Hi --

On Fri, 16 Dec 2005, Mark Ericson wrote:

>> The thrust of duck typing, as I
>> understand it, is that you just ask an object to do something --
>> without regard to its class, and quite likely without doing a
>> respond_to? call first.
>
> I've pondered if duck typing is about an object being able to respond
> to a specific method or if it is about a set of methods.   I also
> wonder if a mechanism like Objective-C's  'protocol' would be useful
> in Ruby.

Here's an example of duck typing:

   def x(a)
     puts a[1]
   end

My x method takes an argument, and sends a message to that argument
without any ceremony or preliminaries of any kind.

Duck typing is really about the programmer, not the object.


David

-- 
David A. Black
dblack / wobblini.net

"Ruby for Rails", forthcoming from Manning Publications, April 2006!