From: "David A. Black" <dblack@...>
Date: 2008-09-13T08:37:52+09:00
Subject: Re: Advanced conditionals

Hi --

On Sat, 13 Sep 2008, Bill Kelly wrote:

>
> From: "David A. Black" <dblack@rubypal.com>
>> 
>> [...] but you cannot, any longer, do this:
>> 
>> irb(main):007:0> a = [1,2,3,4]
>> => [1, 2, 3, 4]
>> irb(main):008:0> e = a.enum_for(:map, &lambda {|x| x * 10 })
>> => #<Enumerable::Enumerator:0x3d7444>
>> irb(main):009:0> e.next
>> => 10
>> 
>> You'll get 1 now, rather than 10. I'm still very puzzled by the
>> removal of this capability.
>
> Maybe worth asking on ruby-core?  Still 13 days till the
> feature freeze...!

I did. Shugo did discuss it some, but I'm afraid I still didn't
understand, or maybe I just wasn't convinced. I think it probably
boils down to efficiency, though it seems to me to be an example of
something so powerful and potentially useful that efficiency wouldn't
(up to a point) be a deal-breaker.


David

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