Brian Schröäer wrote:

> Hello Group,
> 
> I need more help.
> 
> Gavin Sinclair wrote:
> 
>>
>> p51. Good exercise.  How about another?
>>
> 
> Anybody has an idea for an exercise on extending existing classes. So 
> far the only thing I have come up with is:
> 
> \exercise{Fibonacci II}{
>   Extend \codetype{Integer} with a function fib that calculates the
>   corresponding fibonacci number.}
> 
> And my creativity is at an all time low.
> 

Hi!

what about
- extending REXML::Element with a method that strips all unnecessary 
whitespaces and all children
- extending String so you can tell it to remove cpp comments /* remove me */

Of course both tasks could be accomplished without extending those 
classes. I have no idea in which cases you should write helper methods 
and when you should extend existing classes... does anybody have some 
'heuristics' or best practices?

regards,
Henrik