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<html><head><title>XLISP function</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>function</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>
<dl>
<dt>(function <i>expr</i>)</dt>
<dd><i>expr</i> - an expression that evaluates to a function<br>
returns - the functional interpretation</dd>
</dl>
<h2>Description</h2>
<p>The 'function' special form returns the function definition of the
'expr'. Execution of the 'expr' form does not occur. 'function' will operate
on functions, special forms, lambda-expressions and macros.</p>
<h2>Examples</h2>
<pre class="example">
(function car) <font color="#008844">; returns #<Subr-CAR: #23ac4></font>
(function quote) <font color="#008844">; returns #<FSubr-QUOTE: #23d1c></font>
#'quote <font color="#008844">; returns #<FSubr-QUOTE: #23d1c></font>
(function 'cdr) <font color="#008844">; error: not a function</font>
(defun foo (x) (+ x x)) <font color="#008844">; define FOO function</font>
(function foo) <font color="#008844">; returns #<Closure-FOO: #2cfb6></font>
(defmacro bar (x) (+ x x)) <font color="#008844">; define FOOMAC macro</font>
(function bar) <font color="#008844">; returns #<Closure-BAR: #2ceee></font>
(setq my 99) <font color="#008844">; define a variable MY</font>
(function my) <font color="#008844">; error: unbound function</font>
(defun my (x) (print x)) <font color="#008844">; define a function MY</font>
(function my) <font color="#008844">; returns #<Closure-MY: #2cdd6></font>
</pre>
<p><b>Read macro:</b> XLISP supports the normal Lisp read macro of a hash
and quote [#'] as a short-hand method of writing the 'function' special
form.</p>
<p>See the
<a href="../manual/xlisp-man-012.htm#function">function</a>
special form in the <nobr>XLISP 2.0</nobr> manual.</p>
<p><nobr> <a href="#top">Back to Top</nobr></a></p>
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