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<html><head><title>XLISP block</title>
<link rel="stylesheet" type="text/css" href="reference.css">
</head>
<body>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
<hr>
<h1>block</h1>
<hr>
<p><table cellpadding="0" cellspacing="0" style="margin-left:10px"><tbody>
<tr valign="top">
<td><nobr>Type:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>special form (fsubr)</nobr></td>
</tr>
<tr valign="top">
<td><nobr>Source:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>xlcont.c</nobr></td>
</tr>
</tbody></table></p>
<h2>Syntax</h2>
<p><div class="box">
<dl>
<dt><b>(block</b> <i>name</i> [<i>body</i> ... ])</dt>
<dd><i>name</i> - an unevaluated symbol for the block name<br>
<i>body</i> - an arbitrary number of Lisp expressions<br>
returns - the value of the last expression</dd>
</dl>
</div></p>
<h2>Description</h2>
<p>The 'block' special form specifies a '<nobr>named block</nobr>'
construct. <nobr>The last</nobr> expression in 'body' will be returned by
the 'block' construct as its result unless a <a href="return.htm">return</a>
or <a href="return-from.htm">return-from</a> is executed within 'block'.
<nobr>The <a href="return.htm">return</a></nobr> exit will exit the nearest
<nobr>[inner-most]</nobr> 'block'.
<nobr>The <a href="return-from.htm">return-from</a></nobr> exit will exit
the specified 'block'.</p>
<h2>Examples</h2>
<pre class="example">
(defun test ()
(block outer <font color="#008844">; outer BLOCK</font>
(print "outer")
(block inner <font color="#008844">; inner BLOCK</font>
(print "inner")
(return-from outer "all done")
(print "won't get here"))))
> (test)
"outer" <font color="#008844">; screen output of PRINT</font>
"inner" <font color="#008844">; screen output of PRINT</font>
"all done" <font color="#008844">; return value</font>
</pre>
<p>See <a href="defun.htm">defun</a>, <a href="print.htm">print</a>,
<nobr><a href="return-from.htm">return-from</a></nobr>.</p>
<p>See also:</p>
<ul>
<li><nobr>Contents → <a href="../manual/contents.htm#control-constructs">Control Constructs</a></nobr></li>
</ul>
<p><nobr> <a href="#top">Back to Top</nobr></a></p>
<hr>
<a href="../start.htm">Nyquist / XLISP 2.0</a> -
<a href="../manual/contents.htm">Contents</a> |
<a href="../tutorials/tutorials.htm">Tutorials</a> |
<a href="../examples/examples.htm">Examples</a> |
<a href="reference-index.htm">Reference</a>
</body></html>
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