From: sin@... Date: 2020-03-07T00:58:46+00:00 Subject: [ruby-core:97388] [Ruby master Feature#16665] Add an Array#except_index method Issue #16665 has been updated by prajjwal (Prajjwal Singh). In my opinion `omit_indices` is the best name in the thread so far, but I'm not a huge fan of making my methods verbs. I propose `arr.except_indices(1, 2, 3)` as an alternative. The negation of `values_at()` is a semi-common occurrence and I'd love to have it in ruby core. I'll try to throw something together today, it can be trivially renamed whenever matz chimes in. ---------------------------------------- Feature #16665: Add an Array#except_index method https://bugs.ruby-lang.org/issues/16665#change-84518 * Author: alex_golubenko (Alex Golubenko) * Status: Open * Priority: Normal ---------------------------------------- The main idea is to implement a method that we can use to exclude elements from the array by their indices. For example: ``` ruby %w( a b c d e f).except_index(0, -1) => ["b", "c", "d", "e"] %w( a b c d e f g h ).except_index(0..1, 3, -2..-1) => ["c", "e", "f"] ``` I was meeting many questions on the StackOverflow about how to do such functionality also found many topics about it. So I think it might a helpful addition. I spent a few days finding the proper solution on Ruby that might be acceptable with integers and ranges(both positive and negative) and has good performance: ```ruby def except_index(*indexes) indexes.each_with_object(dup) do |ind, obj| ind.is_a?(Range) ? ind.each { |i| obj[i] = false } : obj[ind] = false end.select(&:itself) end ``` As you can see it's have not the best readability so I think it's a good point to add a built-in method on C. -- https://bugs.ruby-lang.org/ Unsubscribe: