On 24 Mar, 17:54, Alan <a...@malloys.org> wrote: > On Mar 24, 9:47 am, Alessio Stalla <alessiosta...@gmail.com> wrote: > > > Reflection is aware of generic type > > variables:http://download.oracle.com/javase/6/docs/api/java/lang/reflect/Generi... > > > What is lost at runtime is information about *instantiation* of those > > variables: e.g. you can't distinguish a method returning List<String> from > > one returning List<Integer>. > > I think you mean, you can't tell a List<String> from a List<Integer> > once it's been returned. As you demonstrated, telling which kind of > list a particular method will return can be done via reflection.
Only if the method is defined in a class that instantiates a type variable, e.g. String get(int) in class MyList implements List<String>, where the superclass is List<T> and defines T get(int). But if you have class Foo<T> with a method T bar(), you can't tell via reflection the distinction between new Foo<String>().bar() and new Foo<Integer>().bar() - they're the same method of the same class at runtime. Similarly if you have a method <T> List<T> foo(...) you can't know about the different instantiations of T for calls to foo(). > > (Actually, not even all instantiations of > > generic type variables are lost at runtime, > > seehttp://gafter.blogspot.com/2006/12/super-type-tokens.htmlforan example). > > That's really nifty. Thanks for the link. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
