Re: Abstract Functions

[Ted Dennison<dennison@telepath.com>]

In article <9ihs6j$k33$1@nh.pace.co.uk>, Marin David Condic says...
>
>That is one possible way to go. However, what I have is a working parent
>type that does useful things in its own right. It would be useful to have a
>way of keeping it executable, but adding one or more operations that would
>require extension. Basically, if you have a type that is a few generations
>down the inheritance tree and now want to add some abstract operations, the
>only way to do that is make the whole tree of types abstract. I'd prefer not
>to do that.

It's been a while, but I'm pretty sure you can do an "is abstract new ...", even
if the parent type isn't abstract.

>A question I could get answered by the compiler, but maybe this is less
>typing: Can I have an abstract tagged type that has data fields? My

Yup. Beging able to have non-abstract primitive wouldn't be of much use if there
weren't some existing fields for the subprogram to operate on.

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