RE: [xacml] straw poll on "<type>-map" or "map"

[Polar Humenn <polar@syr.edu>]

On Tue, 26 Nov 2002, Daniel Engovatov wrote:

> > As for the "type-bag", "type-one-and-only", "type-bag-size" functions, I
> >would be very happy if they were polymorphic as well. The type is pretty
> >meaningless to their functionality. However, the function "type-is-in"
> >calls an implicit function "type-equal" to handle the membership
> >determination. So, it can be said that it is needed.
>
> Why would you be happy?  Would it make for a  simpler, faster and more
> efficient implementation for a variety of languages and architectures?

That depends on the capability of the implementors, and the languages and
architectures chosen.

> What is the reason for introducing polymorphic functions beyond it being a
> "cool" feature?  Use case?  Sample implementation that we can see, how it
> useful?

I don't know what "cool" is.

Use case:

If I introduce a new type, say "FingerPrint", and I use an
AttributeDesignator to retrieve attributes of that type, I don't have to
create a new function "FingerPrint-bag-size" to find out how many I have
when I do retrieve them, I can just use the same old function "bag-size".
Likewise, if I create a function called "FignerPrint-to-Characteristic" I
don't have to create a new function "FignerPrint-map" (or would it be
"Characteristic-map"?) to convert a bag of FingerPrint values to a bag of
Characteristic values. I would just use the same old "map".

Now, how you implement it, is up to you. You certainly wouldn't be
precluded from creating "FingerPrint-bag-size". or FingerPrint-map (or
Characteristic-map?).

Sample implementation:

I've already gone over how you can do most of this with Java interfaces,
of which you can do the analogous thing with C++.

Cheers,
-Polar

> Daniel;
>
> ----------------------------------------------------------------
> To subscribe or unsubscribe from this elist use the subscription
> manager: <http://lists.oasis-open.org/ob/adm.pl>
>