From: Luc Heinrich <luc@...>
Date: 2008-11-18T17:31:53+09:00
Subject: Re: function to select only certain key/value pairs from hash?

On 17 nov. 08, at 23:50, Aryk Grosz wrote:

> hash.from_keys(:a,:b) => {:a=> 1, :b=> 2}

I tried to resist making this a one-liner and went for the clean and  
explicit way :)

class Hash
     def from_keys(*keys)
         selected_values = self.values_at(*keys)
         selected_key_values = keys.zip(selected_values)
         Hash[*selected_key_values.flatten]
     end
end

hash = {:a => 1, :b => 2, :c => 3}
p hash.from_keys(:a, :b)

=> {:a=>1, :b=>2}

-- 
Luc Heinrich - luc@honk-honk.com