From: Kornelius Kalnbach <murphy@...>
Date: 2009-01-31T23:59:06+09:00
Subject: [ruby-core:21694] Re: Definable != is a Bad Thing???

hello, about definable != again :)

We might be using the new != operator in AmberVM, a Ruby interpreter
collection. Part of the ECMA script compiler (racc):

     | rhs '!=' rhs {
       if RUBY_VERSION >= '1.9'
         result = meth(val[0], :'!=', val[2])
       else
         result = meth(meth(val[0], :==, val[2]), :~)
       end
     }

I use '!=' here to make it work with Ruby 1.8, too.

Since the boolean classes don't define ~, I had to do it myself:

  if RUBY_VERSION < '1.9' && !TrueClass.instance_methods.include?('~')
    class TrueClass
      def ~; false end
    end
    class FalseClass
      def ~; true end
    end
  end

It would actually be nice to add these methods to core Ruby 1.8, so !
can be easier simulated.

[murphy]