From: "tompng (tomoya ishida) via ruby-core" <ruby-core@...>
Date: 2025-06-23T13:23:40+00:00
Subject: [ruby-core:122581] [Ruby Bug#21449] Set#divide is order dependent and not working correctly

Issue #21449 has been updated by tompng (tomoya ishida).


pull request https://github.com/ruby/ruby/pull/13680

----------------------------------------
Bug #21449: Set#divide is order dependent and not working correctly
https://bugs.ruby-lang.org/issues/21449#change-113814

* Author: tompng (tomoya ishida)
* Status: Open
* ruby -v: ruby 3.5.0dev (2025-06-23T11:03:48Z master af6b98f7a2) +YJIT +MN +PRISM [arm64-darwin22]
* Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN
----------------------------------------
~~~ruby
Set[0,1,2,3].divide{(_1 - _2).abs == 1}
#=> #<Set: {#<Set: {0, 1, 2, 3}>}>

Set[0,2,3,1].divide{(_1 - _2).abs == 1}
#=> #<Set: {#<Set: {0, 1, 2, 3}>}> (ruby 3.4)
#=> #<Set: {#<Set: {0, 1}>, #<Set: {2, 3, 1}>}> (ruby 3.5.0dev)
~~~

Result of `Set#divide` wrongly depends on set order.
~~~ruby
Set.new(1000.times.to_a.shuffle).divide{(_1 - _2).abs == 1}.size
#=> 1 (ruby 3.4)
#=> 250�20 (ruby 3.5.0dev)
~~~




-- 
https://bugs.ruby-lang.org/
______________________________________________
 ruby-core mailing list -- ruby-core@ml.ruby-lang.org
 To unsubscribe send an email to ruby-core-leave@ml.ruby-lang.org
 ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/