From: Nikolay Pavlov <qpadla@...>
Date: 2007-09-12T05:19:47+09:00
Subject: Re: alter_key function for Hash

On Tuesday 11 September 2007 21:14:43 Daniel Schierbeck wrote:
> On Wed, 2007-09-12 at 02:57 +0900, Nikolay Pavlov wrote:
> > Hallo all.
> > Of course i am reinventing the wheel, but may be that would be helpful
> > for some one. With this method you can replace a key with a new one in
> > a Hash. It could be helpful for example if you want to parse a lot of
> > XML documents in hash from various external sources in one Library, so
> > that you can handle a unified interface.
> >
> > class Hash
> >
> >   # Replace an old key with a new one
> >   #
> >   # === Arguments:
> >   # * old_key
> >   # * new_key
> >   def alter_key(old_key, new_key)
> >     raise IndexError.new("key already exist") if self[new_key]
> >     if self.has_key?(old_key)
> >       self[new_key] = self[old_key]
> >       self.delete(old_key)
> >     end
> >     return self
> >   end
> > end
>
> It can even be written more concisely as:
>
>   class Hash
>     def alter_key(old_key, new_key)
>       raise IndexError, 'key already exists' if has_key? new_key
>       store(new_key, delete(old_key)) if has_key? old_key
>       return self
>     end
>   end
>
>
> Cheers,
> Daniel Schierbeck

Thanks Danial.
This is just a wheel :)

-- 
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- Best regards, Nikolay Pavlov. <<<-----------------------------------    
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