From: "Brian Schröder" <ruby.brian@...>
Date: 2005-08-26T21:17:26+09:00
Subject: Re: Circular dependecy on classes

On 26/08/05, Anatol Pomozov <anatol.pomozov@gmail.com> wrote:
> I have several classes that have circular dependencies on each other.
> See following example.
> 
> class Solder
>   @can_upgrade_to = [Knight]
>   #or use constant from Knight class
> 
>   def upgrade!(to)
>     raise "Unable to upgrade" unless @can_upgrade_to.contain(to)
>   end
> end
> 
> class Knight < Solder
> end
> 
> I cant use Knight constant (class name) before Solder and can't use
> Solder before Knight.
> 
> I am just come from Java lang and for Java circular class deps is not
> a problem.
> But ruby is a dynamic language and it creates classes just on script
> executing. (right?)
> 
> So my questions is: how to solve this problem? What is the best way to
> deal with it.
> 
> --
> anatol
> 
> 

You could reopen the class. That works like predeclaration in other languages.

class Soldier
end

class Knight < Soldier  
end

class Soldier
  @can_upgrade_to = [Knight]

  ...
end

regards,

Brian


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