From: Logan Capaldo <logancapaldo@...>
Date: 2006-03-15T02:27:18+09:00
Subject: Re: Writing Good #each Methods?

--Apple-Mail-4-841261084
Content-Transfer-Encoding: 7bit
Content-Type: text/plain;
	charset=US-ASCII;
	delsp=yes;
	format=flowed


On Mar 14, 2006, at 4:05 AM, Paul Battley wrote:

> I'd also add
> * If appropriate, inspect the arity of the block and provide the
> requested number of parameters.
>
> Hash#each's behaviour is a good example:
> hash = {:a=>1, :b=>2}
> hash.each { |x| p x }
> # [:b, 2]
> # [:a, 1]
> hash.each { |k,v| puts "#{k.inspect} => #{v.inspect}" }
> # :b => 2
> # :a => 1
>
> Paul.

This isn't really a function of Hash#each being smart...

irb(main):001:0> def example()
irb(main):002:1>   yield [:a, 1]
irb(main):003:1> end
=> nil
irb(main):004:0> example { |x| p x }
[:a, 1]
=> nil
irb(main):005:0> example { |k, v| p k; p v; }
:a
1
=> nil

As you can see yielding an array automatically gets you this kind of  
behavior. There are downsides of course...
--Apple-Mail-4-841261084--