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<title>Logtalk built-in predicate: extends_object/2-3</title>
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<div class="top-left">Logtalk reference manual</div>
<div class="top-right">Built-in predicate: extends_object/2-3</div>
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<h2 class="codenp">extends_object/2-3<span id="builtins_extends_object2_3"/></h2>
<h4>Description</h4>
<pre>extends_object(Prototype, Parent)
extends_object(Prototype, Parent, Scope)</pre>
<p>
Enumerates, by backtracking, all pairs of objects such that the first one extends the second. The relation scope is represented by the atoms <code>public</code>, <code>protected</code>, and <code>private</code>.
</p>
<h4>Template and modes</h4>
<pre>extends_object(?object_identifier, ?object_identifier)
extends_object(?object_identifier, ?object_identifier, ?scope)</pre>
<h4>Errors</h4>
<dl>
<dt>Prototype is neither a variable nor a valid object identifier:</dt>
<dd><code>type_error(object_identifier, Prototype)</code></dd>
<dt>Parent is neither a variable nor a valid object identifier:</dt>
<dd><code>type_error(object_identifier, Parent)</code></dd>
<dt>Scope is neither a variable nor a valid entity scope:</dt>
<dd><code>type_error(scope, Scope)</code></dd>
</dl>
<h4>Examples</h4>
<pre>| ?- extends_object(Object, state_space).
| ?- extends_object(Object, list, public).</pre>
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<span>Last updated on: October 26, 2006</span>
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