From: Ruby-Lang@... Date: 2018-01-07T01:55:42+00:00 Subject: [ruby-core:84680] [Ruby trunk Bug#14069] Document order of elements in Set Issue #14069 has been updated by jwmittag (J��rg W Mittag). *Is* that actually guaranteed by the specification? Can you point to any specification or documentation or official statement by the core team that supports your assertion that sets are insertion-ordered? ---------------------------------------- Bug #14069: Document order of elements in Set https://bugs.ruby-lang.org/issues/14069#change-69394 * Author: abotalov (Andrei Botalov) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: 2.4 * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN ---------------------------------------- Hash enumerates values in the insertion order. Set is built on Hash so it does the same. However, this is currently believed to be a not documented implementation detail. See: https://stackoverflow.com/a/14468621/841064 https://stackoverflow.com/questions/10361250/does-set-in-ruby-always-preserve-insertion-order#comment13351258_10361275 https://spin.atomicobject.com/2012/09/04/when-is-a-set-better-than-an-array-in-ruby/ I think it would be better to explicitly document that Set class enumerates keys in the insertion order. -- https://bugs.ruby-lang.org/ Unsubscribe: