Collection interfaces

[Greg Ewing]

Topmind wrote:
> 
> There is no polymorphism if there is
> only one "type" with a bunch of independant attributes -
> HAS-A reigns and sub-IS-A is rare.

Polymorphism is not inherently dependent on any 
kind of inheritance or classification system.
In Python, for instance, most functions are quite
promiscuous and will happily operate on any
objects which have the right methods, without there
having to be any inheritance relationship between
them.

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg