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<html>
<head><title>CASE.html -- ACL2 Version 3.1</title></head>
<body text=#000000 bgcolor="#FFFFFF">
<h2>CASE</h2>conditional based on if-then-else using <code><a href="EQL.html">eql</a></code>
<pre>Major Section: <a href="PROGRAMMING.html">PROGRAMMING</a>
</pre><p>
<pre>
Example Form:
(case typ
((:character foo)
(open file-name :direction :output))
(bar (open-for-bar file-name))
(otherwise
(my-error "Illegal.")))
</pre>
is the same as
<pre>
(cond ((member typ '(:character foo))
(open file-name :direction :output))
((eql typ 'bar)
(open-for-bar file-name))
(t (my-error "Illegal.")))
</pre>
which in turn is the same as
<pre>
(if (member typ '(:character foo))
(open file-name :direction :output)
(if (eql typ 'bar)
(open-for-bar file-name)
(my-error "Illegal.")))
<p>
</pre>
Notice the quotations that appear in the example above:
<code>'(:character foo)</code> and <code>'bar</code>.<p>
<pre>
General Forms:
(case expr
(x1 val-1)
...
(xk val-k)
(otherwise val-k+1))<p>
(case expr
(x1 val-1)
...
(xk val-k)
(t val-k+1))<p>
(case expr
(x1 val-1)
...
(xk val-k))
</pre>
where each <code>xi</code> is either <code><a href="EQLABLEP.html">eqlablep</a></code> or a true list of <code><a href="EQLABLEP.html">eqlablep</a></code>
objects. The final <code>otherwise</code> or <code>t</code> case is optional.<p>
<code>Case</code> is defined in Common Lisp. See any Common Lisp
documentation for more information.
<br><br><br><a href="acl2-doc.html"><img src="llogo.gif"></a> <a href="acl2-doc-index.html"><img src="index.gif"></a>
</body>
</html>
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