From: trans <transfire@...>
Date: 2009-03-09T12:07:10+09:00
Subject: Re: Where's the best version of Hash#pass and Hash#block?



On Mar 8, 9:48 pm, Phlip <phlip2...@gmail.com> wrote:
> Rubies:
>
> This snippet shows how to pass or block arbitrary subsets of Hashes, by their keys:
>
>    http://snippets.dzone.com/posts/show/2178
>
> Those items seem useful, because Hashes are not as set-theoretic as Arrays. I
> suspect, for example, one cannot & two Hashes to extract their intersection.
>
> That post is from 2006 - essentially the Neolithic Era!
>
> Where's the best modern version of those methods?

From Facets:

  def slice(*keep_keys)
      h = {}
      keep_keys.each do |key|
        h[key] = fetch(key)
      end
      h
    end

  def except(*less_keys)
    slice(*keys - less_keys)
  end


T.