<div dir="auto">Yes. Actually it assumes slightly less, it assumes the values of the block can be added (and thus multiplied by a natural number n, which means adding it to itself n times and it is always possible and should be implemented as #*). The main use of #sum: is with blocks that evaluate to Numbers, but it works for more general objects.</div><div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, 3 Nov 2022 at 12:25 Andres Valloud via Cuis-dev <<a href="mailto:cuis-dev@lists.cuis.st">cuis-dev@lists.cuis.st</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">The message #sum: seemingly assumes the presence of a ring where the messages + and * are coordinated. On 11/2/22 9:57 PM, Luciano Notarfrancesco via Cuis-dev wrote: > Yes, the method assumes the block is a function (it maps one element to > only one value). We talked about this here a couple of times. The > Collection protocol is very “functional”, specially messages like > #collect:, #select:, #detect:, etc, and using them with blocks that are > functions is the most natural way to use them, and I don’t think we > loose anything by making the assumption that the blocks for these > messages are functions. > Moreover, the whole point of Bag is to be able to efficiently store > elements with lots of repetitions, possibly millions of repetitions that > otherwise wouldn’t even fit in memory. If #sum: iterated over all the > repetitions it would defeat the original purpose of Bag. And I argue > that this is not necessary because no one would ever call #sum: with a > block that is not a function, at least I never had the need to do that, > and it feels unnatural to use #sum: in that way and I’d use #do: instead. > If you think this assumption is strange, think about all the other > assumptions that collections make. For example, you cannot change a > collection while you’re iterating it. It would just feel wrong to change > a collection while you iterate it, we don’t need to try to support that > because who would do that? > > > On Thu, 3 Nov 2022 at 03:12 Hernán Wilkinson > <<a href="mailto:hernan.wilkinson@10pines.com" target="_blank">hernan.wilkinson@10pines.com</a> <mailto:<a href="mailto:hernan.wilkinson@10pines.com" target="_blank">hernan.wilkinson@10pines.com</a>>> wrote: > > How does that optimization work? > Because I thought about evaluating the block and multiplying that > for the number of elements, but that makes sense if the block > returns always the same value por the same element, if it does not > then it will not work... > > > On Wed, Nov 2, 2022 at 3:24 PM Juan Vuletich <<a href="mailto:juan@cuis.st" target="_blank">juan@cuis.st</a> > <mailto:<a href="mailto:juan@cuis.st" target="_blank">juan@cuis.st</a>>> wrote: > > __ > On 11/1/2022 11:23 PM, Hernán Wilkinson via Cuis-dev wrote: >> yeap, the current implementation is not correct. >> Juan, attached is a change set that fixes it and another with >> the related tests. >> >> Cheers! >> Hernan. >> >> On Tue, Nov 1, 2022 at 3:39 AM Luciano Notarfrancesco >> <<a href="mailto:luchiano@gmail.com" target="_blank">luchiano@gmail.com</a> <mailto:<a href="mailto:luchiano@gmail.com" target="_blank">luchiano@gmail.com</a>>> wrote: >> >> I’m afk right now so I cannot check, but it sounds like I >> made a mistake. Of course it should be the value of aBlock >> at each element times the number of occurrences. >> >> On Tue, 1 Nov 2022 at 07:33 Hernán Wilkinson >> <<a href="mailto:hernan.wilkinson@10pines.com" target="_blank">hernan.wilkinson@10pines.com</a> >> <mailto:<a href="mailto:hernan.wilkinson@10pines.com" target="_blank">hernan.wilkinson@10pines.com</a>>> wrote: >> >> Hi, >> the implementation of Bag>>#sum: aBlock ifEmpty: >> emptyBlock does not use