<br><br><div class="gmail_quote">On Wed, Nov 11, 2009 at 3:14 PM, Russell N Hyer <span dir="ltr"><<a href="mailto:hrothgar.ofstingan@gmail.com">hrothgar.ofstingan@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
I still don't comprehend the purpose behind having more than one<br>
flavour of empty in regards to empty set based mathematics.<br></blockquote><div><br></div><div>nil is an object like any other, and Sets can contain arbitrary objects.</div><div>An empty Set contains no objects. The fact that internally an empty Set has some slots intialized to nil is an implementation detail that in no way implies that it contains nil.</div>
<div><br></div><div>So if sets are capable of including arbitrary objects they should be able to contain nil. There are lots of contexts in which having collections that can include nil is useful. The compiler is one. Storing and reconstituting object graphs is another.</div>
<div><br></div><div>Or in summary nil ~~ #isEmpty.</div><div><br></div><div>HTH</div><div>Eliot</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
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2009/11/11, Igor Stasenko <<a href="mailto:siguctua@gmail.com">siguctua@gmail.com</a>>:<br>
> Just want to add that enabling a set to contain nils already discussed<br>
> before.<br>
><br>
> <a href="http://n4.nabble.com/squeak-dev-Letting-Set-contain-nils-td69437.html#a69437" target="_blank">http://n4.nabble.com/squeak-dev-Letting-Set-contain-nils-td69437.html#a69437</a><br>
><br>
> ... and as you may guess, i supporting Levente in this :)<br>
><br>
> --<br>
> Best regards,<br>
> Igor Stasenko AKA sig.<br>
><br>
><br>
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</blockquote></div><br>