From: "David A. Black" <dblack@...>
Date: 2004-07-06T23:04:19+09:00
Subject: Re: Array::index and rindex operator

Hi --

On Tue, 6 Jul 2004, Robert Klemme wrote:

> True.  The approach is betters suited to a method implementation:
> 
> module Enumerable
>   def index_2(obj=nil, &b)
>     b = lambda {|x| obj == x} unless b
>     inject(0) {|i,el| return i if b.call(el); i+1}
>     nil
>   end
> end

I agree.  My version, for what it's worth, was:

  module Enumerable
    def b_index
      each_with_index {|e,i| return i if yield(e) }
      nil
    end
  end

I decided to make it orthogonal to #index, rather than a superset of
it, on the theory that it would be good to avoid making it legal to
give both an argument and a block.  I also like #each_with_index
here, rather than #inject, only because it does more of the work and
eliminates the need for manually incrementing an index.  I haven't
benchmarked them though.


David

-- 
David A. Black
dblack@wobblini.net