From: marcandre-ruby-core@... Date: 2020-08-27T02:10:00+00:00 Subject: [ruby-core:99722] [Ruby master Bug#17030] Enumerable#grep{_v} should be optimized for Regexp Issue #17030 has been updated by marcandre (Marc-Andre Lafortune). Dan0042 (Daniel DeLorme) wrote in #note-17: > Maybe not impossible, but personally I wouldn't want to code that kind of analysis when a simple approach is enough for >90% of cases, and guaranteed to be bug-free. Agreed > > There will be other false positives: `str.gsub(regexp, &block)`. That's not a real issue, simply assume that `block` will want access to `Regexp.last_match`. > > Actually... `block` does not have access to `Regexp.last_match` (unless you created the block in the same scope as the gsub operation, but that would be unusual) You are right, my bad. ---------------------------------------- Bug #17030: Enumerable#grep{_v} should be optimized for Regexp https://bugs.ruby-lang.org/issues/17030#change-87213 * Author: marcandre (Marc-Andre Lafortune) * Status: Open * Priority: Normal * Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN ---------------------------------------- Currently, ```ruby array.select { |e| e.match?(REGEXP) } ``` is about three times faster and six times more memory efficient than ```ruby array.grep(REGEXP) ``` This is because `grep` calls `Regexp#===`, which creates useless `MatchData`. -- https://bugs.ruby-lang.org/ Unsubscribe: