From: shevegen@... Date: 2017-07-30T13:36:51+00:00 Subject: [ruby-core:82211] [Ruby trunk Feature#13777] Array#delete_all Issue #13777 has been updated by shevegen (Robert A. Heiler). I myself usually use .reject! and .select! and then apply the reverse prior to that if I need to keep these entries as well (or respectively without the '!'). My approach also needs more lines. If I understood it correctly so then you want to have an operation where you can not only manipulate the variable at hand, but also additionally select the entries that were deleted. I do not know of a better way than the one you showed though, at the least not with any fewer lines of code. ---------------------------------------- Feature #13777: Array#delete_all https://bugs.ruby-lang.org/issues/13777#change-65978 * Author: k0kubun (Takashi Kokubun) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- I want Array#delete_if which returns array of deleted values. For following code, ~~~ array = ["a", "aa", "ab", "bb", "c"] result = {} until array.empty? key = array.first group, array = array.partition { |v| v.start_with?(key) } result[key] = group end result #=> {"a"=>["a", "aa", "ab"], "bb"=>["bb"], "c"=>["c"]} ~~~ With Array#delete_all, This would be able to be written in more elegant way like: ~~~ array = ["a", "aa", "ab", "bb", "c"] result = {} until array.empty? key = array.first result[key] = array.delete_all { |v| v.start_with?(key) } end result #=> {"a"=>["a", "aa", "ab"], "bb"=>["bb"], "c"=>["c"]} ~~~ This is simplified source code of real use case in Haml: https://github.com/haml/haml/blob/923a0d78874fe1d369f8c7a0bf77f67b2c2139bb/lib/haml/attribute_compiler.rb#L75-L76 This grouping task is necessary for Haml optimization. Do you know simpler way to write this with existing methods? -- https://bugs.ruby-lang.org/ Unsubscribe: