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<html><head><title>XLISP address-of</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>address-of</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>function (subr)</nobr></td>
</tr>
<tr valign="top">
<td><nobr>Source:</nobr></td>
<td><nobr> - </nobr></td>
<td width="100%"><nobr>xlmath.c</nobr></td>
</tr>
</tbody></table></p>
<h2>Syntax</h2>
<p><div class="box">
<dl>
<dt>(<b>address-of</b> <i>expr</i>)</dt>
<dd>expr - an expression<br>
returns - the memory address of the expression as an integer</dd>
</dl>
</div></p>
<h2>Description</h2>
<p>The 'address-of' function returns the internal memory address of the
XLISP node that corresponds to 'expr'. The value returned is an integer.</p>
<h2>Examples</h2>
<pre class="example">
(setq var 0) => 0 <font color="#008844">; set up VAR with 0</font>
(address-of var) => 123224
(address-of 'var) => 182638
(peek (address-of var)) => 83951616
(peek (1+ (address-of var))) => 16777216
(peek (+ 2 (address-of var))) => 0 <font color="#008844">; value of VAR</font>
(setq var 14) => 14 <font color="#008844">; change the value to 14</font>
(peek (+ 2 (address-of var))) => 14
(setq var 99) => 99 <font color="#008844">; change the value to 99</font>
(peek (+ 2 (address-of var))) => 99
</pre>
<p>See <a href="addition.htm"> + </a>,
<a href="increment.htm">1+</a>, <a href="peek.htm">peek</a>,
<a href="setq.htm">setq</a>.</p>
<p><div class="box">
<p><b>Nyquist:</b> The '<nobr>address-of</nobr>' function is internally
disabled, but the code still exists. Look out for PEEK_AND_POKE in the
Nyquist source code.</p>
<p><b>Caution:</b> Be careful when modifying the internal state of XLISP.
<nobr>If you</nobr> have modified it, it would be a good idea to exit XLISP
and <nobr>re-enter</nobr> before doing any work you really want to
retain.</p>
</div></p>
<p>See also:</p>
<ul>
<li><nobr>Contents → <a href="../manual/contents.htm#system-functions">System Functions</a></nobr></li>
</ul>
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