From: Trans <transfire@...>
Date: 2007-11-12T22:00:45+09:00
Subject: Re: does Ruby has method properties



On Nov 12, 3:35 am, Thilina Buddhika <thilin...@gmail.com> wrote:
> In java script it is possible to something like this,
> method.outputType = "string";
>
> we are setting the return type of the method.  Is this possible in Ruby?
>
> i searched in the google and found this.
>
> http://bias2build.com/thesis/ruby_v_js_MP.html
>
> it says that this is not possible in Ruby.
>
> i wanna confirm this.
>
> help me please.

It is possible in a round about way. In Ruby, methods are not first
class objects. (Though to go with Ruby's 100% OOP mantra you would
think they would be, but in any case...) You can make them behave as
such for the most part if you want. You have to create a method cache,
b/c #method itself will always return a new object rather than the
same one. Facets does this with #method!.

  require 'facets/1stclassmethod'

  class X
    def initialize
      meth = method!('sayit')
      def meth.outputType
        "String"
       end
    end

    def sayit(msg)
      puts msg.to_s
    end

    def tellme
      method!('sayit').outputType
    end
  end

  puts X.new.tellme  #=> String

Besides #method! there is also #instance_method!. You have to realize
the limitations of this though. In Ruby instance methods are not the
same as object methods (shown above). So:

  X.instance_method!('sayit') != X.new.method!('sayit')

T.