<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Oct 14, 2009, at 8:38 AM, james anderson wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">
<br><div><div>On 2009-10-14, at 10:55 , Tim Bradshaw wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">On 13 Oct 2009, at 16:43, Daniel Weinreb wrote:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> <blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">There are two separate questions here: what is the</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">definition of the Common Lisp language, and what</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">should CCL do?</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Regarding the former, I think I can say pretty reliably</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">that during the design of CL, nobody thought about</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">this.<span class="Apple-converted-space"> </span>So the spec is not written in such a way as to</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">give unambiguous guidance about what these forms</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">ought to do.</div> </blockquote><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">I agree with this.<span class="Apple-converted-space"> </span>However I think it's clear that, if they had <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">thought about it, they would not have mandated the kind of obscure <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">accidental name-capture that CCL does (and which other implementations <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">may well do as well), if only because it would give the hygienic macro <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">people cause to poke fun at CL.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">I think one could argue from this text: "The slot default init forms <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">are evaluated in the lexical environment in which the defstruct form <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">itself appears and in the dynamic environment in which the call to the <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">constructor function appears." that CCL (and some other <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">implementations) are wrong.<span class="Apple-converted-space"> </span>However this is not clear enough since <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">"the defstruct form" needs to be something like "the defstruct form <span class="Apple-converted-space"> </span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">which introduces the init form".</div></blockquote><div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"><br></span></font></div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;">i do not read the spec to bear this out. while the passage with respect to default initargs in 7.1.3 does extend this environment's description, as in:</span></font></div><div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"><br></span></font></div><div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"> The default value </span></font><a href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_f.htm#form"><font color="#001fde" style="color: #001fde"><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;">form</span></font></font></a><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"> is evaluated in the lexical environment of the </span></font><a href="http://www.lispworks.com/documentation/HyperSpec/Body/m_defcla.htm#defclass"><font color="#391974" style="color: #391974"><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;">defclass</span></font></font></a><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"> form that supplied it.</span></font></div><div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;"><br></span></font></div><div><font class="Apple-style-span" size="2"><span class="Apple-style-span" style="font-size: 10px;">this passage is part of a separate text which discusses the interpretation of the default initargs, and does not benefit from being in the context of a specification for the interpretation of a particular definition form. the analogous passage in the specification of the defclass operator does not qualify the specification. that is, it suffices with the designation "the defclass form". <span class="Apple-style-span" style="font-size: medium; ">i cannot recall any occasion to have wondered if i should even consider this to refer to anything other than the lexical context of the respective base class definition form.</span></span></font></div><div><font class="Apple-style-span" face="Times" size="4"><span class="Apple-style-span" style="font-size: 16px;"><font class="Apple-style-span" face="Monaco"><span class="Apple-style-span" style="font-size: medium;"><br></span></font></span></font></div></div></blockquote><div><br></div><div>I agree with you completely. But read the recent C.L.L. thread on "DEFSTRUCT and lexical environment" if you want to see the arguments for the opposing view. They are being advanced with (IMHO) improbable vehemence.</div><div><br></div><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>one should be able to expect expressions in the language to specify coherent behavior.</div></div></div></blockquote></div><br><div>Yeah, you'd think, wouldn't you.</div><div><br></div><div>rg</div><div><br></div></body></html>