

<!-- Names == [paulo, carlos, helena]. -->

test::test(Names).

<!-- Names == [paulo, carlos, helena]. -->