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<p><strong>readtablep</strong> <span><i>Function</i></span></p>
<p><strong>Syntax:</strong></p>
<p><span><b>readtablep</b></span> <em>object → generalized-boolean</em></p>
<p><strong>Arguments and Values:</strong></p>
<p><span><i>object</i></span>—an <span><i>object</i></span>.</p>
<p><em>generalized-boolean</em>—a <span><i>generalized boolean</i></span>.</p>
<p><strong>Description:</strong></p>
<p>Returns <span><i>true</i></span> if <span><i>object</i></span> is of <span><i>type</i></span> <span><b>readtable</b></span>; otherwise, returns <span><i>false</i></span>.</p>
<p><strong>Examples:</strong></p>
<div class="language-lisp codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-lisp codeBlock_bY9V thin-scrollbar" style="color:#393A34;background-color:#f6f8fa"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token plain"> </span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">readtablep</span><span class="token plain"> \*readtable\*</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> → true </span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">readtablep</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">copy-readtable</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> → true </span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"></span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">readtablep</span><span class="token plain"> \*readtable\*</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> → false </span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg viewBox="0 0 24 24" class="copyButtonIcon_y97N"><path fill="currentColor" d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg viewBox="0 0 24 24" class="copyButtonSuccessIcon_LjdS"><path fill="currentColor" d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div>
<p><strong>Notes:</strong></p>
<p>(readtablep <span><i>object</i></span>) <em></em> (typep <span><i>object</i></span> readtable)</p>
<p><strong>set-dispatch-macro-character,</strong> <em>. . .</em></p>
<b><sup>set-dispatch-macro-character, get-dispatch-macro</sup> character</b>
<i>Function</i>
<p><strong>Syntax:</strong></p>
<p><strong>get-dispatch-macro-character</strong> <em>disp-char sub-char</em> &amp;optional <em>readtable → function</em></p>
<p><strong>set-dispatch-macro-character</strong> <em>disp-char sub-char new-function</em> &amp;optional <em>readtable →</em> <span><b>t</b></span></p>
<p><strong>Arguments and Values:</strong></p>
<p><em>disp-char</em>—a <span><i>character</i></span> .</p>
<p><em>sub-char</em>—a <span><i>character</i></span> .</p>
<p><span><i>readtable</i></span>—a <span><i>readtable designator</i></span> . The default is the <span><i>current readtable</i></span>.</p>
<p><span><i>function</i></span>—a <span><i>function designator</i></span> or <span><b>nil</b></span>.</p>
<p><em>new-function</em>—a <span><i>function designator</i></span> .</p>
<p><strong>Description:</strong></p>
<p><strong>set-dispatch-macro-character</strong> causes <em>new-function</em> to be called when <em>disp-char</em> followed by <em>sub-char</em> is read. If <em>sub-char</em> is a lowercase letter, it is converted to its uppercase equivalent. It is an error if <em>sub-char</em> is one of the ten decimal digits.</p>
<p><strong>set-dispatch-macro-character</strong> installs a <em>new-function</em> to be called when a particular <span><i>dispatching macro character</i></span> pair is read. <em>New-function</em> is installed as the dispatch function to be called when <span><i>readtable</i></span> is in use and when <em>disp-char</em> is followed by <em>sub-char</em>.</p>
<p>For more information about how the <em>new-function</em> is invoked, see Section 2.1.4.4 (Macro Characters).</p>
<p><strong>get-dispatch-macro-character</strong> retrieves the dispatch function associated with <em>disp-char</em> and <em>sub-char</em> in <span><i>readtable</i></span>.</p>
<p><strong>get-dispatch-macro-character</strong> returns the macro-character function for <em>sub-char</em> under <em>disp char</em>, or <span><b>nil</b></span> if there is no function associated with <em>sub-char</em>. If <em>sub-char</em> is a decimal digit, <strong>get-dispatch-macro-character</strong> returns <span><b>nil</b></span>.</p>
<p><strong>Examples:</strong></p>
<div class="language-lisp codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#393A34;--prism-background-color:#f6f8fa"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-lisp codeBlock_bY9V thin-scrollbar" style="color:#393A34;background-color:#f6f8fa"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#393A34"><span class="token punctuation" style="color:#393A34">(</span><span class="token car">get-dispatch-macro-character</span><span class="token plain"> #\# #\\&amp;#123</span><span class="token comment" style="color:#999988;font-style:italic">;) → NIL </span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">set-dispatch-macro-character</span><span class="token plain"> #\# #\\&amp;#123</span><span class="token comment" style="color:#999988;font-style:italic">; ;dispatch on #\&amp;#123; </span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> #</span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">lambda</span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">s</span><span class="token plain"> c n</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">let</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">list</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">read</span><span class="token plain"> s </span><span class="token boolean" style="color:#36acaa">nil</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">values</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token boolean" style="color:#36acaa">t</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">)</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">;list is object after #n\&amp;#123; </span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">when</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">consp</span><span class="token plain"> list</span><span class="token punctuation" style="color:#393A34">)</span><span class="token plain"> </span><span class="token comment" style="color:#999988;font-style:italic">;return nth element of list </span><span class="token plain"></span><br></span><span class="token-line" style="color:#393A34"><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">unless</span><span class="token plain"> </span><span class="token punctuation" style="color:#393A34">(</span><span class="token keyword" style="color:#00009f">and</span><span class="token plain"> n </span><span class="token punctuation" style="color:#393A34">(</span><span class="token car">&lt;</span><span class="token plain"> </span><span class="token number" style="color:#36acaa">0</span><span class="token plain"> n </span><span class="token punctuatio
<p><strong>See Also:</strong></p>
<p>Section 2.1.4.4 (Macro Characters)</p>
<p><strong>Side Effects:</strong></p>
<p>The <span><i>readtable</i></span> is modified.</p>
<p><strong>Affected By:</strong></p>
<p><span><b>*readtable*</b></span>.</p>
<p><strong>Exceptional Situations:</strong></p>
<p>For either function, an error is signaled if <em>disp-char</em> is not a <span><i>dispatching macro character</i></span> in <span><i>readtable</i></span>.</p>
<p><strong>See Also:</strong></p>
<span><b>*readtable*</b></span>
<p><strong>Notes:</strong></p>
<p>It is necessary to use <span><b>make-dispatch-macro-character</b></span> to set up the dispatch character before specifying its sub-characters.</p>
<h2 class="anchor anchorWithStickyNavbar_LWe7" id="expanded-reference-readtablep">Expanded Reference: readtablep<a href="readtablep_function.html#expanded-reference-readtablep" class="hash-link" aria-label="Direct link to Expanded Reference: readtablep" title="Direct link to Expanded Reference: readtablep"></a></h2>
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