From: ts <decoux@...>
Date: 2001-07-15T16:54:05+09:00
Subject: [ruby-talk:17873] Re: Overloaded methods

>>>>> "H" == HarryO  <harryo@zipworld.com.au> writes:

H> I was reading last night about perl's multimethods module and thought it
H> would be interesting to see if that approach was do-able in Ruby.

 The approach of the P language is weird (bad syntax for me) and *slow*. 

 If you really want to look at multi-methods, look at dylan or parasitic
method of j*v*

 Just an example (it's important to see that next_method is a private
 method) 


pigeon% cat b.rb
#!./ruby
class AA < Array
end

class A
   def tt(Array a)
      yield "Array"
      next_method
   end
   def tt(AA a)
      yield "AA"
      next_method
   end
   def tt(String a)
      yield "String"
      next_method
   end

   private
   def tt(Enumerable a)
      yield "Enumerable"
   end

end

p A.instance_methods
p A.private_instance_methods
a = A.new
a.tt(AA.new 1, 2) {|i| puts "received #{i}" }
a.tt("string") {|i| puts "received #{i}" }
a.tt(1 .. 2)
pigeon% 

pigeon% b.rb
["tt"]
["next_method", "tt"]
received AA
received Array
received Enumerable
received String
received Enumerable
./b.rb:31: private method `tt' called for #<A:0x401a5ba4> (NameError)
pigeon% 



Guy Decoux