From: Gavin Sinclair <gsinclair@...>
Date: 2003-01-02T23:04:47+09:00
Subject: Re: ENV.clear

On Friday, January 3, 2003, 12:49:27 AM, TOTO wrote:

> The update method will return a copy of the new Hash or a copy of the
> reference of the new Hash? How did you find out? I couldn't find it in
> the Ruby reference.

'ri' - the Ruby programmer's friend.  You need it. :)  It's a
destructive method.  Look for 'ri' in the RAA.

> To be honest, I have a stupid thought originally, before I know I can
> use update method. I think I should implement an insert method for
> class Hash to do the same thing. And then I find that it might be
> impossible to do it with Ruby itself, because the class Hash is
> implemented in c.

Nothing is impossible.  You can add methods to the Hash class.
Generally the method you add will be implemented in terms of the
existing methods.  If #update didn't exist, you could add it thus
(untested):

  class Hash
    def update(other)
      other.each do |key, value|
        self[key] = value
      end
    end
  end

Gavin