# from http://redhanded.hobix.com/inspect/stickItInYourIrbrcMethodfinder.html

class Object
  # Clone fails on numbers, but they're immutable anyway
  def megaClone
    begin self.clone; rescue; self; end
  end
end

class MethodFinder

  # Find all methods on [anObject] which, when called with [args] return [expectedResult]
  def self.find( anObject, expectedResult, *args )
    anObject.methods.select { |name| anObject.method(name).arity == args.size }.
                     select { |name| begin anObject.megaClone.method( name ).call(*args) == expectedResult; 
                                     rescue; end }
  end

  # Pretty-prints the results of the previous method
  def self.show( anObject, expectedResult, *args )
    find( anObject, expectedResult, *args ).each { |name|
      print "#{anObject.inspect}.#{name}" 
      print "(" + args.map { |o| o.inspect }.join(", ") + ")" unless args.empty?
      puts " == #{expectedResult.inspect}" 
    }
  end
end

class MethodFinder
   def initialize( obj, *args )
     @obj = obj
     @args = args
   end
   def ==( val )
     MethodFinder.show( @obj, val, *@args )
   end
 end

 class Object
   def what?(*a)
     MethodFinder.new(self, *a)
   end
 end

"hello".what? ==  5
"foo".what?("bar") == "foobar"