From: Yusuke Endoh <mame@...>
Date: 2012-04-04T20:59:19+09:00
Subject: [ruby-core:44125] Re: [ruby-trunk - Bug #6183] Enumerator::Lazy performance issue

Hello,

2012/4/4 gregolsen (Innokenty Mikhailov) <anotheroneman@yahoo.com>:
> Here's the new patch attached - problem, mentioned by Yusuke Endoh, fixed - now I'm creating a new copy of enumerator on each lazy method call.

Okay, the next problem :-)

  (1..10).lazy.select {|x| false }.map {|x| p x }.to_a

should print nothing, but it actually prints 1, 2, ..., 10
with your patch applied.  It can be fixed easily, though.


I glanced your patch.  It will degrade functional modularity
in enumerator.c.  Currently, it not so big problem because
it only implements #map and #select.  But I guess implementing
other methods, especially, #cycle and #zip, will make some
functions (process_element and lazy_iterator_block) complex
and hard to maintain.

Thus, until you create the final patch, it is hard to say
whether we can import your patch or not.

-- 
Yusuke Endoh <mame@tsg.ne.jp>