From: Simon Strandgaard <0bz63fz3m1qt3001@...>
Date: 2003-07-02T01:50:14+09:00
Subject: Re: Concatenating Hash's

On Wed, 25 Jun 2003 18:10:05 +0200, Robert Klemme wrote:

> 
> "Simon Strandgaard" <0bz63fz3m1qt3001@sneakemail.com> schrieb im
> Newsbeitrag news:pan.2003.06.25.08.56.32.933291@sneakemail.com...
>> On Wed, 25 Jun 2003 10:45:02 +0200, Robert Klemme wrote:
>> >
>> > def hash_join(h1,h2); h1.dup.update(h2); end
>> >
>> > you could also do
>> >
>> > class Hash; def +(o); dup.update(o); end; end
>> >
>> > h1={1,2,3,4}
>> > h2={"a","b"}
>> > h1 + h2  # => {"a"=>"b", 1=>2, 3=>4}
>>
>>
>> If your hash-tables has differents sizes, I suppose that it will be
>> fastest to merge the smallest into the biggest.
> 
> You mean
> 
> class Hash; def +(o); if size >= o.size then dup.update(o); else o+self;
> end; end; end
> 
> ?

Hmm.. 


In Ruby-1.8.0  there is also:  Hash#merge  and  Hash#merge!  

How is Hash#update different from Hash#merge!  are one just an aliases ?

--
Simon Strandgaard