From: Kristof Bastiaensen <kristof@...>
Date: 2004-05-19T20:38:56+09:00
Subject: Re: RCR: More enumerator functionality

On Wed, 19 May 2004 11:47:30 +0900, nobu.nokada wrote:
>> 5.enum_filter(:times){ |i| i[0] == 0 }.collect
>> => [2, 4]
>   => [0, 2, 4]
> 
> Isn't it?
> 

Oh, yes, of course.  (stupid mistake)

>> (2)* Enumerable::Enumerator takes a optional block
>> 
>> powers = 4.enum_for(:times){ |i| i * i  }
>> powers.collect 
>> => [0, 1, 4, 9]
> 
> I tried the implementation of these two experimentally.  But I
> feel enum_filter is overdoing after all.
> 
> This patch provides block for Enumerable#enum_for and
> Enumerable#enum_if instead.

Yes, that's cleaner.  I like the naming also.

> 
>   $ ./ruby -renumerator -e 'p 5.enum_for(:times){|i| i*i}.to_a'
>   [0, 1, 4, 9, 16]
>   $ ./ruby -renumerator -e 'p 5.enum_for(:times).enum_if{|i| i[0] == 0}.to_a'
>   [0, 2, 4]
> 
> Just my 2 yens.
> 
Great!

Thanks,
Kristof