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<p>Hm, maybe we will never now - the crux of ternary logic ;-)</p>
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<p>But actually, I wonder whether any of these calls to "something class canUnderstand: aSelector" is useful, shouldn't we rather replace a big part of them with "something respondsTo: aSelector"?</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>Von:</b> Squeak-dev <squeak-dev-bounces@lists.squeakfoundation.org> im Auftrag von Jakob Reschke <forums.jakob@resfarm.de><br>
<b>Gesendet:</b> Freitag, 31. Januar 2020 18:23:19<br>
<b>An:</b> The general-purpose Squeak developers list<br>
<b>Betreff:</b> Re: [squeak-dev] Should you override #doesNotUnderstand: and #respondsTo: together?</font>
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<div dir="auto">*maybe* it was also a joke :-)</div>
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<div dir="ltr" class="gmail_attr">Thiede, Christoph <<a href="mailto:Christoph.Thiede@student.hpi.uni-potsdam.de">Christoph.Thiede@student.hpi.uni-potsdam.de</a>> schrieb am Fr., 31. Jan. 2020, 18:22:<br>
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<p>When would you use this third boolean concretely? To me, this sounds rather like an overengineering solution, maybe premature optimization, for now ... :-)</p>
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<p>Best,</p>
<p>Christoph</p>
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<div id="m_3592583892095674379divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>Von:</b> Squeak-dev <<a href="mailto:squeak-dev-bounces@lists.squeakfoundation.org" target="_blank" rel="noreferrer">squeak-dev-bounces@lists.squeakfoundation.org</a>>
im Auftrag von Jakob Reschke <<a href="mailto:forums.jakob@resfarm.de" target="_blank" rel="noreferrer">forums.jakob@resfarm.de</a>><br>
<b>Gesendet:</b> Freitag, 31. Januar 2020 18:16:51<br>
<b>An:</b> The general-purpose Squeak developers list<br>
<b>Betreff:</b> Re: [squeak-dev] Should you override #doesNotUnderstand: and #respondsTo: together?</font>
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<div dir="auto">Regarding canUnderstand:, maybe it's time for the third boolean called "it depends" or "maybe". ;-)</div>
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<div dir="ltr" class="gmail_attr">Thiede, Christoph <<a href="mailto:Christoph.Thiede@student.hpi.uni-potsdam.de" target="_blank" rel="noreferrer">Christoph.Thiede@student.hpi.uni-potsdam.de</a>> schrieb am Fr., 31. Jan. 2020, 10:43:<br>
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<p>> <span>Question is, should X class>>canUnderstand: be overwritten, too?</span></p>
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<p><span>This would not be possible in my example, would it? Each json object understands different keys ... This is also why I favor #respondsTo: over #canUnderstand: in general.</span></p>
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<p>Best,</p>
<p>Christoph</p>
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<div id="m_3592583892095674379m_-2230043140418705437x_divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>Von:</b> Squeak-dev <<a href="mailto:squeak-dev-bounces@lists.squeakfoundation.org" rel="noreferrer noreferrer" target="_blank">squeak-dev-bounces@lists.squeakfoundation.org</a>>
im Auftrag von Tobias Pape <<a href="mailto:Das.Linux@gmx.de" rel="noreferrer noreferrer" target="_blank">Das.Linux@gmx.de</a>><br>
<b>Gesendet:</b> Freitag, 31. Januar 2020 10:30:20<br>
<b>An:</b> The general-purpose Squeak developers list<br>
<b>Betreff:</b> Re: [squeak-dev] Should you override #doesNotUnderstand: and #respondsTo: together?</font>
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> On 31.01.2020, at 10:14, Thiede, Christoph <<a href="mailto:Christoph.Thiede@student.hpi.uni-potsdam.de" rel="noreferrer noreferrer" target="_blank">Christoph.Thiede@student.hpi.uni-potsdam.de</a>> wrote:<br>
> <br>
> Hi all,<br>
> <br>
> just struggled over the fact that Json objects provide access to their keys via #doesNotUnderstand:, but they do not override #respondsTo:. Example:<br>
> <br>
> json := Json readFromString: '{"foo": 42}'.<br>
> json foo. "42"<br>
> json respondsTo: #foo. "false"<br>
> <br>
> Question: Is this discrepancy indeed desired behavior? Or should we rather always try to override #doesNotUnderstand: and #respondsTo: together?<br>
<br>
This is actually done very seldom, IIRC.<br>
But maybe a good pattern, tho. Question is, should X class>>canUnderstand: be overwritten, too?<br>
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Best regards<br>
-Tobias<br>
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> <br>
> Best,<br>
> Christoph<br>
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