From: Brian Candler <b.candler@...>
Date: 2010-09-23T22:07:42+09:00
Subject: Re: to make dot method dot method work?

When you call foo.bar.baz then you are:
1. calling method 'foo'
2. that returns an object
3. calling 'bar' on the object returned from (2)
4. that returns an object
5. calling 'baz' on the object returned from (4)

So:

> class  Mycompute
>   def initialize(str)
>     @str=str
>    end
>   def values
>     @@result=@str
>    end
>    def up
>      @@result.upcase
>    end
> end
> irb(main):012:0> Mycompute.new("Abc").values
> => "Abc"
> irb(main):013:0>
> irb(main):014:0* Mycompute.new("Abc").up
> => "ABC"

That returns a string (and sets @@result as a side-effect).

> irb(main):015:0> Mycompute.new("Abc").values.up
> NoMethodError: undefined method `up' for "Abc":String
>   from (irb):15
>   from :0

Strings don't have a method called 'up' - but they do have 'upcase'.

So you can do:

Mycompute.new("Abc").values.upcase

Or else perhaps this is what you want:

obj = Mycompute.new("Abc")
obj.values
obj.up

Or else:

  def values
    @@result = @str
    self
  end

in which case Mycompute.new("Abc").values.up will work, because your 
values method returns the object itself, not a String.
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