From: "trans (Thomas Sawyer)" Date: 2012-03-21T23:33:23+09:00 Subject: [ruby-core:43536] [ruby-trunk - Bug #6183] Enumerator::Lazy performance issue Issue #6183 has been updated by trans (Thomas Sawyer). Granted that seems like a bit too much overhead, but the advantage to lazy is not in a 1-to-1 comparison with non-lazy. Try removing the `.each` call at the end and adding `.take(10)` instead. ---------------------------------------- Bug #6183: Enumerator::Lazy performance issue https://bugs.ruby-lang.org/issues/6183#change-25016 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/