From: Robert Klemme <shortcutter@...>
Date: 2006-06-26T18:40:14+09:00
Subject: Re: << for Hash?

2006/6/26, Simon Baird <simon.baird@gmail.com>:
> class Hash
>   def <<(arg)
>     self.merge!(arg)
>   end
> end
>
> Eg,
>
> thing = {
>   :foo => 1,
> }
>
> thing << {
>   :bar => 2,
>    :baz => 3,
> }
>
> thing #=> {:foo=>1, :bar=>2, :baz=>3 }
>
>
> Of course it overwrites existing keys. I think it's a little sexier than
>
> thing.merge!({
>    :bar => 2,
>    :baz => 3,
> })
>
> or
>  thing[:bar] = 1
> thing[:baz] = 3
>
>
> Is it safe to use this? Is there some good reason why << is not already
> defined for Hash?

The reason is probably that your << appends a complete collection (a
hash) to the hash while usually it appends just a single element (see
for example Array#<< and IO#<<). While I think about it, String#<<
appends the same type (String) to a String...

Kind regards

robert

-- 
Have a look: http://www.flickr.com/photos/fussel-foto/