git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1903 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
		
			
				
	
	
		
			71 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
			
		
		
	
	
			71 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
| <?xml version="1.0" encoding="utf-8"?>
 | |
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
 | |
|     "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
 | |
| 
 | |
| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
 | |
| 
 | |
| 	<head>
 | |
| 	<meta http-equiv="content-type" content="application/xml+xhtml; charset=utf-8" />
 | |
| 		<title>Logtalk control construct: ::/1</title>
 | |
| 		<link rel="stylesheet" href="../../screen.css" type="text/css" media="screen"/>
 | |
| 	<link rel="stylesheet" href="../../print.css" type="text/css" media="print"/>
 | |
| 	</head>
 | |
| 
 | |
| <body>
 | |
| 
 | |
| <div class="top-left">Logtalk reference manual</div> 
 | |
| <div class="top-right">Control construct: ::/1</div>
 | |
| <div class="bottom-left"><span class="page"/></div> 
 | |
| <div class="bottom-right"><span class="page"/></div>
 | |
| <div class="navtop"><a href="../../index.html">contents</a> > <a href="../index.html">reference manual</a> > <a href="../index.html#constructs">control constructs</a></div>
 | |
| 
 | |
| <h2 id="control_to_self1" class="codenp">::/1</h2>
 | |
| 
 | |
| <h4>Description</h4>
 | |
| 
 | |
| <pre>::Predicate
 | |
| 
 | |
| ::(Predicate1, Predicate2, ...)
 | |
| 
 | |
| ::(Predicate1; Predicate2; ...)</pre>
 | |
| <p>
 | |
| 	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 within the scope of the object where the method making the call is defined, if 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.
 | |
| </p>
 | |
| 
 | |
| <h4>Template and modes</h4>
 | |
| 
 | |
| <pre>::+messages</pre>
 | |
| 
 | |
| <h4>Errors</h4>
 | |
| 
 | |
| <dl>
 | |
| 	<dt>Predicate is a variable:</dt>
 | |
| 		<dd><code>instantiation_error</code></dd>
 | |
| 	<dt>Predicate is declared private:</dt>
 | |
| 		<dd><code>permission_error(access, private_predicate, Predicate)</code></dd>
 | |
| 	<dt>Predicate is not declared:</dt>
 | |
| 		<dd><code>existence_error(predicate_declaration, Predicate)</code></dd>
 | |
| </dl>
 | |
| 
 | |
| <h4>Examples</h4>
 | |
| 
 | |
| <pre>area(Area) :-
 | |
|     ::width(Width),
 | |
|     ::height(Height),
 | |
|     Area is Width*Height.</pre>
 | |
| 
 | |
| <div class="footer">
 | |
| 	<div class="copyright">
 | |
| 		<span>Copyright © <a href="mailto:pmoura@logtalk.org">Paulo Moura</a> — <a href="http://logtalk.org">Logtalk.org</a></span><br/>	
 | |
| 		<span>Last updated on: October 26, 2006</span>
 | |
| 	</div>
 | |
| 	<div class="navbottom">
 | |
| 		<span><a href="to_object2.html">previous</a> | <a href="../../glossary.html">glossary</a> | <a href="to_super1.html">next</a></span><br/>
 | |
| 		<span><a href="http://validator.w3.org/check/referer">XHTML</a> + <a href="http://jigsaw.w3.org/css-validator/check/referer">CSS</a></span>
 | |
| 	</div>
 | |
| </div>
 | |
| 
 | |
| </body>
 | |
| 
 | |
| </html>
 |