From: Mohammad Khan <mkhan@...>
Date: 2004-10-30T01:28:39+09:00
Subject: Re: true? & false?

On Fri, 2004-10-29 at 12:01, trans. (T. Onoma) wrote:
> On Friday 29 October 2004 11:55 am, Mohammad Khan wrote:
> | On Fri, 2004-10-29 at 11:48, Bill Atkins wrote:
> | > Well, all Objects must be nil or non-nil, but the idea of true/false
> | > doesn't apply to all objects.
> |
> | I agree with you on this point.
> |
> | I would ask,
> | If I would like to have true? and false?
> | what would be best class to put in?
> 
> But it must be responded to by all classes.
> 
>   # true?&false?.rb
>   # As suggested by Mohammad Khan
> 
>   class Object
>     def true? ; false ; end
>     def false? ; false ; end
>   end 
> 
In my mind, I had this:

class Object
    def true?
        return self == true ? true : false
    end
 
    def false?
        return self == false ? true : false
    end
end

irb(main):009:0> n = nil
=> nil
irb(main):010:0> n.nil?
=> true
irb(main):011:0> n.true?
=> false
irb(main):012:0> n.false?
=> false
irb(main):013:0> t = true
=> true
irb(main):015:0> t.true?
=> true
irb(main):016:0> t.false?
=> false
irb(main):017:0> f = false
=> false
irb(main):018:0> f.nil?
=> false
irb(main):019:0> f.true?
=> false
irb(main):020:0> f.false?
=> true

>   class TrueClass
>     def true? ; true ; end
>   end
> 
>   class FalseClass
>     def false? ; true ; end
>   end
> 
> Is this what you had in mind?
> 
> T.
-- 
Mohammad Khan <mkhan@lextranet.com>
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