From: "duerst (Martin Dürst)" Date: 2013-04-05T13:21:43+09:00 Subject: [ruby-dev:47226] [ruby-trunk - Feature #7877] E::Lazy#with_index needed Issue #7877 has been updated by duerst (Martin Dürst). zzak (Zachary Scott) wrote: > Propose to move this to next major? Do you mean because of "potential incompatibility" (https://bugs.ruby-lang.org/issues/7877#note-4)? What exactly would this incompatibility be? To me, it seems that lazy.with_index would just work, so we should just fix it. Next major seems way too long to wait. ---------------------------------------- Feature #7877: E::Lazy#with_index needed https://bugs.ruby-lang.org/issues/7877#change-38252 Author: shyouhei (Shyouhei Urabe) Status: Assigned Priority: Normal Assignee: yhara (Yutaka HARA) Category: core Target version: next minor =begin So I wanted some real benefit of being lazy. I wrote a Leibniz formula: def leibniz(n) (0..Float::INFINITY).lazy.with_index {|i, j| (-1 ** j) / (2*i+1).to_f }.take(n).reduce(:+) end But it doesn't work (well, it does, indeed. It just doesn't stop working). I got frustrated. How about it? Don't you feel it nifty? Of course I can wait for the release next to 2.0.0. =end -- http://bugs.ruby-lang.org/