the parameter aBlock at all >> and assumes that each of the elements answers the >> message * >> @Luciano Notarfrancesco >> <mailto:<a href="mailto:luchiano@gmail.com" target="_blank">luchiano@gmail.com</a>> the implementation is >> yours and it is very new? Is there a reason you did >> that way? >> >> Thanks >> Hernan >> >> >> -- >> *Hernán Wilkinson >> Agile Software Development, Teaching & Coaching* >> *Phone: +54-011*-4893-2057 >> *Twitter: @HernanWilkinson* >> *site: <a href="http://www.10Pines.com" rel="noreferrer" target="_blank">http://www.10Pines.com</a> <<a href="http://www.10pines.com/" rel="noreferrer" target="_blank">http://www.10pines.com/</a>>* >> Address: Alem 896, Floor 6, Buenos Aires, Argentina >> >> >> >> -- >> *Hernán Wilkinson >> Agile Software Development, Teaching & Coaching* >> *Phone: +54-011*-4893-2057 >> *Twitter: @HernanWilkinson* >> *site: <a href="http://www.10Pines.com" rel="noreferrer" target="_blank">http://www.10Pines.com</a> <<a href="http://www.10pines.com/" rel="noreferrer" target="_blank">http://www.10pines.com/</a>>* >> Address: Alem 896, Floor 6, Buenos Aires, Argentina > > Hi Hernán, > > Your fix disables the optimization Luciano did. I chose to fix > Luciano's code. Did the same for #product: (same bug). > Integrated your tests, and added another one for #product: > > Thanks, > > -- > Juan Vuletich > <a href="http://cuis.st" rel="noreferrer" target="_blank">cuis.st</a> <<a href="http://cuis.st" rel="noreferrer" target="_blank">http://cuis.st</a>> > <a href="http://github.com/jvuletich" rel="noreferrer" target="_blank">github.com/jvuletich</a> <<a href="http://github.com/jvuletich" rel="noreferrer" target="_blank">http://github.com/jvuletich</a>> > <a href="http://researchgate.net/profile/Juan-Vuletich" rel="noreferrer" target="_blank">researchgate.net/profile/Juan-Vuletich</a> <<a href="http://researchgate.net/profile/Juan-Vuletich" rel="noreferrer" target="_blank">http://researchgate.net/profile/Juan-Vuletich</a>> > <a href="http://independent.academia.edu/JuanVuletich" rel="noreferrer" target="_blank">independent.academia.edu/JuanVuletich</a> <<a href="http://independent.academia.edu/JuanVuletich" rel="noreferrer" target="_blank">http://independent.academia.edu/JuanVuletich</a>> > <a href="http://patents.justia.com/inventor/juan-manuel-vuletich" rel="noreferrer" target="_blank">patents.justia.com/inventor/juan-manuel-vuletich</a> <<a href="http://patents.justia.com/inventor/juan-manuel-vuletich" rel="noreferrer" target="_blank">http://patents.justia.com/inventor/juan-manuel-vuletich</a>> > <a href="http://linkedin.com/in/juan-vuletich-75611b3" rel="noreferrer" target="_blank">linkedin.com/in/juan-vuletich-75611b3</a> <<a href="http://linkedin.com/in/juan-vuletich-75611b3" rel="noreferrer" target="_blank">http://linkedin.com/in/juan-vuletich-75611b3</a>> > <a href="http://twitter.com/JuanVuletich" rel="noreferrer" target="_blank">twitter.com/JuanVuletich</a> <<a href="http://twitter.com/JuanVuletich" rel="noreferrer" target="_blank">http://twitter.com/JuanVuletich</a>> > > > > -- > *Hernán Wilkinson > Agile Software Development, Teaching & Coaching* > *Phone: +54-011*-4893-2057 > *Twitter: @HernanWilkinson* > *site: <a href="http://www.10Pines.com" rel="noreferrer" target="_blank">http://www.10Pines.com</a> <<a href="http://www.10pines.com/" rel="noreferrer" target="_blank">http://www.10pines.com/</a>>* > Address: Alem 896, Floor 6, Buenos Aires, Argentina > > -- Cuis-dev mailing list <a href="mailto:Cuis-dev@lists.cuis.st" target="_blank">Cuis-dev@lists.cuis.st</a> <a href="https://lists.cuis.st/mailman/listinfo/cuis-dev" rel="noreferrer" target="_blank">https://lists.cuis.st/mailman/listinfo/cuis-dev</a> </blockquote></div></div>