From: Trans <transfire@...>
Date: 2006-07-23T23:15:10+09:00
Subject: Re: Symbols vs. strings as hash_keys - interchangeable or not?


Sean O'Halpin wrote:
> On 7/22/06, transfire@gmail.com <transfire@gmail.com> wrote:
> > As Ezra points out they are not the same in Ruby. A hash key can be any
> > object whatsoever. It could even be a number or another hash:
> >
> >   { {:a=>1} => 'yep' }
> >
> Not meaning to be picky ;) but your example is a bit misleading. Consider:
>
> h1 = { {:a => 1} => 'nope'}
> p h1[{:a => 1}]
> #=> nil
> hk = {:a => 1}
> h2 = {hk => 'yep'}
> p h2[hk]
> #=> "yep"
>
> The problems of using hashes as keys has come up a few times - see
> e.g. ruby-talk:167185 for one solution. Or you could just use:

Huh? I didn't know that. Why isn't one hash "eql?" to another that has
"eql?" elements?

T.