Re: [gobo-eiffel-develop] Comment in {DS_LINEAR}.after misleading?

[Stefan S. <sie...@st...>]

> >The description "Is there no valid position to right of internal cursor?"
> >made
> >me think that 'after' is true whenever the cursor is on the _last_ item of
> >the linear (and not beyond). I assumed that "no valid position to the
> >right"
> >means that the next position will not point to an item of the container
> >anymore.
>
> That assumption is incorrect. The internal cursor has a valid position
> after the last item - the after-life sentinel (my (joke) terminiology).
>
> The point is that when you are on the last item, it is still valid to call
> `forth'. This will move the cursor forward (hence it's name), and the
> cursor has to go somewhere. It goes to the after-sentinel position. Now
> there is no longer a valid position, so you may no longer call `forth'.
Sorry for not being precise enough. Now I know that there's a valid position 
after the last item.
But I was not aware of this when I read the Description of 'after'.  To be 
honest, I was only interested in the items (to iterate through them), so I 
guess this is the reason why I didn't think of the sentinels before and after 
the items.

The description is 100% correct, I just interpreted it in a wrong way. Thus I 
assumed that there will be possibly other people who will get it wrong, too. 
Therefore I thought, it could be worth to think about the description.