Issue #11076 has been updated by jonathanhefner (Jonathan Hefner). > "map + select" is much more frequent, but it is not introduced yet I think it would also be nice if `filter_map` was added. However, a specif= ic justification for adding `tally_by` is to avoid an extra array allocatio= n. `filter_map` can already be expressed as `map { ... }.compact!` to avoi= d allocating an extra array. But there is no way to avoid an extra allocat= ion with `map { ... }.tally`. ---------------------------------------- Feature #11076: Enumerable method count_by https://bugs.ruby-lang.org/issues/11076#change-77888 * Author: haraldb (Harald B=F6ttiger) * Status: Closed * Priority: Normal * Assignee: nobu (Nobuyoshi Nakada) * Target version: = ---------------------------------------- I very often use `Hash[array.group_by{|x|x}.map{|x,y|[x,y.size]}]`. Would be nice with to have a method called `count_by`: ~~~ruby array =3D ['aa', 'aA', 'bb', 'cc'] p array.count_by(&:downcase) #=3D> {'aa'=3D>2,'bb'=3D>1,'cc'=3D>1} ~~~ -- = https://bugs.ruby-lang.org/ Unsubscribe: <mailto:ruby-core-request / ruby-lang.org?subject=3Dunsubscribe> <http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>