1 <html> 2 <head> 3 <title>CL Unification: Function FIND-VARIABLE-VALUE</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: Function FIND-VARIABLE-VALUE</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>Function</i> <strong>FIND-VARIABLE-VALUE</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>Syntax:</h2> 44 45 <p> 46 <pre> 47 <b>find-variable-value</b> <i>variable-name</i> &optional <i>env</i> <i>errorp</i> 48 => <i>value</i>, <i>found</i> 49 </pre> 50 </p> 51 52 <h3>Arguments and Values:</h3> 53 54 <p><i><code>variable-name</code></i>---a <i>symbol</i> denoting a <em>unification variable</em></p> 55 <p><i><code>env</code></i>---an <i>unification-environment</i></p> 56 <p><i><code>value</code></i>---an <i>object</i></p> 57 <p><i><code>found</code></i>---a <i>boolean</i></p> 58 59 60 61 <h2>Description:</h2> 62 63 <p>The function FIND-VARIABLE-VALUE searches the environment 64 <i>env</i> for the <i>value</i> associated to the unification variable 65 <i>variable-name</i>.<p> 66 67 <p>If there is a <i>value</i> associated to <i>variable-name</i> in 68 <i>env</i>, then it is returned; <i>found</i>, the second return 69 value, is T. 70 71 <p>If no value is associated to <i>variable-name</i> then 72 FIND-VARIABLE-NAME signals an error of type 73 UNIFICATION-VARIABLE-UNBOUND if <i>errorp</i> is non-NIL (the 74 default.) If <i>errorp</i> is NIL then FIND-VARIABLE-NAME returns 75 the values NIL and NIL.</p> 76 77 <p><i>env</i> defaults to *NULL-ENVIRONMENT*. 78 79 80 <h2>Affected By:</h2> 81 82 <p>None.</p> 83 84 85 <h2>Exceptional Situations:</h2> 86 87 <p>None.</p> 88 89 90 <h2>See Also:</h2> 91 92 <p>UNIFY:ENVIRONMENT, BINDING, UNIFICATION-VARIABLE-UNBOUND, *NULL-ENVIRONMENT*</p> 93 94 95 <h2>Notes:</h2> 96 97 <p>None.</p> 98 99 </td> 100 101 <!-- <td height="100%"> </td> --> 102 </tr> 103 104 <tr height="100%"> 105 <td height="100%"> </td> 106 <td valign="top" width="80%" height="100%"> 107 108 <div class="content"> 109 <div class="text" style="padding-top: 10px;"> 110 111 <h1>News</h1> 112 113 <p>News in chronological order, most recent on top. 114 </p> 115 116 <ul> 117 <li><strong>2004-10-09</strong><br> 118 Completed description. 119 </li> 120 121 </ul> 122 123 </div> 124 </div> 125 126 </td> 127 128 <td height="100%"> </td> 129 </tr> 130 131 132 133 134 <tr> 135 <td colspan="3" valign="bottom" align="right"> 136 <div class="copyright"> 137 © 2003-2004, Marco Antoniotti, all rights reserved. 138 </div> 139 </td> 140 </tr> 141 142 </table> 143 </body> 144 </html>