From: erik@... Date: 2020-07-29T15:18:56+00:00 Subject: [ruby-core:99390] [Ruby master Bug#17058] Array#delete_if doesn't change array instantly Issue #17058 has been reported by erik_schlyter (Erik Schlyter). ---------------------------------------- Bug #17058: Array#delete_if doesn't change array instantly https://bugs.ruby-lang.org/issues/17058 * Author: erik_schlyter (Erik Schlyter) * Status: Open * Priority: Normal * ruby -v: ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-linux] * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- According to the documentation: https://ruby-doc.org/core-2.7.1/Array.html#method-i-delete_if "The array is changed instantly every time the block is called, not after the iteration is over." I've tried printing the array while iterating it: ``` a = [1,2,3,4,5,6,7] a.delete_if{|x| puts "During iteration: #{a}" x % 2 == 0 } puts "After iteration: #{a}" ``` The output is as follows: ``` During iteration: [1, 2, 3, 4, 5, 6, 7] During iteration: [1, 2, 3, 4, 5, 6, 7] During iteration: [1, 2, 3, 4, 5, 6, 7] During iteration: [1, 3, 3, 4, 5, 6, 7] During iteration: [1, 3, 3, 4, 5, 6, 7] During iteration: [1, 3, 5, 4, 5, 6, 7] During iteration: [1, 3, 5, 4, 5, 6, 7] After iteration: [1, 3, 5, 7] ``` This functionality has changed somewhere between 2.2.2 and 2.4.0. When I use "ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-linux]", I get the following (correct) output: ``` During iteration: [1, 2, 3, 4, 5, 6, 7] During iteration: [1, 2, 3, 4, 5, 6, 7] During iteration: [1, 3, 4, 5, 6, 7] During iteration: [1, 3, 4, 5, 6, 7] During iteration: [1, 3, 5, 6, 7] During iteration: [1, 3, 5, 6, 7] During iteration: [1, 3, 5, 7] After iteration: [1, 3, 5, 7] ``` When I use "ruby 2.4.0p0 (2016-12-24 revision 57164) [x86_64-linux]" or the latest (2.7.1), I get the wrong output. The functionality doesn't seem crucial, but the documentation should be correct. -- https://bugs.ruby-lang.org/ Unsubscribe: