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<p>Woah, I didn't know that this topic has been such a hot potato. :-)</p>
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<div><font size="3" color="black"><span style="font-size:12pt"><a href="http://www.hpi.de/" target="_blank" rel="noopener noreferrer" id="LPNoLP"><font size="2"><span id="LPlnk909538"><font color="#757B80"></font></span></font></a></span></font></div>
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<div class="x__rp_T4" id="x_Item.MessagePartBody">In my opinion, people can always abuse a (domain-specific) language to write bad code and you cannot really stop them from doing so by limiting the features of the language. Instead of banning a protocol, people
should understand *why* and *when* it is a bad idea to use them. #caseOf: & Co. can be used and can be abused, so I vote for keeping and legalizing it (otherwise we have to destroy every bread knife, too).</div>
<div class="x__rp_T4" id="x_Item.MessagePartBody">If we stigmatize #caseOf:, we could also stigmatize or even deprecate #isKindOf: because very often, it is abused - but still, it can be useful in many situations where you need metaprogramming indeed, for example,
Exception class >> #handles:.</div>
<div class="x__rp_T4" id="x_Item.MessagePartBody">LBNL, I often consider both concepts as the first step of a larger refactoring. Alone for this purpose, I would like to keep these selectors.</div>
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<div class="x__rp_T4" id="x_Item.MessagePartBody">Best,</div>
<div class="x__rp_T4" id="x_Item.MessagePartBody">Christoph</div>
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<div id="x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Von:</b> Squeak-dev <squeak-dev-bounces@lists.squeakfoundation.org> im Auftrag von tim Rowledge <tim@rowledge.org><br>
<b>Gesendet:</b> Sonntag, 28. März 2021 19:07:58<br>
<b>An:</b> The general-purpose Squeak developers list<br>
<b>Betreff:</b> Re: [squeak-dev] #identityCaseOf:</font>
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> On 2021-03-28, at 4:09 AM, Thiede, Christoph <Christoph.Thiede@student.hpi.uni-potsdam.de> wrote:<br>
> <br>
> @Tim:<br>
> <br>
> > Far too like C.<br>
> <br>
> Again, why please? :-) I'm not a big fan of C either, but IMO switch/select/case is not the worst concept when it allows you to eliminate some duplication.
<br>
<br>
It (both C and caseOf*) has its uses but my practical issue with caseOf* in Smalltalk is that I keep (very subjective and personal experience dependant) seeing it get used in ways that completely sidestep Smalltalk and implement bad C idiom. A bit like isKindOf:
and isBlahClass.<br>
<br>
e.g.<br>
foo class<br>
caseOf: {<br>
[Rabbit] -> [foo doRabbitThing].<br>
[Fox] -> [foo doFoxThing]}<br>
... which of course merely (badly) replicates class lookup/inheritance/message-sending. It suggests a writer that cannot escape the mental prison of C-like assault coding.<br>
<br>
isKindOf: is a useful meta-programming idiom that I've seen used inside inner loops to do the same sort of not-message-sending. I've even had people try to justify is on the grounds that "sending messages is so slow and I want ot avoid it", which is just nuts.<br>
<br>
isBlahClass is almost as horrible but at least has the excuse of (hopefully) being part of a not yet completed cleaning of other nastiness.<br>
<br>
Part of the problem is that language flexibility always ends up being a tool that lets annoying people write bad FORTRAN in any language. And then somebody has to spend a too large fraction of their life trying to fix it.<br>
<br>
tim<br>
--<br>
tim Rowledge; tim@rowledge.org; <a href="http://www.rowledge.org/tim">http://www.rowledge.org/tim</a><br>
Useful random insult:- Not enough sense to come in out of the rain.<br>
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