Re: myWishList

On Sat, 18 Jun 2005, Imam Tashdid ul Alam said:
 > --- Rohan Hart <[email protected]> wrote:
 >> abstract interfaces (or kinds) are (currently?) a weaker statement
 >> than ordinary interfaces in that they are 'provides' vs. 'is a',
 >> ie. you can *only* call methods on a class implementing a kind.

 > erm... completely lost. I *only* call methods on a class
 > implementing an interface.

I bet you also expect to be able to store them in a field?  That's not
possible with abstract interfaces because they exist only at the type
level.

 >> In any case the current implementation is really only adding an
 >> infinite number of commonly recognised Platonic entities to the
 >> set of classes considered for dispatch, in much the same way that
 >> singleton classes are available for dispatch.

 > alright.. erm... I think I understand.

It depends on whether you see something like 3 being a value or type.
I'll leave it to someone like Oleg to show type arithmetic in Nice.
See http://okmij.org/ftp/Computation/type-arithmetics.html and
http://okmij.org/ftp/Haskell/number-parameterized-types.html for
examples in C++ and Haskell.
 
 >> Closed vs. open enumerations is a slightly different topic.  I
 >> think Java provides both.

 > does it? could you give me an example?

Sorry, by "I think" I really meant "I've never used Java1.5 enums and
this is based on vague recollections from the 'whatsnew in Java1.5'
pages"


Rohan



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