From: "Peña, Botp" <botp@...>
Date: 2008-08-15T15:56:01+09:00
Subject: Re: Use of dup to remove references

From: Brian Ross [mailto:p.brian.ross@gmail.com] 
# def wipe_from( sentence )
#   sentence_new = sentence

if in doubt, insert

    p sentence.object_id
    p sentence_new.object_id


#   while sentence_new.include? '('
#     open = sentence_new.index( '(' )
#     close = sentence_new.index( ')', open )
#     sentence_new[open..close] = '' if close
#   end
# sentence_new
# end
# spoken = "I'm not happy with (nonsense) this moon."
# test = wipe_from( spoken )
# puts spoken
# puts test

if in doubt, insert

    p spoken.object_id
    p test.object_id
 
# # End of code
# 
# I'd expect that the variable spoken would be unchanged because it's
# sentence_new that's being modified. It works as expected if I 

variables are just references to objects. when you do

   y = "test"
   x = y

x and y now references to the original string object "test"

# use dup or clone, but why is spoken being modified at all? 
# Shouldn't it just be returning the value of sentence_new?

not ruby. use dup or clone to taste :)

anyway, in ruby nothing is impossible. In fact, there are many better ways ;)

in your case eg, you can use string#gsub

sample,

irb(main):001:0> spoken = "I'm not happy with (nonsense) this moon."
=> "I'm not happy with (nonsense) this moon."

irb(main):002:0> spoken_new = spoken.gsub(/\(.*\)/,"")
=> "I'm not happy with  this moon."

irb(main):003:0> spoken_new
=> "I'm not happy with  this moon."

irb(main):004:0> spoken
=> "I'm not happy with (nonsense) this moon."

hth.
kind regards -botp