Issue #8948 has been updated by Eregon (Benoit Daloze). @matz Is it OK to merge https://github.com/ruby/ruby/pull/14547 now for 4.1? Then there is plenty of time for the few gems that rely on mutable Regexp to adapt. BTW I noticed someone else also did a PR for this, so there seems to be some interest: https://github.com/ruby/ruby/pull/15762 ---------------------------------------- Feature #8948: Frozen regex https://bugs.ruby-lang.org/issues/8948#change-115919 * Author: sawa (Tsuyoshi Sawada) * Status: Assigned * Assignee: Eregon (Benoit Daloze) * Target version: 4.1 ---------------------------------------- =begin I see that frozen string was accepted for Ruby 2.1, and frozen array and hash are proposed in https://bugs.ruby-lang.org/issues/8909. I feel there is even more use case for a frozen regex, i.e., a regex literal that generates a regex only once. It is frequent to have a regex within a frequently repeated portion of code, and generating the same regex each time is a waste of resource. At the moment, we can have a code like: class Foo RE1 = /pattern1/ RE2 = /pattern1/ RE3 = /pattern1/ def classify case self when RE1 then 1 when RE2 then 2 when RE3 then 3 else 4 end end end but suppose we have a frozen `Regexp` literal `//f`. Then we can write like: class Foo def classify case self when /pattern1/f then 1 when /pattern1/f then 2 when /pattern1/f then 3 else 4 end end end =end -- https://bugs.ruby-lang.org/