From: Devin Mullins <twifkak@...>
Date: 2005-12-22T13:28:16+09:00
Subject: Re: move to front of array

Payton Swick wrote:

> Hi,
>
> I have an array of Strings, and I'd like to find one of the items by 
> Regexp, then move that item to the front of the array, eg:
>
> array = %w(a B c d Cool e f G)
> array.unshift(array.slice!(array.index(array.find { |i| i =~ /cool/i 
> }))) if array.find { |i| i =~ /cool/i }
>
> Better/cleaner/shorter ways to do it?

I'm going to do something controversial and suggestion a completely 
imperative method:

array.each_with_index {|o,i| array.unshift(array.delete_at(i)) if o =~ 
/cool/i}

Oddly, this works with multiple instances of Cool. I take it that 
#each_with_index doesn't miss a beat wrt the modifications.

Oh, and if you'll be doing it more than once in your code, then put the 
method where it belongs:
class Array
 def bubble_if!(regex=nil)
  if block_given? then each_with_index {|o,i| unshift(delete_at(i)) if 
yield o}
  else super() {|o| =~ regex}
  end
end
end
array.bubble_if!(/cool/i)

Devin
YMMV.