From: Stefan Mahlitz <stefan@...>
Date: 2006-01-20T02:47:54+09:00
Subject: Re: Help for upgrading my sources from ruby 1.6.8 to 1.8.x

nobu@ruby-lang.org wrote:
>> 2. question:
>> Because we are developing for railway organizations, we have a 
>> track-element called "Signal". Therefore we have also created a 
>> corresponding class Signal (using it a long time and in many 
>> applications). This is in conflict with ruby 1.8.
>> Do we have any chance to omit the change of the class name to be 
>> compliant with 1.8?
> 
> module Railway
>   class Signal
>   end
> end

But code using

Signal::SomeConstant

will have to be changed to

Railway::Signal::SomeConstant

module Railway
  class Signal
    SomeConstant = "FOO"
  end
end

p Railway::Signal::SomeConstant # prints "FOO"

include Railway

p Signal::SomeConstant
# raises a name error NameError: uninitialized constant
# Signal::SomeConstant

One can do

module Signal
  SomeConstant = Railway::Signal::SomeConstant
end