From: dblack@...
Date: 2002-08-09T01:55:09+09:00
Subject: Enumerable#any? (was: Re: Coding challenge (on Ruby Garden) [long])

Hi --

On Thu, 8 Aug 2002, Christoph wrote:

>
> "Bill Kelly" <billk@cts.com> wrote in message
> news:002901c23e70$402b3d30$fa7b1b42@musicbox...
> > Hi,
> >
> > > Hm, maybe you want to benchmark my solution, Chr0002, as well?
> >
> > Whoops, I don't seem to have Array#any? and Array#all?.  :)  New
> > methods in 1.7 I guess?
>
> Yup, they are a generalization of  && and || to Enumerables.
>
> module Enumerable
>     def all?
>         each {|e| return false unless yield e }
>         return true
>     end
>     def any?
>         each {|e| return true if  yield e }
>          return false
>     end
> end

At first glance I thought that #any? didn't add anything to just using
the Boolean value of the result of #detect... until I tried this:

  ar = [1,2,3,nil,5]
  puts "nil found by any?" if ar.any? {|e| e == nil }
  puts "nil found by detect" if ar.detect {|e| e == nil}

:-)


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav