From: Morton Goldberg <m_goldberg@...>
Date: 2007-09-06T13:12:53+09:00
Subject: Re: before, after and around Ruby 1.9

On Sep 5, 2007, at 7:32 PM, Yukihiro Matsumoto wrote:

> Hi,
>
> In message "Re: before, after and around Ruby 1.9"
>     on Thu, 6 Sep 2007 03:07:14 +0900, Trans <transfire@gmail.com>  
> writes:
>
> |Any chance Ruby 1.9 will have before, after and around method
> |composition support?
>
> No.  Wait for 2.0 for built-in method combination.  The vague plan is
> making open-class to stack methods on the current ones, unless
> explicitly removed, i.e.
>
>   class Foo < Object
>     def foo
>       puts "Foo#foo (1)"
>     end
>   end
>   class Foo # re-open
>     def foo
>       super  # calls the first foo
>       puts "Foo#foo (2)"
>     end
>   end
>
> will print
>
>       Foo#foo (1)
>       Foo#foo (2)
>
> No alias required.
>
> This works as "around".  And "before" and "after" can be rewritten
> using "around".  Note that this is not a fixed idea at all.

Perhaps to avoid overloading 'super', you might use 'previous' or  
'existing' since we would be calling a previously existing version of  
the method.

class Foo < Object
   def foo
     puts "Foo#foo (1)"
   end
end
class Foo # re-open
   def foo
     previous
     puts "Foo#foo (2)"
   end
end

lass Foo < Object
   def foo
     puts "Foo#foo (1)"
   end
end
class Foo # re-open
   def foo
     existing
     puts "Foo#foo (2)"
   end
end

Just a suggestion.

Regards, Morton