I see. Regarding the point about protocol performance optimization, I wonder if this would be that confusing, given this is already the case with Enum.count/1 (optimizeable by Enumerable protocol) VS Enum.count/2 (not optimized)?
But Enum.reduce works fine for my case, so this clearly isn't a blocker or anything :) Le ven. 23 juil. 2021 à 15:51, José Valim <jose.va...@dashbit.co> a écrit : > I have thought about this a couple of times but another discussion we keep > having is to make Enum.sum/1 part of a protocol for performance and then we > wouldn't be able to optimize it in the Enum.sum/2 variant. I wonder if that > can be confusing. So for now, I would go the reduce route if you are really > worried about performance here. > > On Fri, Jul 23, 2021 at 6:51 AM Sabiwara Yukichi <sabiw...@gmail.com> > wrote: > >> Hi! >> >> Recently I found myself several times in a situation where I needed to >> sum from an enumerable after applying a transformation, e.g. sum one field >> from a list of structs. >> There is a temptation to use Enum.map(list, fun) |> Enum.sum() which >> would be wasteful since it needs to build the intermediate list. >> Enum.reduce(list, 0, &(fun.(&1) + &2) works but it is less >> straightforward and less explicit about the intent. >> >> I wondered if Enum.sum(list, fun) (or Enum.sum_by(list, fun)?) could be >> a nice addition that would be consistent with some other Enum functions >> such as Enum.count/2, Enum.any?/2. What do you think? >> >> My branch for reference: >> https://github.com/elixir-lang/elixir/compare/master...sabiwara:sum/2?expand=1 >> >> -- >> You received this message because you are subscribed to the Google Groups >> "elixir-lang-core" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to elixir-lang-core+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/elixir-lang-core/CANnyohZtg19ES%2B52KzCX%3DYnY-rgaLoNcnuRaCyrmtbMpTQ1NDg%40mail.gmail.com >> <https://groups.google.com/d/msgid/elixir-lang-core/CANnyohZtg19ES%2B52KzCX%3DYnY-rgaLoNcnuRaCyrmtbMpTQ1NDg%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > -- > You received this message because you are subscribed to the Google Groups > "elixir-lang-core" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to elixir-lang-core+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4%2B5JXO-tt2JN5k-R_vmv8nOgw7bjzO%2BhXJ2CnanoAwp-A%40mail.gmail.com > <https://groups.google.com/d/msgid/elixir-lang-core/CAGnRm4%2B5JXO-tt2JN5k-R_vmv8nOgw7bjzO%2BhXJ2CnanoAwp-A%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "elixir-lang-core" group. To unsubscribe from this group and stop receiving emails from it, send an email to elixir-lang-core+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CANnyohad6B1Vvosp6e9xsRVY8_g0Yv7KLzyeSO%2Bi6RQvqcz4Tg%40mail.gmail.com.
