Generics and WO
Generics and WO
- Subject: Generics and WO
- From: Ian Joyner <email@hidden>
- Date: Thu, 10 Aug 2006 17:21:26 +1000
I know Chuck noticed in my code postings that I annotate all my
collections and enumerations with a generic label. For example:
NSArray /*[String]*/ string_array = new NSArray ();
Enumeration /*[String]*/ e = string_array.objectEnumerator ();
but this is just dumb documentation and now Java 1.5 has generics for
real (and they seem to have done a good job with type conformance
rules and constrained genericity (wonder where they got that from,
although they have had enough languages do generics before, even C++
with its awful templates). Real generics get rid of all those
horrible type casts and better still any runtime ClassCastExceptions
(making runtime code more efficient too).
Is there any indication that WO will adopt genericity in the near
future. I have looked at making subclasses of NSArray and
NSMutableArray (XNSArray <T> and XNSMutableArray <T> respectively),
but you can't assign an XNSMutableArray to XNSArray, since
XNSMutableArray <T> is not a subclass of XNSArray <T>.
So you are really stuck with adding the generic parameter to the
original classes, NSArray <T> and NSMutableArray <T>, and this change
does not break any existing code which uses them unparameterized (I
think, I have not read it all yet).
EO- and WODisplayGroup would also be good to have a generic parameter
so you could have
EODisplayGroup <My_entity> dg;
My_entity m = dg.selectedObject (); // No cast or possibility of
run-time ClassCastException.
for (My_entity me: dg.selectedObjects ()) {
... do something to me
}
Any rumblings that genericity might happen soon?
Ian
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