From: "Aleksi Niemelä" <aleksi.niemela@...>
Date: 2000-11-07T13:14:02+09:00
Subject: [ruby-talk:6097] Re: detect:ifNone: in Ruby

matz queries:
> If we can find better name, 

How about default, defaults or defaulting (I like the last).

Here's an example to evaluate:

  class Object
    def defaulting(expr=nil)
      self
    end
  end

  def nil.defaulting(expr=nil)
    if iterator?
      yield
    else
      expr
    end
  end

  a = [1,2,3,4,5]
  x = a.detect {|i| i == 7} .defaulting 99        #=> 99
  x = a.detect {|i| i == 3} .defaulting 99        #=> 3
  x = a.detect {|i| i == 7} .defaulting { 99 }    #=> 99
  x = a.detect {|i| i == 3} .defaulting { 99 }    #=> 3

  class Summarizer
    def matching_sum(sum)
      @summary.detect {|item| item.name == sum.name}.defaulting {
        result = Sum.new( sum.name, 0)
        @summary << result
        result      
      }
    end
  end

> I agree to add the method to the next version.

I guess we have already couple of features pending to the next version. How
about grouping these into 1.7, letting people play with them, and then
deciding whether they should be included.

Dave says:
> I guess that if the block form isn't important we _could_ just use
> 'or'...

Well, we can use some variant of block form even with 'or'. But as I noted
earlier, it's kind of ugly (gives me perlish feelings).

	- Aleksi