From: Robert Klemme <shortcutter@...>
Date: 2008-01-29T22:50:23+09:00
Subject: Re: Proposal/RFQ: Hash#values/keys with block

2008/1/29, Thomas Wieczorek <wieczo.yo@googlemail.com>:
> On Jan 29, 2008 2:10 PM, Dirk Traulsen <dirk.traulsen@lypso.de> wrote:
> > hash.keys {|k,v| k.size == 1 }      #=> ["a", "c"]
>
> Same here:
> hash.keys.select {|el| el.size == 1 }

Additional note: If selection needs to be done on key and value you can do this:

hash.select {|k,v| k.size == 1 }.map {|k,v| k}

or

irb(main):006:0> hash.inject([]) {|ks,(k,v)| ks << k if k.size == 1; ks}
=> ["a", "c"]

> > Well, I would prefer the extension of Hash#keys/values with blocks.
> > What do you think?

I am waiting to see whether this is generally needed.  As far as I
remember this has not been suggested before.  If there is no
overwhelming request for this I opt for not making this standard.

Kind regards

robert

-- 
use.inject do |as, often| as.you_can - without end