[Newbies] closed and open interval

[Bert Freudenberg]

On 24.11.2008, at 17:46, Randal L. Schwartz wrote:

>>>>>> "Filip" == Filip Malczak <filet00 at gmail.com> writes:
>
> Filip> You can always make subclass of Interval for example  
> OpenedInterval , add
> Filip> two variables: left and right.Make new methods:
> OpenedInterval> from: aNumber to: aNumber left: aBoolean
> OpenedInterval> from: aNumber to: aNumber right: aBoolean
> OpenedInterval> from: aNumber to: aNumber left: aBoolean right:  
> aBoolean
>
> You're exposing implementation there.

How so?

- Bert -