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			78 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
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| 		<title>Logtalk control construct: ::/1</title>
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| <a href="../../index.html">contents</a> > <a href="../index.html">reference manual</a> > <a href="../index.html#constructs">control constructs</a>
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| </div>
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| 
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| <h2><code>::/1</code></h2>
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| 
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| 
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| <h4>Description</h4>
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| 
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| <blockquote>
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| <pre>::Predicate
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| 
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| ::(Predicate1, Predicate2, ...)
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| 
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| ::(Predicate1; Predicate2; ...)</pre>
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| <p>
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| 	Send a message to <a class="glossary" title="Go to glossary definition" href="../../glossary.html#self">self</a>. Only used in the body of a predicate definition. The argument should match a public or protected predicate of <a class="glossary" title="Go to glossary definition" href="../../glossary.html#self">self</a>. It may also match a private predicate if the predicate is imported from a category, if used from inside a category, or when using private inheritance. We can also send a set of messages to self. The "<code>,</code>" and "<code>;</code>" in the list have the usual Prolog meaning.
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| </p>
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| </blockquote>
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| 
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| <h4>Template and modes</h4>
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| 
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| <blockquote>
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| <pre>::+messages</pre>
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| </blockquote>
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| 
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| <h4>Errors</h4>
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| 
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| <blockquote>
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| 	<dl>
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| 		<dt>Predicate is a variable:</dt>
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| 			<dd><code>instantiation_error</code></dd>
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| 		<dt>Predicate is declared private:</dt>
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| 			<dd><code>permission_error(access, private_predicate, Predicate)</code></dd>
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| 		<dt>Predicate is not declared:</dt>
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| 			<dd><code>existence_error(predicate_declaration, Predicate)</code></dd>
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| 	</dl>
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| </blockquote>
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| 
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| <h4>Examples</h4>
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| 
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| <blockquote>
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| <pre>area(Area) :-
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|     ::width(Width),
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|     ::height(Height),
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|     Area is Width*Height.</pre>
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| </blockquote>
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| Copyright © <a href="mailto:pmoura@logtalk.org">Paulo Moura</a> — <a href="http://www.logtalk.org">Logtalk.org</a>
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