Meta-programming in Ruby : Part 2 : Method Missing

Code 1

class Hash
    def method_missing(m,*a)
        if m.to_s =~ /=$/
          self[$`] = a[0]
        elsif a.empty?
          self[m]
        else
          raise NoMethodError, "#{m}"
        end
    end
end

x = {'abc' => 123}
p x['abc']
print "\n"

x.foo = :baz
x.goo = "duh"
x.x&z = 10
p x

Result 1

[root@localhost ruby_tutor]# ruby method_missing1.rb
123

{"abc"=>123, "foo"=>:baz, "goo"=>"duh"}

Code 2

class Hunt
   @@arr = []
   def show;
       @@arr;
   end

   def method_missing(name, *args)
      begin
           @@arr.send(name, *args)
      rescue
          "'#{name}' method has NOT been implemented YET"
      end
   end
end

he = Hunt.new

he << 123
he << "Be happy, Son!"
p he.show
puts he.flyswim

Result 2

[123, "Be happy, Son!"]
'flyswim' method has NOT been implemented YET

Code 3
Remember that method_missing will provide a block if one is given

def method_missing(name, *args, &block)
  block.call(*args) if block_given?
end

no_method("Ask","why", "study this !"){ |*args| p args }

Result 3

[root@localhost ruby_tutor]# ruby  method_missing_bloc_CROSS-REF.rb
["Always demand", "why you have to", "study this or that or whatever!"]