Duck typing alows true polymorfisim

[Simon Forman]

atbusbook at aol.com wrote:
> lets say you want a generic numerical algorithom like sum
>
> Ruby
>
> def sum lst
>   lst.inject(0){|total,current| total*current}
> end
>
> Java // i dont know if there is a numeric super class for numbers
>
> class Sum{
>   public static int sum(int[] lst){
>     int total = 0;
>     for(int current : lst){
>       total+=current;
>     }
>     return total;
>   }
>   // repeat for all other number types
> }

What's your question?  (Or, if no question, point?) :-)

Totally off topic (and indeed "off-list"..) is that really how ruby
sums a list?  How does that work?  Doesn't the '*' mean multiply? and
what are the pipe symbols for?  (Feel free to ignore these questions. I
should really go look it up myself if I'm so curious..)

Peace,
~Simon