From: ts <decoux@...>
Date: 2003-07-07T19:54:29+09:00
Subject: Re: Help with UnboundMethod#bind error

>>>>> "M" == Mauricio =?iso-8859-1?Q?Fern=E1ndez?= <Mauricio> writes:

M> The extension is easy to write (although you'll have to wait for Guy to
M> check if my code is a time bomb :-):

 Well, I've sent in a private email the extension to "Pit Capitain".

 For me it has some problems :

  1) you must know where a method is defined when you call ::override

  2) it work actually for Class and not Module, it's easy to change it but
     you'll have the same problem than in [ruby-talk:72510]

 Imagine that you want to intercept the method #each for all Enumerable :
 instinctively you write

   module Enumerable
      overrive :each
      def each
         puts "before each"
         super
      end
   end

 Then you write

   [1, 2].each {|i| p i}

 and you'll see that it don't work because Array has defined #each

 You don't have these problems the way that matz do it, because you just
 write 

svg% cat b.rb
#!./ruby
module Enumerable
   def each:before
      puts "before each"
   end
end

[1, 2].each {|i| p i }
{"a" => 1, "b" => 2}.each {|*i| p i }
(1..2).each {|i| p i }
svg% 

svg% b.rb
before each
1
2
before each
["a", 1]
["b", 2]
before each
1
2
svg% 

 You just need to know the relation that it exist between classes (or
 classes and modules) and you have this information. Rather than know where
 a method is defined (information that you don't have fatally).


Guy Decoux