From: knu@... Date: 2019-11-28T06:24:59+00:00 Subject: [ruby-core:96010] [Ruby master Feature#16261] Enumerable#each_splat and Enumerator#splat Issue #16261 has been updated by knu (Akinori MUSHA). I agree this feature would be a nice addition. Actually I had exactly the same idea, presented at Rails Developer Meetup 2019: https://www.slideshare.net/akinorimushaevolution-of-enumerator There's a subtle difference between Hash#each/map and Hash#select/reject in how they yield each key-value pair. ```ruby {a:1,b:2}.select{|x|p x} # :a # :b {a:1,b:2}.each{|x|p x} # [:a, 1] # [:b, 2] ``` I guess this was an unintended difference, but we cannot fix it by now for compatibility reasons, and each_splat would be one way to work around it. ---------------------------------------- Feature #16261: Enumerable#each_splat and Enumerator#splat https://bugs.ruby-lang.org/issues/16261#change-82848 * Author: zverok (Victor Shepelev) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- **UPD:** After discussion in comments, method names changed to "splat"-based. New methods proposal. Prototype code: ```ruby module Enumerable def each_splat return to_enum(__method__) unless block_given? each_entry { |item| yield(*item) } # unpacking possible array into several args end end class Enumerator def splat return to_enum(:splat) unless block_given? each_entry { |item| yield(*item) } end end ``` Supposed documentation/explanation: > For enumerable with Array items, passes all items in the block provided as a separate arguments. t could be useful if the provided block has lambda semantics, e.g. doesn't unpack arguments automatically. For example: ```ruby files = ["README.md", "LICENSE.txt", "Contributing.md"] content = [fetch_readme, fetch_license, fetch_contributing] # somehow make a content for the files files.zip(content).each_splat(&File.:write) # writes to each file its content ``` > When no block passed, returns enumerator of the tuples: ```ruby [1, 2, 3].zip([4, 5, 6]).each_splat.map(&:+) # => [5, 7, 9] ``` -- https://bugs.ruby-lang.org/ Unsubscribe: