From: Luke Kanies <luke@...>
Date: 2007-01-17T08:26:20+09:00
Subject: Solutions for deep class paths

Hi all,

I've currently got a very flat code structure in a large code base 
[1], and I'm looking at redoing the layout to make the functional  
lines more obvious.  This redesign will add an extra constant to  
every class path; e.g., where I might have 'Puppet::Type::User' right  
now, I'd have 'Puppet::OSAL::Type::User' in the new layout.

If possible, I'd like to avoid having to type full class paths every  
time I talk about a class.  I've noticed that Ruby behaves very  
differently depending on how I define a class; for instance:

class One
   class Two
   end
end

will allow Two to use unqualified constants from One, but

class One::Two
end

will not.  This is fine for shallow class paths, but it gets annoying  
when every single class I define has to look like this:

module Puppet
   module OSAL
     class Type
       class User
       ...
       end
     end
   end
end

I'd *much* prefer to just write:

module Puppet::OSAL::Type::User
end

But if I do that, then I'll always have to specify the full class  
path.  I have quite a few classes in Puppet, and having to include  
the full wrappers for every constant in the class path would get very  
painful, and I would have to be very conscious of load order (because  
every class in Puppet::OSAL::Type would either have to specify type's  
parent class if there is one, or it would have to be loaded after  
Puppet::OSAL::Type was loaded).

Are there semi-standard ways of making deep class paths more  
convenient to use?

Thanks,
Luke

1 - http://reductivelabs.com/projects/puppet

  --
  Someday I want to be rich. Some people get so rich they lose all
  respect for humanity. That's how rich I want to be.  --Rita Rudner
  ---------------------------------------------------------------------
  Luke Kanies | http://reductivelabs.com | http://madstop.com