From: Nasir Khan <rubylearner@...>
Date: 2007-01-29T14:41:51+09:00
Subject: perplexing difference between debug and normal run of a simple program

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Please look at this snippet -

--------------------------------
class Test

  def initialize
    @hash = {}
  end

  def method_missing(m,*a)
    if m.to_s =~ /=$/
      Test.class_eval do
        define_method($`.to_sym) do  #accessor
          @hash[$`.to_sym]
        end
        define_method(m) do |arg| #mutator
          @hash[$`.to_sym] = arg.split(",")
        end
      end
      send m, *a
    else
      raise NoMethodError, "#{m}"
    end
  end
end

t = Test.new
t.a = "hello"
puts t.a

-----------------

When I run this from the cmdline I get -
------------------------------------
D:\sandbox\nasir>ruby  test.rb
test.rb:10:in `a': undefined method `to_sym' for nil:NilClass
(NoMethodError)
        from test.rb:25
-----------------------------------

I was unable to debug this so I started  the debugger session but I was
surprised to find that it ran as expected in the debugger session ?????-

--------------------------------
D:\sandbox\nasir>ruby -r debug test.rb
Debug.rb
Emacs support available.

d:/ruby/lib/ruby/site_ruby/1.8/ubygems.rb:10:require 'rubygems'
(rdb:1) c
hello
--------------------------------

First of all can anyone please explain why it runs with debugger while fails
with normal interpreter?

Second what is wrong with the snippet?

Thanks

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