From: Matthias Reitinger <reitinge@...>
Date: 2009-03-09T16:59:29+09:00
Subject: Re: Where's the best version of Hash#pass and Hash#block?

Phlip wrote:
>>   def slice(*keep_keys)
> 
> It's okay, but...
> 
> If I already have an array, I have to splat * it in:
> 
>    my_hash.slice(*array)
> 
> Why doesn't slice do the flatten trick here?
> 
>      keep_keys = [keep_keys].flatten

It would lead to ambiguities if you additionally allowed passing an 
array of keys.  Consider:

  hsh = { [:one, :two] => [1, 2], :one => 1, :two => 2 }
  hsh.slice([:one, :two])

Now what should the last line yield?  Both { :one => 1, :two => 2 } and 
{ [:one, :two] => [1, 2] } would be valid, depending on how you 
interpret [:one, :two] (array of keys vs. single key).

-Matthias
-- 
Posted via http://www.ruby-forum.com/.