From: duerst@... Date: 2019-10-14T02:02:46+00:00 Subject: [ruby-core:95315] [Ruby master Feature#16146] Array .difference allow custom comparison Issue #16146 has been updated by duerst (Martin D�rst). jonathanhefner (Jonathan Hefner) wrote: > Dan0042 (Daniel DeLorme) wrote: > > What you're asking for is a O(n�) operation. I'm not sure it's a good idea to make that so easy and transparent as a core method. > > Although the given example specified a two-argument block, the original post references `uniq`, which accepts a one-argument block. Using a one-argument block can result in an O(n) implementation. Well, that assumes that the block return values can be ordered. But it's easy to create cases where values can be compared for equality, but not ordered. Example: `[1, 'abc']`. Also, this proposal is about adding a block to `difference`, but if we do that, we should add it to `union` and `intersection` and so on, too. ---------------------------------------- Feature #16146: Array .difference allow custom comparison https://bugs.ruby-lang.org/issues/16146#change-82013 * Author: ngomez (Nancy Gomez) * Status: Open * Priority: Normal * Assignee: * Target version: ---------------------------------------- Hello! I wanted to know if there's any plan to implement the ability to define comparison between individual items in arrays. Here is where I originally asked the question on Stack Overflow: https://stackoverflow.com/questions/57316775/is-there-any-way-to-specify-how-to-compare-of-array-of-objects-for-difference-f But specifically, I noticed nearly all the existing Array functions allow us to define ways for comparison, such as #uniq but #difference does not :( This is quite unfortunate but I'm hoping it's just because this function was introduced in 2.6.0, and hopefully this feature can be implemented? Thanks for any and all info :) -- https://bugs.ruby-lang.org/ Unsubscribe: