<div dir="ltr"><div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Ah! I did not know that I could use `self` to refer to the class in a class method</blockquote><div> Everything you can do on the instance side you can also do over the class side, it is the same, only shifted by one metalevel.<br></div><div><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">I didn't know I could return early in a method<br></blockquote><div>Non-local return seems to fit Smalltalk. Also sparks <a href="http://lambda-the-ultimate.org/node/2009">lots of debate</a> for some reason. Does anybody know where and when the term “full closure” was coined?<br><br>-- <br></div><div>Eze<br></div></div><div><div><div><div><div></div></div></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, 6 Jun 2024 at 14:09, Mark Volkmann via Cuis-dev <<a href="mailto:cuis-dev@lists.cuis.st">cuis-dev@lists.cuis.st</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">Andres, thank you so much for the feedback! I didn't know I could return early in a method like you showed and hadn't considered the difference between / and //.</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jun 5, 2024 at 5:37 PM Andres Valloud via Cuis-dev <<a href="mailto:cuis-dev@lists.cuis.st" target="_blank">cuis-dev@lists.cuis.st</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">Hi, ifTrue: is supposed to take a block argument, so it should be <br>
ifTrue: [nil]. And to prevent indenting the entire method, consider<br>
<br>
self < 1 ifTrue: [^nil].<br>
... etc...<br>
^seq<br>
<br>
It's perfectly fine to have multiple return statements.<br>
<br>
By the way, use // 2 instead of / 2, because / 2 will try to make a <br>
fraction to then discover that next was even. But now you know next is <br>
even, so you can do next // 2. Using / is still correct of course.<br>
<br>
I wouldn't worry about doing bitShift: -1 instead of // 2 here. That <br>
kind of "speedup" is barking at the wrong forest (not even the wrong <br>
tree) from the perspective of Collatz. I would familiarize myself with <br>
the difference between the pairs "//, \\", "quo:, rem:", and "div:, <br>
mod:", however.<br>
<br>
On 6/5/24 11:16 AM, Mark Volkmann via Cuis-dev wrote:<br>
> I took another shot at simplifying the code. I didn't need to use <br>
> recursion. I can do this instead as an instance method added to the <br>
> Integer class:<br>
> <br>
> collatz<br>
> "answers an OrderedCollection containing the Collatz sequence for <br>
> this integer"<br>
> <br>
> | next seq |<br>
> ^self < 1<br>
> ifTrue: nil<br>
> ifFalse: [<br>
> next := self.<br>
> seq := OrderedCollection new.<br>
> seq addLast: next.<br>
> [next = 1] whileFalse: [<br>
> next := next even ifTrue: [next / 2] ifFalse: [next * 3 + 1].<br>
> seq addLast: next<br>
> ].<br>
> ^seq<br>
> ]<br>
> <br>
> Beside the lack of memoization and the "orbit" concept, what would you <br>
> change about this?<br>
> <br>
> <br>
> On Wed, Jun 5, 2024 at 12:40 PM Mark Volkmann <<a href="mailto:r.mark.volkmann@gmail.com" target="_blank">r.mark.volkmann@gmail.com</a> <br>
> <mailto:<a href="mailto:r.mark.volkmann@gmail.com" target="_blank">r.mark.volkmann@gmail.com</a>>> wrote:<br>
> <br>
> See my replies inline below with some parts snipped to focus my replies.<br>
> <br>
> On Wed, Jun 5, 2024 at 12:19 PM Andres Valloud via Cuis-dev<br>
> <<a href="mailto:cuis-dev@lists.cuis.st" target="_blank">cuis-dev@lists.cuis.st</a> <mailto:<a href="mailto:cuis-dev@lists.cuis.st" target="_blank">cuis-dev@lists.cuis.st</a>>> wrote:<br>
> <br>
> Always be on the lookout for when a receiver is just self. <br>
> Otherwise,<br>
> the code is not using the knowledge it has of where it is<br>
> implemented<br>
> (and this leads to all sorts of problems later).<br>
> <br>
> <br>
> Ah! I did not know that I could use `self` to refer to the class in<br>
> a class method.<br>
> <br>
> Also, you can accomplish the same with much less code. Any time<br>
> you<br>
> have a class whose class methods offer a "service" but do not<br>
> really<br>
> have instances, you should suspect the code should be placed<br>
> elsewhere.<br>
> <br>
> <br>
> I see that I don't need the next: method and can just move that code<br>
> in the gather:seq: method.<br>
> But it's not apparent to me what else I can do to make the code shorter.<br>
> <br>
> Side comment: I've been working on the Collatz problem for a *long*<br>
> time, so I have quite a few opinions on how to go about writing<br>
> specifically this code...<br>
> <br>
> <br>
> I know I could add caching of results to make subsequent calls with<br>
> different integers much faster.<br>
> <br>
> But in this particular case, what you're collecting is the orbit<br>
> of an<br>
> integer (so, anInteger, not aNumber).<br>
> <br>
> <br>
> Excellent point! I changed every occurrence of `aNumber` to<br>
> `anInteger` in my code.<br>
> <br>
> -- <br>
> R. Mark Volkmann<br>
> Object Computing, Inc.<br>
> <br>
> <br>
> <br>
> -- <br>
> R. Mark Volkmann<br>
> Object Computing, Inc.<br>
> <br>
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</blockquote></div><br clear="all"><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div><font face="arial, helvetica, sans-serif">R. Mark Volkmann</font></div><div><span style="font-size:12.8px"><font face="arial, helvetica, sans-serif">Object Computing, Inc.</font></span></div></div></div></div></div></div></div></div>
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