1 <html> 2 <head> 3 <title>CL Unification: Class NTHCDR-TEMPLATE</title> 4 <link rel="stylesheet" href="main.css"> 5 </head> 6 7 <body marginheight="0" marginwidth="0" leftmargin="0" topmargin="0" bgcolor="#ffffff"> 8 9 <table border="0" cellpadding="0" cellspacing="0" width="100%" height="100%" vspace="0" hspace="0"> 10 <tr> 11 <td colspan="3"> 12 <div class="header" 13 style="font-family:=Verdana,Arial,Helvetica; font-size: 18px; color: #41286f;"> 14 <strong><i>CL Unification: Class NTHCDR-TEMPLATE</title></i></strong> 15 <div class="navigation"> 16 <a href="index.html" class="navigation-link">Home</a> 17 | <a href="unification-package.html" class="navigation-link">Previous</a> 18 | <a href="index.html" class="navigation-link">Next</a> 19 | <a href="downloads.html" class="navigation-link">Downloads</a> 20 | <a href="links.html" class="navigation-link">Links</a> 21 </div> 22 </div> 23 <div class="black-line"><img src="images/shim.gif" height="1" width="1"></div> 24 <div class="middle-bar"><img src="images/shim.gif" height="5" width="1"></div> 25 <div class="black-line"><img src="images/shim.gif" height="1" width="1"></div> 26 </td> 27 </tr> 28 29 <tr height="100%"> 30 <td height="100%"> </td> 31 <td valign="top" width="80%" height="100%"> 32 33 <div class="content"> 34 <div class="text" style="padding-top: 10px;"> 35 36 <h1><i>Class</i> <strong>NTHCDR-TEMPLATE</strong></h1> 37 38 <h2>Package:</h2> 39 40 <p><code>COMMON-LISP.EXTENSIONS.DATA-AND-CONTROL-FLOW.UNIFICATION</code></p> 41 42 43 <h2>Class Precedence List:</h2> 44 45 <p> 46 NTHCDR-TEMPLATE, ELEMENT-TEMPLATE, EXPRESSION-TEMPLATE, TEMPLATE, STANDARD-OBJECT, T. 47 </p> 48 49 <h2>Known Subclasses:</h2> 50 51 <p> 52 None. 53 </p> 54 55 56 <h2>Slots:</h2> 57 58 <p>None.</p> 59 60 61 <h2>Description:</h2> 62 63 <p>The NTHCDR-TEMPLATE class denotes those object that are used 64 to unify against a particular CONS of a LIST.</p> 65 66 <h3>Template Syntax:</h3> 67 68 <p> 69 <pre> 70 #T(<b>nthcdr</b> <i>index</i> <i>item</i>) 71 </pre> 72 </p> 73 74 <p>The NTHCDR-TEMPLATE syntax denotes the CONS <i>item</i> at <i>index</i> 75 a LIST. A NTHCDR-TEMPLATE must 76 be unified against a LIST object. <i>item</i> is <em>unified</em> 77 against the element extracted from the LIST object at 78 <i>index</i> by the standard function NTHCDR.</p> 79 80 81 <h2>Examples:</h2> 82 83 <p> 84 <pre> 85 cl-prompt> (setf e (unify '(0 1 42 3 4 5) #T(<b>nthcdr</b> 2 ?x))) 86 #<ENVIRONMENT xxx> 87 88 cl-prompt> (find-variable-value '?x e) 89 (42 3 4 5) 90 91 cl-prompt> (setq e (unify '(0 1 42 3 4 5) #T(<b>nthcdr</b> 42 ?x))) 92 --> Error: index 42 out of bounds. <STRONG>FIX THIS</STRONG> 93 94 95 cl-prompt> (setq e (unify #(a s d) #T(<b>nthcdr</b> 1 ?x))) 96 --> Error: UNIFICATION-FAILURE 97 </pre> 98 </p> 99 100 101 <h2>Affected By:</h2> 102 103 <p>None.</p> 104 105 106 <h2>Exceptional Situations:</h2> 107 108 <p>Unifying an NTHCDR-TEMPLATE against a non-LIST object results in 109 an UNIFICATION-FAILURE error being signaled.</p> 110 111 112 <h2>See Also:</h2> 113 114 <p>UNIFY</p> 115 116 <h2>Notes:</h2> 117 118 <p>None.</p> 119 120 </td> 121 122 <!-- <td height="100%"> </td> --> 123 </tr> 124 125 <tr height="100%"> 126 <td height="100%"> </td> 127 <td valign="top" width="80%" height="100%"> 128 129 <div class="content"> 130 <div class="text" style="padding-top: 10px;"> 131 132 <h1>News</h1> 133 134 <p>News in chronological order, most recent on top. 135 </p> 136 137 <ul> 138 <li><strong>2004-06-11</strong><br> 139 Completed description. 140 </li> 141 142 </ul> 143 144 </div> 145 </div> 146 147 </td> 148 149 <td height="100%"> </td> 150 </tr> 151 152 153 154 155 <tr> 156 <td colspan="3" valign="bottom" align="right"> 157 <div class="copyright"> 158 © 2003-2004, Marco Antoniotti, all rights reserved. 159 </div> 160 </td> 161 </tr> 162 163 </table> 164 </body> 165 </html> 166 167 <!-- end of file -- expression-template-class.html -->