<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On 24 Jul 2015, at 14:33, Alejandro Zamora Fonseca <<a href="mailto:terefv@ltu.sld.cu" class="">terefv@ltu.sld.cu</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">Hi!<br class=""><br class="">Just now playing a little with ABCL(1.3.2), I saw some strange behaviour:<br class=""><br class="">CL-USER> '(2 . 5)<br class="">(2 . 5)<br class="">CL-USER> '(2 . 5 . 5)<br class="">(2 . 5)<br class="">CL-USER> (equal '(2 . 5) '(2 . 5 . 5))<br class="">T<br class=""><br class="">while other implementations give me an error when i type '(2 . 5 . 5)<br class="">it's a bug or ANSI CL allows this?<br class=""></div></blockquote></div><div class=""><br class=""></div>Depends.<div class=""><br class=""></div><div class="">ANSI CL specifies the lisp reader in such a way that (2 . 5 . 5) is not a valid syntax.</div><div class="">However, ANSI CL specifies that implementation may extend the CL language, UNDER THE CONDITION that extensions BE DOCUMENTED.</div><div class=""><br class=""></div><div class="">Therefore, IF it is written in ABCL documentation that (2 . 5 . x) reads as (2 . 5) </div><div class="">THEN it is not a bug, but an ABCL specific extension,</div><div class="">ELSE it is a conformity bug, it should signal a READER-ERROR (or perhaps just an ERROR).</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Notice that since this is an extensions on the reader macro character #\(, it could be expected that the standard reader macro character for #\( still exist in the system and be obtained by (copy-readtable NIL) which shall return the standard readtable.</div><div class="">For example, in ccl the default *readtable* is poluted by a lot of extensions such as the dispatching #/ #_ #$ macro characters, but you can throw them away with (setf *readtable* (copy-readtable NIL)). One could expect the same here.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><a href="http://www.lispworks.com/documentation/HyperSpec/Body/02_da.htm" class="">http://www.lispworks.com/documentation/HyperSpec/Body/02_da.htm</a></div><div class=""><a href="http://www.lispworks.com/documentation/HyperSpec/Body/01_f.htm" class="">http://www.lispworks.com/documentation/HyperSpec/Body/01_f.htm</a></div><div class=""><a href="http://www.lispworks.com/documentation/HyperSpec/Body/f_cp_rdt.htm" class="">http://www.lispworks.com/documentation/HyperSpec/Body/f_cp_rdt.htm</a></div><div class=""><div class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">-- <br class="">__Pascal J. Bourguignon__<br class=""><br class=""><br class=""></div></div>
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