From: Trans <transfire@...>
Date: 2008-04-13T08:12:07+09:00
Subject: Re: Hash#slice


On Apr 12, 5:00 pm, ara howard <ara.t.how...@gmail.com> wrote:
> is this consistent with other peoples stdlib hacks?
>
> class Hash
>    def slice *keys, &block
>      if block
>        each do |key, val|
>          boolean = block.call(key, val)
>          keys << key if boolean
>        end
>      end
>      hash = self
>      keys.inject({}){|returned, key| returned.update key => hash[key]}
>    end
> end
>
> ??

Let see.... Facets:

  class Hash

    # Returns a new hash with only the given keys.

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

    # Replaces hash with a new hash having only the given keys.
    # This return the hash of keys removed.

    def slice!(*keep_keys)
      removed = except(*keep_keys)
      replace(slice(*keep_keys))
      removed
    end

  end

T.