From: Richard Lionheart <NoOne@...>
Date: 2004-04-29T05:19:06+09:00
Subject: Re: Last minute details

Hi Mark,

Thanks.  You must be a mind-reader :-)  That's exactly the kind of thing I
wanted to do.  I tried to "undefine" the to_s modification by adding the
following after the invocation of the modified Array:

class Array
    def  to_s
        self.to_s
    end
end

Of course,  that netted me "stack level too deep (SystemStackError)"

Again,  I much appreciate your advice.  It was especially generous of you to
post your complete solution because I might not have known how to apply your
suggestion.  (In this case,  happily,  I understood your suggestion
immediately.)

Regards,
Richard

"Mark Sparshatt" <msparshatt@yahoo.co.uk> wrote in message
news:408FFEBE.8060008@yahoo.co.uk...
> Richard Lionheart wrote:
>
> if you want to save the old version of to_s you can use the alias method
>
> class Array     # Override to_s
>    alias old_to_s to_s
>    def to_s
>         join("; ")
>    end
>  end
>
> then you can access the old to_s behaviour by using the old_to_s method.
> Or if you want to change to_s back to it's default behaviour you can use
>
> class Array
>     alias to_s old_to_s
> end
>
> i.e.
>
> a = %w( foo bar ack)
> puts "After assignment \"a = %w( foo bar ack)\",   a.class.to_s =
> #{a.class.to_s}"
> b = %w(eeny meeny miney mo)
> puts "Before override:  a = #{a.to_s},  b = #{b.to_s}"
>
> class Array     # Override to_s
>   alias old_to_s to_s
>   def to_s
>         join("; ")
>   end
> end
>
> puts "After override:   a = #{a.to_s}, b = #{b.to_s}"
>
> class Array
>   alias to_s old_to_s
> end
>
> puts "After re-override:  a = #{a.to_s}, b = #{b.to_s}"
>
> results=<<RESULTS
> After assignment "a = %w( foo bar ack)",   a.class.to_s =
> Array
> Before override:  a = foobarack,  b = eenymeenymineymo
> After override:   a = foo; bar; ack, b = eeny; meeny; miney; mo
> After re-override:  a = foobarack, b = eenymeenymineymo
> RESULTS
>
> --
> Mark Sparshatt
>
>
>
>


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