/usr/lib/swi-prolog/doc/Manual/overrule.html

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<H2><A NAME="sec:5.5"><SPAN class="sec-nr">5.5</SPAN> <SPAN class="sec-title">Overruling 
Module Boundaries</SPAN></A></H2>

<A NAME="sec:overrule"></A>

<P>The module system described so far is sufficient to distribute 
programs over multiple modules. There are however cases in which we 
would like to be able to overrule this schema and explicitly call a 
predicate in some module or assert explicitly into some module. Calling 
in a particular module is useful for debugging from the user's top-level 
or to access multiple implementations of the same interface that reside 
in multiple modules. Accessing the same interface from multiple modules 
cannot be achieved using importing because importing a predicate with 
the same name and arity from two modules results in a name conflict. 
Asserting in a different module can be used to create models dynamically 
in a new module. See <A class="sec" href="dynamic-modules.html">section 
5.12</A>.

<P>Direct addressing of modules is achieved using a <CODE><CODE>:</CODE>/2</CODE> 
explicitly in a program and rely on the module qualification mechanism 
described in <A class="sec" href="metapred.html">section 5.4</A>. Here 
are a few examples:

<PRE class="code">
?- assert(world:done).  % asserts done/0 into module world
?- world:assert(done).  % the same
?- world:done.          % calls done/0 in module world
</PRE>

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swi-prolog-nox 5.10.4-3ubuntu1 / usr / lib / swi-prolog / doc / Manual / overrule.html
