From: Robert Klemme <bob.news@...>
Date: 2006-01-02T22:22:57+09:00
Subject: Re: About blocks

Surgeon <biyokuantum@gmail.com> wrote:
> Hi,
>
> (This question might be answered previously. If so, I apologize.)
>
> Can we *ALWAYS* use plain methods instead of blocks? Yes, sometimes
> using a block may be obviously better than using a method but I mean,
> are there any situations in which the *ONLY* solution is to use a
> block rather than a method? May someone be forced to use only and
> only a block? I ask this because I am not very intelligent and I am
> not sure that I will thoroughly understand the "block" concept.

You need blocks everywhere you need an anonymous callback function such as 
with iterations:

an_array.each {|e| ... }

And you need lambdas (i.e. blocks converted to an object) if you need to 
store the thing in a variable:

class SortedArray < Array
  attr_accessor :comparator
  def each
    sort!(&comparator)
    super(&b)
  end
end

Does that help?

Kind regards

    robert