Nick Name wrote:

On Sun, 19 Jan 2003 16:02:41 -0600 Jon Cast wrote:

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But, to fully exploit the power of a "functionally-programmed" desktop, the interface should allow the user to map an operation onto all the objects of the panel; in this case the allowed operations should be those that all the object share.

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This is fairly easy if you name the operations; then you can use that to compute the intersection of the operations for all the types. If you don't name the operations, then of course the problem becomes undecidable.

Another idea: if I allow the list of objects in the panel to be infinite,

Sorry, but I'm having difficulty figuring out where you'd get an infinite list of objects to put in the panel. I suspect any solution is going to depend on how the list of objects is put together.

obviously the set of allowed operations in a map is the set of operations on "objects". But if I filter an infinite list of objects to all the objects of a certain type, I wish to see all the operations on that type in the possibilities for a map.

If you have a finite list of the types of your objects, then you can list the operations available at each type and use that to get the intersection, I suppose.

How would you deal with such a case?

Vincenzo