From: William James <w_a_x_man@...>
Date: 2007-01-22T05:45:08+09:00
Subject: Re: Hash pairs at?

dblack@wobblini.net wrote:
> Hi --
>
> On Mon, 22 Jan 2007, Phrogz wrote:
>
> > Phrogz wrote:
> >> Trans wrote:
> >>> Seems like there should be a mehtod for this:
> >> class Hash
> >>   def entries( *keys )
> >>     self.class[ *keys.zip( values_at( *keys ) ).flatten ]
> >>   end
> >> end
> >
> > Oh, and yes: I'd like a method like this in the core, also. Preferably
> > with a more elegant, faster implementation than the above. I find this
> > quite useful sometimes. A recent example that comes to mind is taking
> > the params hash in Rails and specifying a specific subset of the
> > populated values to pass on to another method.
>
> I'll put in a plug here for flattenx, which lets you flatten by any
> number of levels so that you could do the above without the
> over-flattening vulnerability.
>
> http://raa.ruby-lang.org/project/flattenx/

class Array
  def flatten_1
    inject([]){|a,x| Array(x).each{|e| a<<e}; a}
  end
end

p [[[[22],33],44], %w(aa bb cc), [88,[99,55]], 3.14].flatten_1

---  output  -----
[[[22], 33], 44, "aa", "bb", "cc", 88, [99, 55], 3.14]