From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2001-10-24T04:47:07+09:00
Subject: [ruby-talk:23081] Re: Deprecate keyword? (what does 'module_eval <<END' mean?)

In article <3BD58DB4.2090404@emn.fr>,
Pierre-Charles David  <Pierre-Charles.David@emn.fr> wrote:
>Morris, Chris wrote:

I was looking through your code snippet and there is an idiom that I don't 
understand, so I thought I'd ask and maybe learn something...
>
>----------------------------------------------------
>class Module
>   def deprecate(methodName)

What does this following line mean/do?
>     module_eval <<END
>     alias_method :deprecated_#{methodName}, :#{methodName}
>     def #{methodName}(*args)
>       $stderr.puts "Warning: calling deprecated method 
>#{self}.#{methodName}"
>       return deprecated_#{methodName}(*args)
>     end
>END
>   end
>end
>
>class Foo
>   def print; puts "foo"; end
>end
>
>Foo.new.print
>
>class Foo
>   deprecate :print
>end
>
>Foo.new.print


Phil