From: "gregolsen (Innokenty Mikhailov)" Date: 2012-03-21T22:24:41+09:00 Subject: [ruby-core:43529] [ruby-trunk - Bug #6183][Open] Enumerator::Lazy performance issue Issue #6183 has been reported by gregolsen (Innokenty Mikhailov). ---------------------------------------- Bug #6183: Enumerator::Lazy performance issue https://bugs.ruby-lang.org/issues/6183 Author: gregolsen (Innokenty Mikhailov) Status: Open Priority: Normal Assignee: Category: Target version: ruby -v: ruby 2.0.0dev (2012-03-17 trunk 35075) [x86_64-linux] I benchmarked Enumerator::Lazy and that's what I got: user system total real Lazy: 0.690000 0.010000 0.700000 ( 0.733160) Normal: 0.160000 0.010000 0.170000 ( 0.186695) It seems like even with 4 chain links and 3000 elements in initial array, Lazy enumerator is almost 4(!) times slower than the normal case. Instead of performance benefit we've got 4 times performance drawback. See test file attached. -- http://bugs.ruby-lang.org/