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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elixir-lang-core/CANnyohZtg19ES%2B52KzCX%3DYnY-rgaLoNcnuRaCyrmtbMpTQ1NDg%40mail.gmail.com.
