From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2012-09-11T19:51:38+09:00
Subject: Re: hand over block to a submethod

On Tue, Sep 11, 2012 at 12:31 PM, bernhard stoecker
<lists@ruby-forum.com> wrote:
> hi @ all,
>
> lets assume I have two methods in class Func
>
> class Func
>
>   def self.mean(array)
>     return 0 if(array.size == 0)
>     if(block_given?)
>       return array.map{|x| yield(x)}.sum.to_f / array.size
>     end
>     return array.sum.to_f / array.size
>   end
>
>
>
>   def self.variance(array)
>     return 0 if array.size == 0
>     avr = Func.mean(array) #HOW TO HAND OVER A BLOCK???
>
>     if(block_given?)
>       return array.map { |i| (yield(i) - avr)**2 }.sum / array.size
>     end
>     return self.map { |i| (i - avr)**2 }.sum / self.size
>
>   end
>
> end
>
>
> my problem is, that i have to hand over the block given to variance to
> the mean method. is this possible and if yes how?
>
> thanks in advance
>
> greets bernhard
>
> --
> Posted via http://www.ruby-forum.com/.
>

1.9.2p290 :001 > def test
1.9.2p290 :002?>   if block_given?
1.9.2p290 :003?>     puts "I have a block"
1.9.2p290 :004?>     yield
1.9.2p290 :005?>     else
1.9.2p290 :006 >       puts "no block"
1.9.2p290 :007?>     end
1.9.2p290 :008?>   end
 => nil
1.9.2p290 :011 > def other &blk
1.9.2p290 :012?>   puts "passing block"
1.9.2p290 :013?>   test &blk
1.9.2p290 :014?>   end
 => nil
1.9.2p290 :015 > other
passing block
no block
 => nil
1.9.2p290 :018 > other {puts "I'm the block"}
passing block
I have a block
I'm the block
 => nil

Jesus.