From: ruby-core@... Date: 2018-07-21T22:37:57+00:00 Subject: [ruby-core:88043] [Ruby trunk Bug#14926] Different results between Enumerable#sum and #reduce when Float::INFINITY present Issue #14926 has been updated by marcandre (Marc-Andre Lafortune). Yes, definitely a bug in the algorithm trying to minimize floating errors. Result must be `Float::INFINITY`. shevegen (Robert A. Heiler) wrote: > I am a bit surprised about infinity though: > > a = [Float::INFINITY].reduce(0, &:+) > b = [Float::INFINITY] > > puts (a == b) # => false Using `p` instead of `puts` will show you you are comparing an array with float... > p a # => Infinity > p b # => [Infinity] ---------------------------------------- Bug #14926: Different results between Enumerable#sum and #reduce when Float::INFINITY present https://bugs.ruby-lang.org/issues/14926#change-73060 * Author: swistak35 (Rafa�� ��asocha) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-linux] * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- When `Float::INFINITY` is present in array, `Enumerable#sum` and `Enumerable#reduce(0, &:+)` are giving different results. ``` puts [Float::INFINITY].sum puts [Float::INFINITY].reduce(0, &:+) ``` results in ``` NaN Infinity ``` And I would expect both of them to be `Infinity` (meaning: `#sum` is working incorrectly). Checked on `ruby 2.5.1p57` and `ruby 2.4.3p205`, both have the same bug. -- https://bugs.ruby-lang.org/ Unsubscribe: