From: "trans (Thomas Sawyer)" Date: 2012-06-17T06:27:18+09:00 Subject: [ruby-core:45675] [ruby-trunk - Bug #6596] New method for Arrays : Array#index Issue #6596 has been updated by trans (Thomas Sawyer). =begin @knu I think you have already pointed out the usecase. Wherever someone is using #each_with_index which contains a conditional selection would be a potential use case. even_indexes = [] array_of_numbers.each_with_index do |c, i| next if c % 2 == 1 even_indexes << i end Basically #indexes is to #index as #select is to #find. We could do without #select too, but why would we? =end ---------------------------------------- Bug #6596: New method for Arrays : Array#index https://bugs.ruby-lang.org/issues/6596#change-27274 Author: robin850 (Robin Dupret) Status: Feedback Priority: Normal Assignee: Category: core Target version: 2.0.0 ruby -v: 2.0.0 Hello 5 days ago, I submitted a pull request on Github which provides a new method for the array objects which is Array#indexes. I have fist edit the Array#index method in order it to return an array of indexes and not a single index (which is the first occurrence it finds). I found it more logical but a user (trans) tells us that it could break the contract of Array#index so I decided to move it into Array#indexes. Eric (drbrain) tells me I should reasonning why I want to add this method ; it's just a point of view : I don't really understand why Array#index return a single index if the parameter is in the array several times. Examples a = [1, 2, 3, 1] a.indexes(1) Return : [0, 3] a.index(1) Return : 0 In my opinion, it's not really logical, 1 is in the array twice Moreover, this pull request doesn't beak anything because we don't edit the Array#index method so programms which were created with previous version of Ruby will work. I hope my post is complete. Have a nice day. -- http://bugs.ruby-lang.org/