From: Intransition <transfire@...>
Date: 2010-12-14T06:33:56+09:00
Subject: Re: VERSION constant issue

On Dec 13, 1:21 pm, Eric Hodel <drbr...@segment7.net> wrote:
> On Nov 25, 2010, at 05:54, Intransition wrote:
>
> > Ruby's VERSION constant is getting in the way of using #const_missing
> > in my module. Here's some example code:
>
> >  module Foo
> >    def self.const_data
> >      @const_data ||= { 'version' => '1.0.0' }
> >    end
>
> >    def self.const_missing(name)
> >      key = name.to_s.downcase
> >      const_data[key] || super(name)
> >    end
> >  end
>
> >  Foo::VERSION  #=> '1.8.7'
>
> > How can I fix this?
>
> What would ::const_data provide that Module#constants, Module#const_get and Module#const_set and direct constant access don't provide?  If it's something legitimate, invert ::const_data to reference real constants via introspection and get rid of const_missing.

I could, but I wanted to lazy load the information b/c it is being
read from a file, and in most usecases will not be used. The reason I
am using constants is simply b/c it's customary in this case as the
information is project metadata, such as VERSION.

> > I tried `remove_const(:VERSION)` at the toplevel but discovered that
> > some Ruby library don't like that (sorry, can't recall which it was
> > off hand).
>
> File a bug, they should be using RUBY_VERSION.

Will do. I tracked it down to a Ruby 1.8.7:

  e2mmap.rb:fail "Use Ruby 1.1" if VERSION < "1.1"