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

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<h1 id="sec:modules"><a id="sec:5"><span class="sec-nr">5</span> <span class="sec-title">Modules</span></a></h1>

<a id="sec:modules"></a>

<p>A Prolog module is a collection of predicates which defines a public 
interface by means of a set of provided predicates and operators. Prolog 
modules are defined by an ISO standard. Unfortunately, the standard is 
considered a failure and, as far as we are aware, not implemented by any 
concrete Prolog implementation. The SWI-Prolog module system syntax is 
derived from the Quintus Prolog module system. The Quintus module system 
has been the starting point for the module systems of a number of 
mainstream Prolog systems, such as SICStus, Ciao and YAP. The underlying 
primitives of the SWI-Prolog module system differ from the mentioned 
systems. These primitives allow for multiple modules in a file, 
hierarchical modules, emulation of other modules interfaces, etc.

<p>This chapter motivates and describes the SWI-Prolog module system. 
Novices can start using the module system after reading
<a class="sec" href="defmodule.html">section 5.2</a> and <a class="sec" href="import.html">section 
5.3</a>. The primitives defined in these sections suffice for basic 
usage until one needs to export predicates that call or manage other 
predicates dynamically (e.g., use <a id="idx:call1:1393"></a><a class="pred" href="metacall.html#call/1">call/1</a>,
<a id="idx:assert1:1394"></a><a class="pred" href="db.html#assert/1">assert/1</a>, 
etc.). Such predicates are called <em>meta predicates</em> and are 
discussed in <a class="sec" href="metapred.html">section 5.4</a>. <a class="sec" href="overrule.html">Section 
5.5</a> to <a class="sec" href="moduleop.html">section 5.8</a> describe 
more advanced issues. Starting with <a class="sec" href="importmodule.html">section 
5.9</a>, we discuss more low-level aspects of the SWI-Prolog module 
system that are used to implement the visible module system, and can be 
used to build other code reuse mechanisms.

<p>
<hr>
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<h2>Section Index</h2>

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<hr>
<div class="toc">
<div class="toc-h2"><a class="sec" href="whymodules.html"><span class="sec-nr">5.1</span> <span class="sec-title">Why 
Use Modules?</span></a></div>
<div class="toc-h2"><a class="sec" href="defmodule.html"><span class="sec-nr">5.2</span> <span class="sec-title">Defining 
a Module</span></a></div>
<div class="toc-h2"><a class="sec" href="import.html"><span class="sec-nr">5.3</span> <span class="sec-title">Importing 
Predicates into a Module</span></a></div>
<div class="toc-h2"><a class="sec" href="metapred.html"><span class="sec-nr">5.4</span> <span class="sec-title">Defining 
a meta-predicate</span></a></div>
<div class="toc-h2"><a class="sec" href="overrule.html"><span class="sec-nr">5.5</span> <span class="sec-title">Overruling 
Module Boundaries</span></a></div>
<div class="toc-h3"><a class="sec" href="overrule.html#sec:5.5.1"><span class="sec-nr">5.5.1</span> <span class="sec-title">Explicit 
manipulation of the calling context</span></a></div>
<div class="toc-h2"><a class="sec" href="mtoplevel.html"><span class="sec-nr">5.6</span> <span class="sec-title">Interacting 
with modules from the top level</span></a></div>
<div class="toc-h2"><a class="sec" href="reexport.html"><span class="sec-nr">5.7</span> <span class="sec-title">Composing 
modules from other modules</span></a></div>
<div class="toc-h2"><a class="sec" href="moduleop.html"><span class="sec-nr">5.8</span> <span class="sec-title">Operators 
and modules</span></a></div>
<div class="toc-h2"><a class="sec" href="importmodule.html"><span class="sec-nr">5.9</span> <span class="sec-title">Dynamic 
importing using import modules</span></a></div>
<div class="toc-h2"><a class="sec" href="resmodules.html"><span class="sec-nr">5.10</span> <span class="sec-title">Reserved 
Modules and using the `user' module</span></a></div>
<div class="toc-h2"><a class="sec" href="altmoduleapi.html"><span class="sec-nr">5.11</span> <span class="sec-title">An 
alternative import/export interface</span></a></div>
<div class="toc-h2"><a class="sec" href="dynamic-modules.html"><span class="sec-nr">5.12</span> <span class="sec-title">Dynamic 
Modules</span></a></div>
<div class="toc-h2"><a class="sec" href="ctxmodule.html"><span class="sec-nr">5.13</span> <span class="sec-title">Transparent 
predicates: definition and context module</span></a></div>
<div class="toc-h2"><a class="sec" href="manipmodule.html"><span class="sec-nr">5.14</span> <span class="sec-title">Module 
properties</span></a></div>
<div class="toc-h2"><a class="sec" href="modulecompat.html"><span class="sec-nr">5.15</span> <span class="sec-title">Compatibility 
of the Module System</span></a></div>
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swi-prolog-nox 6.6.4-2ubuntu1 / usr / lib / swi-prolog / doc / Manual / modules.html
