From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2005-08-03T05:39:00+09:00
Subject: Re: enum collection of constant values

On Wed, 3 Aug 2005, Joel VanderWerf wrote:

> Ara.T.Howard wrote:
>>   class Object
>>     def enum(*list)
>>       mc = Module === self ? self : self.class
>>       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern, i}
>>     end
>>     def bit_enum(*list)
>>       mc = Module === self ? self : self.class
>>       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern,  2
>> ** i}
>>     end
>>   end
>
> Why would you want the mc = self.class option ?
>
> irb(main):022:0> x=[]
> => []
> irb(main):023:0> x.instance_eval { enum %w{ZZZ AAA} }
> => ["ZZZ", "AAA"]
> irb(main):024:0> ZZZ
> NameError: uninitialized constant ZZZ
>        from (irb):24
> irb(main):025:0> Array::ZZZ
> => 0

isn't this what the op wanted?

   harp:~ > cat a.rb
   def try
     begin
       yield
     rescue => e
       STDERR.puts "#{ e.message } (#{ e.class })"
     end
   end

   class Object
     def enum(*list)
       mc = self
       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern, i}
     end
     def bit_enum(*list)
       mc = self
       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern,  2 ** i}
     end
   end

   try do
     enum %w(
       FOO
       BAR
     )
     p FOO
   end

   class Object
     def enum(*list)
       mc = Module === self ? self : self.class
       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern, i}
     end
     def bit_enum(*list)
       mc = Module === self ? self : self.class
       list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern,  2 ** i}
     end
   end

   try do
     enum %w(
       FOO
       BAR
     )
     p FOO
   end


   harp:~ > ruby a.rb
   undefined method `const_set' for main:Object (NoMethodError)
   0

the 'mc = self.class' is when 'self == main'.  maybe i misunderstood?

regards.

-a
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