<div dir="ltr">... and I can always CHANGE-CLASS, can't I?<br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sun, Feb 7, 2021 at 9:46 AM Hans Hübner <<a href="mailto:hans.huebner@gmail.com">hans.huebner@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div dir="ltr">Am So., 7. Feb. 2021 um 09:35 Uhr schrieb Manfred Bergmann <<a href="mailto:manfred.bergmann@me.com" target="_blank">manfred.bergmann@me.com</a>>:<br></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">> Am 07.02.2021 um 09:23 schrieb Hans Hübner <<a href="mailto:hans.huebner@gmail.com" target="_blank">hans.huebner@gmail.com</a>>:<br>
> <br>
> Am So., 7. Feb. 2021 um 09:20 Uhr schrieb Manfred Bergmann <<a href="mailto:manfred.bergmann@me.com" target="_blank">manfred.bergmann@me.com</a>>:<br>
> But fundamentally, you also can’t create an instance of a class in Common Lisp from just the symbol. The class definition must be known.<br>
> <br>
> This simply is untrue.  You can use FIND-CLASS to find a class named by a symbol and then instantiate it.<br>
<br>
Well, OK. Sure. But when I do that I have again a dependency on the concrete class, or? And it would be similar as knowing the class right from the start.<br></blockquote><div><br></div><div>You don't.  You have a dependency on the name of a class.  The name could refer to two entirely different classes between invocations of FIND-CLASS.  The name could also come from an external source.  Thus, this is purely a run-time dependency and it would be quite possible that FIND-CLASS returns NIL if given a symbol that does not designate a currently-defined class. </div></div></div>
</blockquote></div><br clear="all"><br>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">Marco Antoniotti, Associate Professor</span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:pre;word-spacing:0px;text-decoration:none">             </span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:pre;word-spacing:0px;text-decoration:none"> </span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">tel.</span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;text-decoration:none;display:inline;float:none;white-space:pre"> </span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">+39 - 02 64 48 79 01</span><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">DISCo, Università Milano Bicocca U14 2043</span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:pre;word-spacing:0px;text-decoration:none">     </span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:pre;word-spacing:0px;text-decoration:none"> </span><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:pre;word-spacing:0px;text-decoration:none"></span><a href="http://bimib.disco.unimib.it/" style="font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px" target="_blank">http://bimib.disco.unimib.it</a><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">Viale Sarca 336</span><br style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:14px;font-style:normal;font-weight:normal;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration:none;display:inline;float:none">I-20126 Milan (MI) ITALY</span><br></div></div></div></div>