From: Kent Dahl <kentda@...>
Date: 2003-07-09T19:10:18+09:00
Subject: Re: Accessing code blocks

Grzegorz Dostatni wrote:
> Is it possible for me to access the "text version of block?" Can I print
> out the code that has been attached to my function instead of executing
> it?

As others have pointed out, this is not possible, atleast not without
jumping through hoops. If you don't mind jumping through hoops on the
caller side and a little uglier code, here is a quick stab I did at this
earlier:

class X
  def first_definition( &binding )
    @binding ||= binding
    source = binding.call
    redefine( source )
  end
  def redefine( source )
    @source = source
    @block = eval "Proc.new { #{source} }", @binding
  end
  def x(i)
    @block.call(i)
  end
end
x = X.new
a = 3
x.first_definition { %{|i|a+i} }
puts x.x(2) #=> 5
x.redefine %{|i|a-i}
puts x.x(2) #=> 1

Notice the syntax { %{|i|a+i} }
I wrap a string, "|i|a+i", inside a block. The block at this level only
serves as a binding, the contents of the string is used to create the
block itself. HTH

-- 
(\[ Kent Dahl ]/)_    _~_    _____[ http://www.pvv.org/~kentda/ ]_____/~
 ))\_student_/((  \__d L b__/ (pre-) Master of Science in Technology  )
( \__\_�|�_/__/ ) _)Industrial economics and technological management(
 \____/_�_\____/ (____engineering.discipline_=_Computer::Technology___)